How Resistant Starch Will Help to Make You Healthier and Thinner


I asked Dr. Amy Nett, MD, to contribute this guest post. She recently joined my private practice and will be working with me in the clinic.  Amy initially completed her medical training in radiology at Stanford University Hospital, but wanted to work more directly with patients, helping them to prevent and reverse chronic disease and truly transform their health.  Combined with her passion for nutrition she decided to pursue a career in functional medicine, and is excited to have the opportunity to work more closely with patients in achieving their goals and realizing their best potential.  You’ll be hearing more from Amy in the future!

Over the past several years there has been an exponential increase in the number of studies linking imbalances or disturbances of the gut microbiota to a wide range of diseases including obesity, inflammatory bowel diseases, depression and anxiety (1,2,3,4,5).  One of the best ways to establish and support a healthy gut microbiome is by providing the right “foods” for your gut bacteria.  These “foods” are called prebiotics.

Why you should add resistant starch to your diet.

Prebiotics are indigestible carbohydrates, or at least indigestible to us, that reach the colon intact and selectively feed many strains of beneficial bacteria.  Prebiotics are generally classified into three different types: non-starch polysaccharides (such as inulin and fructooligosaccharide), soluble fiber (including psyllium husk and acacia fibers), and resistant starch (RS).  Each of these types of prebiotics feeds different species of gut bacteria, but among these, RS is emerging as uniquely beneficial.

The distinctive benefits of RS seem to be unequivocally recognized, even amongst advocates of a low carbohydrate diet

What is resistant starch?

Resistant starch is a type of starch that is not digested in the stomach or small intestine, reaching the colon intact.  Thus, it “resists” digestion.  This explains why we do not see spikes in either blood glucose or insulin after eating RS, and why we do not obtain significant calories from RS.  

There are four types of resistant starch:

RS Type 1: Starch is physically inaccessible, bound within the fibrous cell walls of plants.  This is found in grains, seeds, and legumes.

RS Type 2: Starch with a high amylose content, which is indigestible in the raw state.  This is found in potatoes, green (unripe) bananas, and plantains.  Cooking these foods causes changes in the starch making it digestible to us, and removing the resistant starch.

RS Type 3: Also called retrograde RS since this type of RS forms after Type 1 or Type 2 RS is cooked and then cooled.  These cooked and cooled foods can be reheated at low temperatures, less than 130 degrees and maintain the benefits of RS (6).  Heating at higher temperatures will again convert the starch into a form that is digestible to us rather than “feeding” our gut bacteria.  Examples include cooked and cooled parboiled rice, cooked and cooled potatoes, and cooked and cooled properly prepared (soaked or sprouted) legumes.

RS Type 4: This is a synthetic form of RS that I’m including for completeness, but would not recommend.  A common example is “hi-maize resistant starch.”

Once RS reaches the large intestine, bacteria attach to and digest, or ferment, the starch.  This is when we receive the benefits of RS.

How resistant starch impacts our health

The normal human gut has hundreds of bacterial species, some good and some not so good.  The overall number and relative quantity of each type has a profound effect on our health and well being.  Resistant starch selectively stimulates the good bacteria in our intestines, helping to maintain a healthy balance of bacteria (7).

These good bacteria “feed” on RS and produce short chain fatty acids (through fermentation), the most significant of which are acetate, butyrate, and propionate.  Of these three short chain fatty acids (SCFA), butyrate is of particular importance due to its beneficial effects on the colon and overall health, and RS appears to increase butyrate production more when compared with other soluble fibers (8).

Butyrate is the preferred energy source of the cells lining the colon, and it also plays a number of roles in increasing metabolism, decreasing inflammation and improving stress resistance, as described in more detail below and previously in this great article by Stephan Guyenet.

Resistant starch helps to lower blood glucose levels and improve insulin sensitivity

Insulin resistance and chronically elevated blood glucose are associated with a host of chronic diseases, including metabolic syndrome.  Several studies have shown that RS may improve insulin sensitivity (9), and decrease blood glucose levels in response to meals (10, 11, 12).  In one study, consumption of 15 and 30 grams per day of resistant starch showed improved insulin sensitivity in overweight and obese men, equivalent to the improvement that would be expected with weight loss equal to approximately 10% of body weight (13).

Further, RS has been shown to exert a “second meal effect.”  This means that not only does RS beneficially decrease the blood glucose response at the time it’s consumed, but, somewhat surprisingly, blood glucose and insulin levels also rise less than would otherwise be expected with the subsequent meal (14).

Why the popular press has touted resistant starch as a “weight loss wonder food”

RS appears to have several beneficial effects that may contribute to weight loss, including decreased blood insulin spikes after meals (as discussed above), decreased appetite, and decreased fat storage in fat cells.  There may also be preservation of lean body mass, though further studies in humans are needed to confirm if there is a significant impact in overall body weight (15).

Further, several studies have shown alterations in the gut microbiome in association with obesity, which subsequently change towards that seen in lean individuals with weight loss (16, 17).  For example, one study demonstrated that the relative composition of the gut microbiota of two predominate beneficial bacteria, Bacteroidetes and Firmicutes, varied considerably in association with body composition.  Specifically, obese individuals often have a higher proportion of Firmicutes to Bacteroidetes, which may be reversed with weight loss, gastric bypass surgery, or treatment with prebiotics (3).  However, not all studies confirm a significant or measurable change in the composition of the microbiome in obese compared to lean individuals, and further studies are needed (18, 19).

Butyrate plays an important role in gut health and decreasing inflammation in the gut and other tissues

As mentioned above, RS intake allows for increased production of butyrate by our gut microbes.  Butyrate acts as a powerful anti-inflammatory agent for the colonic cells, and functions to improve the integrity of our gut by decreasing intestinal permeability and therefore keeping toxins in the gut and out of the bloodstream. (20, 21).  

The SCFAs that aren’t utilized by the colonic cells enter the bloodstream, travel to the liver, and spread throughout the body where they exert additional anti-inflammatory effects.

Resistant starch is also associated with decreased risk of colorectal cancer, thought to occur through several different mechanisms including: protection from DNA damage, favorable changes in gene expression, and increased apoptosis (programmed cell death) of cancerous or pre-cancerous cells (22, 23).

Adding resistant starch to your diet

Some common food sources of RS include green (unripe) bananas, plantains, properly prepared cooked and cooled parboiled rice or legumes, and cooked and cooled potatoes.  See this link for a more complete list of RS quantities in food.

However, if you are on a low carbohydrate diet or don’t tolerate those foods well, you can add RS to your diet without adding digestible carbohydrates.

Bob’s Red Mill Unmodified Potato Starch (NOT potato flour) is one of the best sources of RS with approximately eight grams of RS in one tablespoon.  Potato starch is generally well tolerated even by those who react adversely to nightshades.

Plantain flour and green banana flour are also excellent sources of RS, and there may be benefit to including all three of these sources (specifically alternating your source of RS rather than relying on a single one).

These are relatively bland in flavor and can be added to cold or room temperature water, almond milk, or mixed into smoothies.  But to maintain the benefits of RS, these should not be heated above 130 degrees.

Tim Steele (Tatertot) has written about some of the research on RS supplementation, and in particular the potential further benefit of combining potato starch with psyllium husk fiber to even further increase butyrate production in the colon.

Take it slow

If you choose to try supplementing with RS, start with small doses of about ¼ teaspoon once daily, and very gradually increase the amount as tolerated.  Some increased gas and bloating is expected as your gut flora changes and adapts, but you do not want to feel uncomfortable.  If you experience marked discomfort, then decrease the amount you’re taking for a few days until your symptoms resolve, and then try increasing again gradually.

Studies indicate that the benefits of resistant starch may be seen when consuming around 15 to 30 grams daily (equivalent to two to four tablespoons of potato starch).  This may be too much for some people to tolerate, particularly in the setting of gut dysbiosis, and going above this amount is not necessarily beneficial.

If you experience marked GI distress with even small amounts of RS, this may be an indication of SIBO (small intestinal bacterial overgrowth) or microbial dysbiosis, and you may need to consider working with a healthcare practitioner to establish a more balanced gut microbiome through the use of herbal antimicrobials and probiotics before adding RS or other prebiotics.

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Comments Join the Conversation

  1. Peggy says

    I would love for anyone to answer this question:
    Monday I ate a dish containing 1/3 cup of white rice.
    Post meal checks showed that my blood sugar topped off at 151. Today I ate the same dish with the same amount of COOLED white rice. In addition, I ate two small RAW potatoes beforehand in an attempt to increase the resistant starch. However, after eating the rice dish, my blood sugar topped off at exactly 151 again. It appears the resistant starch had no glycemic lowering effect. Thoughts?

    • says

      Peggy – You are seeing that RS is not a “pill” for lowering blood-glucose. Your experiment has been replicated many times in the lab, with the same results…no effect.

      However, when you allow the RS to do what it is good at, ie. making beneficial changes to your gut flora, and in turn, a host of metabolic improvements, then you may start to see the BG lowering effects.

      Also, BG improvements are generally seen as improvements to the “are under the curve” (AUC). To see this for yourself, you’d need to test your post-prandial blood glucose at about 10 minute intervals after eating, plot out a chart, and then do the exact same chart later to compare to a baseline. This is actually a very enlightening experiment, and if you have unlimited strips, I would suggest you do it.

      For instance, the first meal you describe above, possibly your pp BG spiked to 200 at the 30 minute mark, but was at 150 when you tested it. In the second meal, maybe it only spiked to 170 at its highest, but you managed to capture it at 150 again.

      A single BG poke is simply a snapshot of your GB at that instance and does not give a picture of the journey it took getting there.

      Hope that helps!

      Bottom-line: RS increases insulin sensitivity, but may take time. To see if it is working, a baseline curve must be developed to compare against.

      • Peggy says

        Tim, I really appreciate your response. I did check my BG every 15 minutes for about 3 hours after eating the rice. (BTW, I found it took about 3 hours for my BG to return to baseline.) It sounds like I need to try the potato starch and stick with it long enough to give it a chance to improve my gut flora and see what other positive effects it might have. I will do the graph as you suggested. Thanks!

  2. Leon says

    Hello Chris.

    I think i have some Form of leaky gut so therefor i drink kefir everyday.

    I usually do a second fermentation with prebiotics like Onions or plátano starch to give the probiotics a head start on consuming them before they arrive the small intestines in csse i have SIBO.

    Does this make sense?

  3. Leon says

    Grainbrain by Dr. Purlmutter says that corn, potatoe and soybeans are no nos. You say that rs upon cooking at high temp will convert them to a digestible form. But if one uses the high temp and then cool to 130 degrees or less will render them undigestible and they will go to the gut to for prebiotics.

    I just want to make sure that I read all of this correctly.

    Also, I froze greek yogurt and wonder if the probiotics would be dead and if so is there a way of adding probiotics back to it?

  4. Estelle Shukert says

    I’m not looking for weight loss or improvement in my gut! My gut has never given me any problems, for which I am thankful. However, I have been on the Paleo Approach diet for about 6 months now. I had several borderline and slightly elevated blood tests which are now in the normal range. But I am losing more weight that I thought I would, so am beginning to add a few things back into the diet. I’d appreciate any comments or other suggestions. Blessings and thanks, Estelle

  5. Amanda says

    I really need some Inf. about how producers produce RS in industrial scale??
    If there is special instrument or methods, what are they??
    I’d be thank full if you help me by this issue.

  6. missy whitford says


    I have just bought a packet of unmodified potato starch, i wanted to know if it is ok to soak it overnight in milk before taking it, or if the milk and or the soak would be detrimental to the resistant starch?

  7. says

    Thank you so much Dr Amy for this very clear article!
    I am have been curious to know why there is a recommendation across the board in our community regarding using Bob’s Mill Potato starch. I understand that it is not organic and they do not have any specially high standard for sourcing the potatoes. I have seen evidence that potatoes may be one of the most contaminated foods in the dirty dozen list. I put my two cents here, for us to start recommending organic potato starch. Thanks again for the great article! It has been very helpful! Cheers!

    • Paleophil says

      Bob’s Red Mill potato starch happens to be what the guy who inspired the potato starch experiments tried. It was the one he happened to find at the supermarket and it’s also relatively cheap. If you’re concerned, there is at least one organic brand and there are other alternatives. You can even make your own.

      • says

        Thanks Paleophil. Very kind of you to reply. Actually, I am covered. I have always used the organic one only and find it awesome!
        The purpose of my post was to invite whoever is interested, to question the use of the conventional starch, which seems to have become the “norm” across the web. Cheers.

        • says

          How timely, I just put together a page with links to RS products I have thoroughly checked out and use. My RS2 Picks

          The term “unmodified” is not as important as seeing the term “modified”. When buying look specifically for the terms “modified” or “pre-gelled” these are definitely not the right product!

          Until someone develops a resistant starch supplement that has been tested for RS, it’s a bit of a crap-shoot. Hi-Maize cornstarch is about 54% RS2 and has been used in 1000’s of studies. You can find a link at the above page, but in 50 pound bags.

  8. Wendy Pasco says

    Just a note that Hi-Maize is a Resistant Starch 2 and not a chemically modified starch which is Resistant Starch 4. Hi-Maize has numerous health benefits ranging from Digestive Health to Blood sugar management.

      • says

        I finally got around to looking at Hi-Maize. It is non-GMO certified, but not organic. It can be cooked with, to a point, the RS surviving most gluten-free baking methods, or used in a smoothie.

        I made some pancakes yesterday with about 50% Hi-Maize…turned out great.

        This is the stuff. Hi-Maize 260, 50 pound bags, $140

        The info says it also comes in 5 pound bags, not sure how to get those.

        • Lesley says

          Hi, I’m hypothyroid and have discovered that any form of maize (corn) is bad for thyroid health; so are most soy products.

  9. Trilife says

    Thanks for a great article.

    In it, there are several references to “properly cooked” and parboiled rice.

    1- Can you please elaborate on “properly cooked”?

    2- Can you please explain the difference between parboiled rice and brown rice in this context?


  10. Reta Vong says

    Starches are long chains of glucose that are found in grains, potatoes and various foods.

    But not all of the starch we eat gets digested.

    Sometimes a small part of it passes through the digestive tract unchanged.

    In other words, it is resistant to digestion.

    This type of starch is called resistant starch, which functions kind of like soluble fiber

    Many studies in humans show that resistant starch can have powerful health benefits.

    This includes improved insulin sensitivity, lower blood sugar levels, reduced appetite and various benefits for digestion.

    Resistant starch is actually a very popular topic these days. In the past few months, hundreds of people have experimented with it and seen major improvements by adding it to their diet.

  11. says

    I have a rather unique perspective on the question of resistant starch fiber. I am a diabetic of over 20 years. Started out as type two, but lost the weight and am now normal weight, no longer insulin resistant and no trouble keeping the weight off. I am 76 years old and in perfect health other than my old pancreas doesn’t make quite enough insulin anymore so I take a little to make up for the shortfall and get almost all my carbohydrates from fruits and vegetables.

    I attribute enduring my good health even with diabetes, to
    resistant starch fiber. Hi maize 260 to be exact. Hi maize 260 is made from non GMO corn especially hybridized (the bees and humans do it). Hi maize 260 is not the chemical form of resistant starch fiber, although a chemical form is made. The Australians developed the non chemical form.

    I found Hi maize 260 in 2007 and have been doing my own research on it ever since. I can keep my weight down, my blood sugar down and my digestion ship shape. Since I tested my blood because I am diabetic, I was able to see the relationship of the Hi maize 260 resistant starch fiber to my weight and blood sugar. I also test inulin made from chicory root. It has benefits too, but can cause gas if used in liquids.

    Hi maize 260 is a soluble fiber. It keeps cholesterol in check as soluble fibers are known to do. I run a diabetes support group and the participants test Hi maize 260 with the same results as mine. It really helps with weight loss and. diabetes drugs are lowered. I use two to three tablespooons per day
    raw. You can cook and bake with It too, but it is more effective raw. At least that is what I found. I have figured out many ways to use it both raw and in cooking and baking.
    I have been using the Hi maize 260 daily for 8 years. I have no health problems at all. Oh yes it cures constipation real well too.

  12. Daisymouse says

    Hi there all..

    A few questions..
    If resistant starch is so vital how would people have got it in to their diet prior to the days of being able to eat potato starch? Just trying to understand how a vital part of good gut health would have been accessible to our ancestors?

    Plus, I am a little confused about different recommendations such as resistant starch, soluble fiber, un-soluble fiber
    Feel a little like head is exploding..
    Which do you need and how much and what foods are they in and which are ok/not ok if you have compromised gut/immune system?
    So, if one is dealing with gut dysbiosis, candida and possibly SIBO plus CFS, (fatigue is my main symptom including adrenal fatigue), is it ok to add RS to the diet?…(currently on a relaxed version of GAPS) … without any adverse affects? What can one expect in terms of symptoms? Worse before better etc and will there be progress in the long run?

    Some have said a period of keeping these out is helpful but how long is not stipulated…
    Then I read about foodmaps which adds additional confusion to the mix!

    Also, with these situations it is all a bit chicken and egg and is hard to know which symptom to deal with. I have seen Drs who say once the immune system functions better, (through healing the mitochondria…Dr Myhill has lots of vital info on this). That is, once the CFS and ME is better, the gut will have the ability to sort itself out. Others say that until you heal the gut the ME/CFS will remain a problem… Jesus… See my problem??!

    I appreciate fully that the answer to a lot of this will be ‘we don’t know yet’… I am sure 50 yrs from now we will be sorting these things out in a matter of weeks… Hope for our children right? However, if anyone out there has information or expertise that can clear up some of the confusion it would be so great to hear from you.

    Oh, one other thing… I am sure I need betaine HCL. Took it for 3 days last year with amazing results on digestion but as I have IC, it caused a flare that lasted 6 months…. At least I think it was that. Assuming I hence cannot take it, what would you recommend to assist low HCL?

    Many thanks,

    P.s. This is the first time I have ever posted anything on-line, being a technophobe and pretty ill last 5 yrs so I consider this progress! :)
    P.P.S. I am in the UK in case this affects info or recommendations.

    • says

      Great first post. Welcome to the internet!

      Let me just give my 2 cents where I can…

      “If resistant starch is so vital how would people have got it in to their diet prior to the days of being able to eat potato starch? Just trying to understand how a vital part of good gut health would have been accessible to our ancestors?”

      – Our ancestors ate loads of RS and other fibers, the modern diet is nearly devoid of them. Prior to the invention of cooking, we ate raw plants out of necessity. Our gut bacteria evolved for millions of years as we ate tubers, roots, seeds, leaves, etc… all full of RS and fiber. Even after we started cooking, we still ate loads of RS and fibers. As man marched out of Africa, he sought out starches such as sago, cattail, potato, rice, taro, corn, and more. Much was eaten raw, much was cooked, much was cooked and cooled…each way of eating providing different sources and types of fiber and RS. It’s only been in the past few hundred years that our fiber intake has gotten to critically low levels. Even eating grains roughly milled as they were when we first started farming provided ample fiber. Our modern preoccupation with soft, white bread and everything eaten hot and freshly cooked took most of the fiber out of our bellies.

      “Plus, I am a little confused about different recommendations such as resistant starch, soluble fiber, un-soluble fiber.”

      – It’s a difficult concept, I’ll agree. If you are eating several servings of beans, whole grains, and cooked and cooled starches daily, in addition to several servings of fruit and veggies, you are probably getting enough “fiber”. If you don’t eat beans, grains, and little fruit or veggies, you could do with supplemental fiber. Most people find that raw potato starch is a good, cheap RS source. Start with a small spoonful and work your way up to a couple spoonfuls a day. Maybe a spoonful with each meal. Mix it in yogurt, milk, water..whatever. Just don’t heat it! Some people hate potato starch…no problem. Buy some inulin powder, psyllium husk, flax seeds, pectin, glucomannan, or any other normal fiber supplement sold in stores. I’d stay away from any that have strange ingredients or are mostly cellulose. And actually, a mixture of several different fiber types is best and emulates ancestral eating much better than one fiber type, such as potato starch.

      “is it ok to add RS to the diet?…(currently on a relaxed version of GAPS) … without any adverse affects? What can one expect in terms of symptoms? Worse before better etc and will there be progress in the long run?”

      – It’s impossible to give advice that pertains to everyone except, “be kind to your gut flora!” Try starting slow with fibers that make sense to you, and make you feel better. A diet devoid of fiber is not healthy in the long-run, even if adding fibers makes you feel worse in the short-run. 1 spoonful of potato starch doubles or triples most people’s fiber intake for a day! If you are used to 3-5g/day of fiber, adding 8-10g will be noticeable. But your gut flora should quickly adapt and you’ll find you may even want to add more, and more diverse fiber types.

      “…once the CFS and ME is better, the gut will have the ability to sort itself out. Others say that until you heal the gut the ME/CFS will remain a problem…”

      – It is going to be completely individual how you respond. Adding fiber/RS is a new twist on all of this. The gut is so vitally important, it doesn’t make sense to me to delay adding fibers in any scenario unless your gut is so dysbiotic that any added fibers give you terrible gastric upset. In the cases where people respond poorly to extra fiber, it usually means they have gut bacteria that is completely wrong for a human. In this instance, the only way to get to the root cause is gut testing and through trial and error of fiber intake/dietary tweaks.

      “I am sure I need betaine HCL. Took it for 3 days last year with amazing results on digestion but as I have IC, it caused a flare that lasted 6 months…. At least I think it was that. Assuming I hence cannot take it, what would you recommend to assist low HCL?”

      – IC…Interstitial Cystitis? Betaine HCL, a supplement to increase stomach acid?

      Have you been diagnosed low stomach acid? I wouldn’t mess with stomach acid unless there was a really good reason. Doctors love putting people of meds that lower stomach acid (PPIs) with often terrible long-term outcomes. Interstitial cystitis has largely unknown causes. Maybe auto-immune, but not always. Sometimes it just “goes away”. But I would think that getting the gut in order through a very healthy, fiber-filled diet resulting in a healthy gut pH and healthy gut flora would aid in keeping IC under control.

      How did I do?

      • Charlotte Parfitt-reid says

        Hi Karen, IC .. It is my belief that IC is not a autoimmune disease of unknown origin but a chronic embedded bacterial infection. Urine testing is so antiquated and inadequate that it is believed that over 70% of infections are not picked up, in the early stages allowing bladder biofilms to develope. I help run a support group in the UK For ladies with the condition who are under the two Doctors in the country who believe this is what IC is … They are getting people better everyday . Contact me if you want to know more
        Lottie xx

      • Charlotte Parfitt-Reid says

        Yes Tim , I’ve posted below about “IC”, the bladders equivalent of IBS ie there is something wrong but we haven’t a clue as to what but let’s give it a name anyway. Improving ones gut health is imperative in fighting of this infection, and my personal belief is that it is poor gut health which allows this infection to take a hold in the first place.
        Lottie x

    • Paleo Phil says

      Hi Daisymouse, Ancient ancestral sources of RS included such foods as tiger nuts, marama beans, marama legume tubers, ekwa legume tubers, false banana pith, African yams (Dioscorea), palm tree pith (Hearts of palm aka sago, palm cabbage, ubod), Bulrushes, Cattails, Chestnuts, Water chestnuts, Eskimo potatoes (Claytonia tuberosa and Hedysarum alpinum), and Siberian potato (Sarana). These ancestral foods tend to get overlooked in Paleo and LC circles. A famous more recent traditional UK source of RS is “pease porridge cold, nine days old.” :)

      Whether a fiber or microbiota accessible carbohydrate (MAC) is soluble or not is less important than whether it is fermentable. Caution has been advised when dealing with SIBO and other GI issues. For more info, see Tatertot Tim’s resistant starch thread at Mark’s Daily Apple and Jeff Leach’s articles at the Human Food Project and Norm Robillard’s articles and responses to readers on SIBO, resistant starch and related topics. Re: FODMAPs, Chris Kresser covered that in the past.

      Nature is infinitely complex, so you have lots of reading ahead of you. :) You’re right that much is still unknown. I also encourage you to do your own investigation of the topics and figure out what works for you, which may be different than for others.

  13. Kelly says

    So given that cooked and cooled potatoes count, would cooked and cooled potato starch count too? I am thinking about muffins using potato starch, and then eaten cold. Thanks!

    • Duck Dodgers says

      The dirty secret of the Paleo™ world is that anti-nutrients all have documented benefits when consumed as part of a varied diet from domesticated foods.

      A 1992 review paper even called the term “anti-nutrient” into question, saying: “…Phytic acid, lectins, phenolic compounds, amylase inhibitors and saponins have also been shown to reduce the blood glucose and insulin responses to starchy foods and/or the plasma cholesterol and triglycerides. In addition, phytic acid, phenolics, saponins, protease inhibitors, phytoestrogens and lignans have been related to reduced cancer risks. Because antinutrients can also be mitigating agents, they need re-evaluation and perhaps a change in name in the future”

      As for lectins, they too have benefits. For instance…

      Lectins can reverse the distal intestinal atrophy associated with elemental diets in mice (2002)

      “In conclusion, we have demonstrated that lectins, such as Con-A and PHA, at doses below those likely to elicit harmful metabolic changes in body metabolism, can have a significant trophic effect on the small intestine or the colon, and may be beneficial in reversing the profound intestinal atrophy associated with elemental diets.”

      While indigenous hunter gatherers certainly took steps to reduce toxins and anti-nutrients, they did so in the context of wild plants. Whereas modern societies have already taken steps to reduce plant toxins by hybridizing and domesticating plants which now have far less phytotoxins than their wild counterparts.

      The Paleo™ narrative of fearing plant toxins is mostly a sloppy attempt to scare people away from carbohydrates. The logic fails when you investigate what plants hunter-gatherers actually consumed.


  14. Samantha says

    I’m trying to find out if sprouted seeds and legumes in particular sprouted sunflower seeds and sprouted lentils contain resistant starch? If so how much? Can anyone help me please?

  15. Quinny says

    Hi Chris,
    Is your Prebiogen considered as resistance starch? Some people say inulin is not good for gut health. I have used it and found it lowered my blood sugar. However, later my gut health worsen. Some people says RS is good for gut health, but others say not. Not sure who to listen to.

  16. Bev says

    Hi ,so are you saying that if i put a green plantain (. Fresh)in a pancake or waffle mix , as im cooking it , it no longer is resistent starch?

  17. Johanne says

    Great article. Thanks. Will there be RS i fermented foods such as parsnip, jerusalem artichoke and onion? Or will the fermentation make the RS in these foods digestible?

  18. Perry says

    If these carbs can’t be digested, then how is it we are able to get its nutrients?

    Also, why is it they do indeed raise the glycemic load? Potatoes raises it quite a bit.

    Not that I am saying it is a bad thing, because that is what the body does, it is normal. I’m just saying.

    • todd says

      They can be digested, first by specific types of bacteria in the large intestine ( after passing thru small intestine) that convert them into a product processed by even smaller bacteria that convert it into butyrate, which heals the large intestine and provides energy to the cells.

    • David I says

      RS is not digestible to us, but it is digested by the bacteria that live in our intestines. In return, they secrete butyrate, which is essentially butterfat.

      True, you are eating ‘carbs’, but what actually gets into your bloodstream (well, actually, into your lymphatic system) has been transformed into fat.

      Cooked potatoes do indeed have a high glycemic index, but uncooked potato starch does not; things we can’t digest never have a high glycemic index.

      • Stephen says

        David (Or anyone),
        Do you have any idea about how many digestible carbs are in a small raw white potato? A 170g raw white potato is ~80% water (136g) and ~31g of carbohydrate. If there are 25g of resistant starch per 100g of raw potato*, then I would assume that raw potatoes have 0g digestible carbs. (136g+42.5g=178.5g) Which I guess would indicate either a difference in water or fewer than 25g RS per 100g?
        Am I right?


        • Tyrker says

          Yes, raw potatoes are essentially indigestible.

          Cooked potatoes have anywhere between 2 and 5 grams per 100g, and cooked-cooled potatoes have 5 to 10 grams, according to the FreeTheAnimal site.

          However, these figures are not necessarily verified.

          • Paleophil says

            Raw potatoes are digestible (for those whose microbiota, digestion and immune systems are robust enough to handle them). In addition to RS, raw potatoes contain digestible starch, protein and a small amount of sugars. Nutrition data reports that one small 170g raw potato with skin provides 131 calories, including 31g of digestible carbs: I occasionally eat a small, new raw potato or two.

            As was pointed out, the RS is converted into short chain fats, so it would probably make sense to count that as additional fat calories if one wanted to count every calorie and gram of macronutrient. I don’t know of any published source that counts those indirect calories from RS. Tatertot Tim Steele estimated that somewhere.

            Generally, I think it makes less sense in the long run for most people to count macronutrient grams and calories down to fine details than to try to eat a variety of healthy, whole ancestral foods (including those rich in prebiotics), which Chris Kresser often talks about. Probably the most important lesson of RS is to not chronically avoid all starchy foods completely if there isn’t an absolute medical necessity to do so.

  19. Sariah says

    This new information on RS has been very interesting for me to see. Through ally lay research on WAPF guidelines, paleo, GAPS, etc . I tend to lean towards the idea that traditional diets were in inherently healthiest as our cultures passed down through generations, ideas about what to eat and how to eat it. RS is a daily part of the diet in Benin and other countries in West Africa. These include Ablo–a fermented rice dumpling that is steamed in corn or banana leaves, pounded yam, gari (fermented dried cassava root), plaintain flour “fufu”, akassa, fermented rice flour.

  20. Santino says

    Maybe somebody can give me advice:

    I can not tolerate fermented foods because of histamine intolerance. So I take a probiotic.

    I suffer from a chronic procitits. At the beginning I felt little pain and had bloody stool, higher calprotectin. Through a Paleo diet (no gluten, low histamine, diary and egg free) I got rid of many symptoms like the bloody stool and most of the pain (was not much pain). But I still suffer from irregular motility and mood and energy swings which correlate with my bowel movements. This means:
    I am often constipated for 2-3 days. Then I have either normal motility like I always had (2-3 per day) or I have one movement per day. When having my old motility back, I feel good energy. But the most time I feel like a little subdepressive and low energy…

    When I had acute proctitis the first and only time, I could not tolerate anything but rice and potatoes. Sugar and diary gave me massive mood swings (anxiety). Had to eat rice and potatoes for a week with a probiotic to get normal again…

    Since I suffer from proctitis I cannot tolerate any Gluten, or FOODMAPS. Foodmaps give me heavy brainfog and constipation (tried inulin)

    I tried Bimuno (GOS) which my gut tolerated well, but I react allergic to it (I react to many things :-/)

    So I ask myself if could use Lactulose as a prebiotic for a longer time. Is this an good alternative to inulin or FOS?

    In my probiotic is FOS, but the bacteria eat it all up during the preactivation- phase (has to be diluted in water 25 minutes before drinking)

    Or should I start with tiny amounts of FOS?! But even a tiny capsule of Inulin gaves me heavy brain fog for days last time I tried it. I have no idea where to go with there issues. There´s no Chris Kresser in Germany…:-/

    Can anybody help me with this?

    • Gemma says


      Is chronic procitits related to IBS/IBD/UC like symptoms?

      These are often caused by yeast overgrowth elsewhere in the intestinal tract. Perhaps you might look at that, any chance to test it in Germany?

      There are various anti-fungal diets, you need to try and experiment, how to calm the inflammation down.

      Here a list of ideas and tips, not sure if and what would work for you, and if you search around you surely find some more.

      fats: olive oil, coconut oil
      food: garlic, onions, leeks, medicinal mushrooms
      prebiotics: beta glucans
      probiotic: Bifido, S. boulardii
      herbs: turmeric, milk thistle, ginger, propolis, echinacea

      Perhaps counter intuitive, but what about some honey.
      Get some honeydew honey from Schwarzwald :-) (Waldhonig, Honigtau)

      And recently I have heard someone healed similar symptoms eating a raw potato (one daily).

      You said you react badly to inulin but sometimes the bad reaction is needed for the healing to happen.

      This is just a quick summary, of course.

      Good luck.

      • Santino says

        Thank you!

        The symptoms were constipation, two times bloody stool. When first occuring I had diarrhe. But then fructose-intolerance was diagnosed with breath test (but not lactose)

        Stool analysed never showed any signs if any parasites and not yeast overgrowth was detectable. They looked into my colon but just saw an unspecific proctitis.

        After avoiding fructose (was gluten free before already) I got constipated.

        Now I dona ketogenic diet which makes me feel best (still feel low energy, bad mood etc, but I am much more stable than before).

        So the inflammation should not be the problem anymore. But the symptoms are still: 2-3 days constipated (normally I went toilet 2-3 times a day), then sometimes I have a normal day. Most times I feel good then.

        Tried Inulin–> heavy brain fog
        Bimuno–> allergy to one ingredient, but no brain fog with this GOS
        Inulin trouhh foodmap foods–> heavy brain fog

        My idea was to try lactulose as prebiotic (this is also a bifidogenic GOS with no additives).

        Maybe I am lucky and this makes my gut better over a few weeks?!

    • Heidi says

      @santino I’ve recently learned that certain strains of probiotic can increase histamine levels, which causes painful inflammation in some people. May be worth looking into.

    • Heather says

      How much magnesium do you think you’re gettinng? You need to make sure you’re getting plenty. I have had excellent results with tight, stiff, sore, kinked, cramping muscles from increasing magnesium intake at bedtime. Also drastically improved my digestion :) maybe not the perfect digestion routine, I’m stick hacking all that, but at least I’m not bloated constipated with all of the muscle aches anymore.

  21. Eva Nikolic says

    Is it counterproductive to take TCM herbs and RS and fibres at the same time? If I wish to build up my bifidos with RS and a good diet, could I decimate the bifidos with TCM herbs?

  22. Chris says

    Are Tigernuts RS2?

    I’m interested in finding out if the resistant starch in Tigernut Flour would turn into regular starch when I bake with it.

    @Tim Steele, you can find the most delicious Raw TigetNut Horchata at :)

    • Trilife says

      The link points to potato flour. You want to be looking for Kartoffelstärke. Biomarkt likely carries this.

    • Susanne Adegbite says

      Yes, it appears to be the same, I have written to them, because they name their product “potato flour”, but on the box it says that it is pure potato starch. Their answer confirmed that it is 100 % potato starch and NOT the flour from the whole potato. It is also an organically certified product (Bio). Greetings from Austria

      • jepps says

        Thank you, Susanne, for your answer. Is this the important difference, whether it is potato starch or potato flour?
        Bauck heats the potatoes to 30 degree, so the starch is raw and unmodified.
        Greetings from me from Austria, too, and good holidays to all! jepps

  23. Emily says

    I have a question as far as resistant starch and SIBO. I am always concerned to add in prebiotics, such as FOS, due to the prevalence of SIBO and not wanting to feed the bad bacteria. However, a lot of my patients would benefit from resistant starch as I often see low butyrate on stool studies. My question is if resistant starch will feed bad bacteria like prebiotics might.

  24. Darlena says

    I will begin an autoimmune Paleo diet in January and I am wondering if I can include a resistant starch into the protocol?

  25. says

    We are the first company to clinically test our resistant starch and we have the highest Resistant starch test. Companies are falsely stating the resistant starch as the total starch. Total starch of eg 70-80% is not resistant. Next year we hail our totally unique process that will deliver the purest resistant starch on the market in a pharmaceutical grade facility.

    • says

      If anyone is still interested/subscribed, I thought I would give a great update.

      Last year, a family of four created a crowd-funded experiment (using Indiegogo) to see the effect of RS on their gut microbiome.

      They each ate a different amount of raw potato starch daily (1-4TBS each) for six weeks, and had before-and-after gut microbiome testing.

      Bottom-line: All four had amazing increases in Bifidobacteria and other bacteria associated with a healthy gut and immune system.

      Family of Four RS Project Results

      Have a look! You’ll see all the proof you need that RS is good stuff.

  26. Kristi Vice says

    One more thing…….

    I am very sensitive to nightshades, and I can hardly move after a serving, I am so achy. Potato starch does not seem to bother me.

  27. Kristi Vice says

    Sorry about monopolizing the comments, here!

    I wanted to add that I started adding potato starch to my diet about two months ago. I have experienced great quality and dream-rich sleep. I get up less during the evening, when I do wake up for any reason I seem to be able to go back to sleep instantly, and I have aspired to a more ketogenic diet. I have read that he addition of resistant starch may lessen some of the problems people have on very low carb diets.

    After trying one tablespoon and having some gas, I started a plan beginning with one teaspoon of potato starch and adding another teaspoon until I reached two tablespoons. I drink it in a large glass of water first thing in the morning. I have not increased beyond 2 tablespoons, but I have added soil-based probiotics and some other fibres to my plan.

    I am reluctant to remove this as it has been noticeably beneficial! So many supplements that I have tried do not seem to make a noticeable impact.

  28. Kristi Vice says

    I want to add one more comment about my question of how to include potato starch in my diet.

    JJ Virgin lists potato starch as a high impact sugar grain. I joined her sugar impact plan and sent off an email asking about potato starch, but the reply that I received came from one of her staff members and basically recommended that I use one of JJ’s approved fibers.

    I did not believe any real thought went into the reply that I received; at least, I did not get an adequately descriptive reply why potato starch might be problematic for someone overweight who wished to lower sugar in his or her diet.

  29. Kristi Vice says

    I have been trying to learn how to decipher the nutrition label of Bob’s Red Mill Potato Starch. The label lists one tablespoon as containing 40 calories of energy, 10 grams of carbohydrate and 0 grams of fibre. If roughly 8 grams of the carbohydrate are in the form of a resistant starch when consumed at cold temperatures, can I assume the one tablespoon serving has an effective carbohydrate/sugar dose of 2 grams and an effective fibre content of 8 grams?

  30. Carol P says

    Chris, Do you happen to know whether beets have RS, either raw or after being cooked, then cooled? I notice it is not on the list of RS in foods that is included in the article by Murphy et al. Thanks!

  31. carri foss says

    Hi Chris, does the rice have to be parboiled? I don’t want to buy the pkg stuff so how does one make it’s own ? Is it as simple as just not cooking it till soft?

  32. George Jordan says

    Hey there,.. I would like to recommend durk and Sandy Shaws resistant starch flour as well as your potato starch. Find it at I’m using that every day and it works fine, very full after I have my shake. Best wishes to all my fellow dieters.

  33. susan stewart says

    Have been trying Resistant Starch for the past 6 weeks – primarily potato with green banana flour (WEDO) recently. Unfortunately, contrary to the information in this article plus comments, it causes blood sugar spikes in me – esp. the banana flour. I am not overweight, exercise regularly, and follow a low-mod. CHO diet: 1-2 fruits/d, no potatoes or root veggies/corn/grains/peas/winter squash, but lots of green veggies, goat yogurt, eggs, raw goat cheese, some tempeh & sprouted tofu. Although I am not a diabetic, I have 2 brothers who are (+my dad was) and I am trying to not become one. My blood sugar spikes out of my target range (75-120) if I am not very careful with the carbs so I know I am glucose intolerant/insulin resistant. The Resistant Starch has thrown me a bit out of whack – hopefully, I will be able to re-stabilize.

    • Cyro says

      You need to test yourself if the resistant starch is resistant indeed. Use your glucose meter. Measure pre-prandial blood glucose level, eat 30 grams ou 1 Oz of carboidrate and measure again your blood glucose level after 30, 60, 90 and 120 minutes. Compare the results with comon hi carb foods and other supposed resistent starch foods. Adopt the ones you find more resistent (that makes your blood sugar levels rise less). Green bananas (that don’t have any sweet taste) are for sure resistant starch, but I don’t know if it’s hard to find. Ammina potato starch the paleo comunity say is ok too, and there is others.

  34. jepps says

    Does anybody know that:
    Potatoe starch consists of 80% starch, 75% of this starch is resistant. And what is with the rest? Is the rest starch, which counts for starch consumation, and therefore for carb calories?

  35. says

    Regarding Jill’s question, above, concerning GAPS-type diets that restrict most starches and sugar…and when it might be useful for gut-healing to reintroduce foods containing these things:

    I unfortunately don’t have answers, but I have a lot of thoughts on the topic and have written many of them down here – . I also think that Tim is right, in that there is unfortunately no magic prescription for gut-healing…and you might not know how a certain diet is going to affect you until you’ve tried it for months or years.

  36. says

    One thing I am noticing, as I continue along this gut-healing path (4.5 years and counting), is that many things (like resistant starch) have produced “overnight results.” But the _results over time_ are those most difficult to wait for, and most relevant.

    I began re-introducing starches (both resistant and absorb-able) eight months ago. The effects were instantaneous and kind of like a mad see-saw, to put it mildly. It was amazing! For three and a half weeks. Then…I suddenly sank as low as I’d ever been. It was really bad for over a month. Now…a more gradual climb back up… Months later, I am tentatively hopeful, really grateful, and still climbing.

    I am more hesitant than ever to draw conclusions, but I am hoping against hope that long-term stability and better health will be the eventual result of years of tinkering with, changing up, adjusting, obsessing over, and analyzing my diet.

    Therapeutic protocols are an important tool; now, I am hoping that RS foods are more of an in-it-for-the-very-long-haul sort of deal.

    Thanks so much for bringing more and more attention to these topics in articles like this – and Tim, I appreciate your show-don’t-tell helpfulness, providing hope of stability and health to many.

    Maybe I’ll get over my fear of the Evil Eye and post an update on my own health soon. :) For now, I’ve put some of my thoughts (concerning RS and diet) here:


    • Gemma says


      I have read your blog. If only more people were able to think deeply like this and tried to connect possible dots.

      Just wondering now, as I have noticed you read Dr. Grace as well, so you must be familiar with her WEED SEED FEED motto.

      What do you do for the WEEDING part?

      • says

        For the “weeding” part? Well, I pray! No really, I have not implemented anything in particular for us in this department, although I’ve dabbled with charcoal and clay and various other “detoxifying” things. But I’ve never been clear on when and what, exactly, is warranted…

        • Gemma says


          I think you and your family would benefit a lot from more “weeding”. Feeding is not enough.

          It would be good to take a gut test, to see what you are fighting, and react accordingly.

    • Gemma says


      by the way, I hate going groceries and vacuuming. But it feels good to have it done and see the results. The pantry and the fridge are full, and the floor clean. For a couple of days, at least :-)

      And, it feels good to be alive, too.

      Eat. Sleep. Laugh. Love. Repeat.

      if I can do it, then so can you.

  37. George Ingram says

    I find it absolutely bizarre the cold potatoes are a digestive resistant starch!. Is this really true? Why have I never heard this before? This means that cold potatoes could be on any type of diet, even low-calorie. This has never been said anywhere that I have ever seen.

    • says

      They’re not 100% resistant starch, so they’ll still contain calories and carbohydrates. But that doesn’t make them inappropriate for most diets except ketogenic and maybe autoimmune if nightshades are an issue.

  38. Nikko says

    Do sweet potatoes fall under the cooked and cooled potatoes category, and how should the right potatoes be cooked in the first place?

  39. Gemma says

    I would like to add a point here, Duck. You are right that pH is the key to the Candida’s virulence, but not the only one. It is a hungry yeastie beastie…

    There might be specific circumstances when it becomes virulent despite the right pH, see this paper:

    The Fungal Pathogen Candida albicans Autoinduces Hyphal Morphogenesis by Raising Extracellular pH

    “pH homeostasis is critical for all organisms; in the fungal pathogen Candida albicans, pH adaptation is critical for virulence in distinct host niches. We demonstrate that beyond adaptation, C. albicans actively neutralizes the environment from either acidic or alkaline pHs. Under acidic conditions, this species can raise the pH from 4 to >7 in less than 12 h, resulting in autoinduction of the yeast-hyphal transition, a critical virulence trait.

    Extracellular alkalinization has been reported to occur in several fungal species, but under the specific conditions that we describe, the phenomenon is more rapid than previously observed. Alkalinization is linked to carbon deprivation, as it occurs in glucose-poor media and requires exogenous amino acids. These conditions are similar to those predicted to exist inside phagocytic cells, and we find a strong correlation between the use of amino acids as a cellular carbon source and the degree of alkalinization.

    Genetic and genomic approaches indicate an emphasis on amino acid uptake and catabolism in alkalinizing cells. Mutations in four genes, STP2, a transcription factor regulating amino acid permeases, ACH1 (acetyl-coenzyme A [acetyl-CoA] hydrolase), DUR1,2 (urea amidolyase), and ATO5, a putative ammonia transporter, abolish or delay neutralization. The pH changes are the result of the extrusion of ammonia, as observed in other fungi.

    We propose that nutrient-deprived C. albicans cells catabolize amino acids as a carbon source, excreting the amino nitrogen as ammonia to raise environmental pH and stimulate morphogenesis, thus directly contributing to pathogenesis.”

    • Duck Dodgers says

      Great find, Gemma!

      So, it sounds like Candida will stay benign as long as we keep it happy, by feeding it moderate levels of glucose (and keeping the gut pH normalized). If we starve it of glucose, it automatically changes its own pH so that it can become hyphal to search for tissues to feed on.

      Interestingly, conventional “candida diets” choose to starve candida with zero carb diets. However, candida can metabolize ketones (after an adaptation period) and will actually grow exponentially when starved. Here’s a great quote from Gestalt (who uses RS to normalize gut pH against candida):

      From: How to eliminate Candida & biofilms

      It is the conventional belief out there that to get rid of candida one must consume little to no carbs in order to stop their growth. This logically means putting the body into ketosis. What most people don’t know however is that ketones can also fuel candida growth and the fungi themselves use ketones to evade the bodies immune system. The following is the collection of a few days research that completely shifts the conventional paradigm on the various forms of Candida diet out there.

      The following 1st paper shows that the ketone beta-hydroxybutyrate will feed candida, and the 2nd shows that the ketone Aceoacetate is used by Candida to evade the body’s immune system. The 3rd shows that starvation makes candida grow exponentially.

      “The ability to neutrophils from diabetics to kill candida was inhibited by increased concentrations of glucose and beta-hydroxybutyrate, both independently and in combination.
      These data indicate that although phagocytosis occurs at similar levels in diabetics and controls, killing of candida by the diabetic neutrophil is impaired under conditions of hyperglycaemia and ketosis.” (reference)

      “Therefore, prolonged ketosis may be a significant risk factor for candidiasis. This study was undertaken to investigate whether C. albicans itself produces a ketotic metabolite as a virulence factor which can effectively undermine host defense by neutrophils.” (source)

      Starvation of yeast cells induces exponentially grown cells (and usually non-germinative) to germinate. This phenomenon is also observed in cells that are transiently treated with metabolic inhibitors. During each of these treatments (starvation, metabolic inhibition), expression of a growth regulatory gene (CGRI) increases. Candida albicans: adherence, signaling and virulence.” Calderone et al.

      Glucose obviously feeds candida as well however I have not seen evidence that it impairs immunity against candida such as ketones. Glucose therefore appears to be the lesser of two evils in this case when compared to ketones. From a blood point of view it’s impossible to eliminate glucose anyways. Ketogenic diets and many Paleo diets therefore in the long term are counter-productive. Starch and specifically resistant starch is necessary to feed the good guys which are your primary defense against candida.

      • Gemma says

        Great summary and thoughts, Duck.

        The human body is used to overnight fast or occasional hunger, or therapeutic fasts as practiced in some religious communities (long-time tested and refined to perfection).

        And we know that the proponents of ketogenic diets promoted supplementing with SuperStarch (contains 67% resistant starch).

        Do people playing with the long-term ketogenic diets know all this?

        • says

          You guys always amaze me! I am smelling a change in the air. Check out these two blogs from today:

          Chris Kresser, Is Low Carb Diet Ruining Your Health?


          Tom Naughton, questioning the rationale of ketogenic diets:

          I am seeing a huge shift towards gut health from people who have been staunch supporters of low carb dieting.

          • says

            The problem here is common with various other health/food topics. A broad generalization and labeling of a nutrient/substance and treating all forms as if they are one thing when in fact the body metabolises them so differently that it is erroneous to call them the same thing. So… “carbohydrate” is a gross simplification and as such a “low carb” diet is also. We need to do away with the term “carbs”. As most of you (here) know, better to be low-carbage (garbage carbs) yet high-carbiotic (prebiotic carbs). And y’all know how to do this in a “clean” way… Caveman style undercooked tubers, soaked/sprouted and cooked-n-cooled grains/seeds/legumes, etc.

            I personally prefer undercooking tubers. It’s easier and I’m lazy 😉

            What we need is a carbage-free world 😉

    • Tim says

      Molly – I think the problem is that Candida can wear several hats, and even go ‘underground.’ In a healthy biome, Candida can be part of the normal flora and cause no problems, but when something goes wrong it can take over. It’s when it is in the hypergrowth phase that it will eat RS and make itself stronger.

      If you have, or suspect a Candida overgrowth problem, it’s best to deal with that first before going heavy into RS.

      • Duck Dodgers says

        Technically RS could feed candida. However, this may not be an issue if RS helps to normalize your gut pH.

        The key here is that Candida is only hyphal when it gut pH is too acidic or too alkaline.

        Alkalinity promotes Candida overgrowth

        If you read through the studies in that link, you’ll see that Candida has a number of growth genes that are sensitive to pH. These hyphal growth genes switch on when gut pH is too high or too low.

        Candida is a dimorphic fungus, which means that it can be either benign or pathogenic. I suspect it evolved to live symbiotically with hosts until the hosts dies which then causes pH to become abnormal — so its pH sensing mechanism then knows becomes hyphal to help decompose the corpse upon death. We just probably confuse it when we mess up our guts and it appears to turn on us. It probably just thinks we are dead or dying and goes to work recycling us!

        Anyhow, most people — particularly those on a very low carb diet — have guts that aren’t fermenting and are therefore too alkaline, which as we can see from above promotes candida overgrowth. For these people, taking RS will increase SCFA (acid) production, which helps normalize gut pH and switch off the candida growth genes — returning candida to its benign and harmless state. Interestingly, there are plenty of studies showing that acids and SCFAs either inactivate or kill candida. Simultaneously, RS tends to bloom good bacteria (which also contributes to increased SCFA production), which will crowd out candida. It’s also a good idea to use a candida biofilm disruptor so that good bacteria can move in to candida’s territory.

        In somewhat more rare situations, people can have guts that are too acidic — as sometimes happens with people with ulcerative colitis, for instance. In that case, RS might be problematic for those individuals since its SCFA metabolites might not directly help raise gut pH. Experimentation would be needed for those people.

        For those interested in using RS to combat candida, I highly recommend reading this article:

        How to eliminate Candida & biofilms

        The author of that article was able to eliminate candida in less than 1 month using that approach.

        Good luck!

  40. Drini says

    Hi Tim, I have a question for you! How do you feel about alcohol? Do you personally drink? Would it be a good idea to stay clear of alcohol while trying to creat a better gut environment with SBOs and prebiotic fibers, in you opinion? Thank you!

    • Tim says

      I drink on rare occasions, maybe having a drink or two a couple times a year.

      I make homemade beer and like to tell myself the layer of yeast on the bottom of the bottles is good for me. I’ll drink a bottle of this medicinal ale once a month or so.

      I used to drink excessively, nothing positive ever came from that. I haven’t been ‘drunk’ in 4 or 5 years.

      I think a glass of wine or some beer is OK, maybe even daily, but any more than that probably starts to have negative impact on gut health. Fermented fruits and grains have been alongside humans forever and certainly have healthful qualities at some level and not-so-healthful in excess.

      • BrazilBrad says

        Side note. Been reading a bit lately about the ancient Egyptians. I read that many (most?) drank quite a lot of a weak grain fermented beer due to the safety of it. It was supposedly safer to drink than water because of less dangerous bacteria due to the fermentation. I assume since it was “weak” it had less of the alcohol buzz. My interpretation was they drank it for health, not the buzz. I’m sure more like your home made brew Tim. Their main grains were Emmer wheat and barley.
        Strange that they didn’t just boil water to purify it. So maybe they were drinking the beer for the buzz ;-). Or some other reason? Like too much trouble or costly in time/effort or fuel source (or due to the heat) to bother with boiling the water?

  41. Tim says

    These comments are getting too long! Do a ‘Ctrl-f’ search for Hi-Maize, I made a bunch of comments up above about my feelings towards it.

    It’s not bad, per se. Lots of people using it, and lots of studies conducted with it. Just be aware there are several versions and some unanswered questions.

  42. Kenn says

    Amy and/or Tim, can you please explain why Hi-Maize RS4 corn starch is “not recommended?” I’ve seen clinical studies that showed great success using Hi-Maize. The only mention of it on Nikoley’s blog is that he wasn’t going to try it because of his “paleo leanings.” Rice and legumes aren’t paleo either, though, so I don’t understand this.

    Is it because it’s synthetic, because of grain lectins, because it’s GMO corn, or something else? Is there a potential for harm using high-RS corn starch, or is it simply unnecessary when you’re consuming plenty of RS2 and RS3?

    I’ve got 5 lbs. of Hi-Maize in my kitchen. Should I throw it out?

    Thanks for your insights on this.

  43. Larry Eshelman says

    Chicory root is a good source of inulin and FOS. How good a source is roasted chicory root? Does roasting destroy a lot of the fiber? I’ve searched the web, but can’t find any numbers on roasted chicory root. I’ve been adding a couple of table spoons of roasted chicory root to my yogurt, along with potato starch. I like the taste, but I don’t know if I’m getting any fiber benefit from the chicory.

    • Tim says

      I read somewhere along the line that inulin and FOS are heat sensitive. You are probably losing some of the prebiotic qualities, but I think roasted chicory is an excellent food item to cycle into an otherwise fiber-filled diet. Roasting probably unlocks a few other things that are unavailable raw.

      Do you have dandelions in your yard? Eat them. Root and all. They are best in spring when they first appear and get bitter this time of year, though.

  44. Dave says

    How does RS compare or contrast to konjac-glucomannan? I seem to remember an MD writing about its ability to do the same thing as RS. Any info on this would be a big help. Thanks

    • says

      Dave – I think glucomannan is just as good as RS and inulin as a ‘foundational’ fiber. The only problems is that it is fairly limited to only a few foods (konjac mainly) and the supplement form is extremely absorbent. It doesn’t mix well with anything as it turns into rubber if mixed too strongly, posing a real choking threat. If you buy some glucomannan powder, please mix it with water and wait 5-10 minutes to see what I mean. If you use it, and I have, drink plenty of water 8-16oz, alongside it.

      Konjac noodles are great, though!

  45. Michael says

    Very interesting article. Any idea how long it takes to feel the effects of the increased butyrate production, assuming you’re eating 15-20 grams of RS per day?

    • says


      The results for BG control and sleep usually happen the first time you try it. Some of the other benefits may take a bit longer, and if you have a terribly dysbiotic gut you may not see benefits at all.

      The gas associated usually goes away in a few weeks as your gut flora composition changes to use all the byproducts of the RS fermentation.

      Start with a small dose, 1tsp – 1TBS, and work your way up. I don’t think there’s a need to go over 2TBS if you are also eating lots of the food discussed here.

      • Michael says

        Thanks, Tim. You mentioned that if you get a lot of digestive discomfort it’s a sign of an unhealthy gut. Can we assume that the reverse is also true, i.e., no digestive disruption = healthy gut? I’ve been eating a whole raw Russet potato now for three days in a row. I cut it up and have it with olive oil, salt, and pepper – it’s not bad! No digestive issues so far.

        • Tim says

          If you can eat raw potatoes, you most likely have a pretty solid set of gut bugs. Glad to hear it!

          You should see if you can find Jerusalem artichokes and try those raw. I’ll be curious how you do with inulin.

          I like raw potatoes as you described. Vinegar gives them a nice kick, too.

          • Michael says

            I’ll look for them! I’m blessed to live three blocks from an excellent natural foods co-op. One final question, about potato flour. The brand I have (Ener-G) lists the ingredients as “pure potato starch.” But you’re saying potato flour and potato starch are not the same thing? Is there a reason to avoid potato flour if you’re not eating it for the RS? For example, as an alternative to gluten-containing flours?

            • Tim says

              If it says ‘pure potato starch’ it should be OK to use. Check to see that it settles to the bottom in a glass of cold water.

              Potato flour is whole, ground, dried potatoes. Potato starch is the extracted starch…big difference. Sometimes I guess they use the terms interchangeably, but incorrectly.

              Potato flour is fine for certain applications, ie. GF baking

      • says

        I somehow missed the explanations as to why or how RS improves sleep. I’ve definitely noticed myself sleeping better since I’ve been using it, but I have patients with very stubborn insomnia, and I’m considering recommending RS, but would like to have a better sense of how it works for sleep. Thanks in advance!

  46. Diana Durnford says

    Do any of you have any advice on RS for Lyme patients?

    How about on RS for a combination of Lyme, SIBO, dysbiosis and myriad of other infections all combined?

    Thank you to all of you who are sharing your invaluable advice.

    • Duck Dodgers says

      I’m aware of some CFS patients who tried supplemental Resistant Starch. You can read about their experiences here.

      Some of the experiences were good. Some were bad. They are a tricky bunch as they tend to have trouble clearing endotoxins as pathogens get killed off. And this tends to result in inflammation. Sort of like taking a step back every time they take a step forward.

      Some of them had more success with Larch Arabinogalatan (LAG), which is an immune-stimulating fiber that requires relatively tiny doses to have a big effect.

          • Debbie says

            So, does the prebiogen have stuff lacking the PS? In other words, would the average person with some gut issues benefit from this product when cheap PS works just as well?

            • Duck Dodgers says

              Prebiogen feeds different species and does different things than PS. You can consider PS to be one of the staple foods of your microbiota (literally the rice and potatoes of your gut bugs). Your gut bugs can eat a lot of them too.

              Prebiogen contains Larch Arabinogalatan (LAG) and beta glucans, both of which have immune-stimulating effects in very tiny quantities. You typically only take a teaspoon or so of those immune-stimulating fibers — but they aren’t intended to feed your entire microbiota.

    • says

      No specific advice, but I think the current rise of Lyme disease is more a statement of our guts than an increase in ticks.

      Get a good gut and avoid Lyme disease. I read recently the Lyme disease causing bacteria, Borrelia burgdorferi, has been around for billions of years, but we’ve only recently been having problems with it.

      • Diana Durnford says

        So if you get your gut back in shape, are you then able to handle an existing Lyme infection, or by then is it too late?

        Is this too off topic?? I wondered if Lyme was similar to other gut pathogens that the body starts to manage well once gut health is restored, or if Lyme is somehow more resilient.


  47. Kari says

    So I just started experimenting with fermented foods. I added raw potatoes to my kimchi. They turned out great…. and nice and soft. So would that be an extra dose of prebiotics? How does fermenting potatoes fit in with this article?

    • says

      I’m inclined to believe that fermenting potatoes reduces the RS, but, I also think that fermenting potatoes is a very healthful way to eat them. They are still full of great fiber, some RS, and probiotics.

      Keep on doing it!

  48. Cheryl says

    Just to confirm . . .
    If I make bread with potato starch in it, and then keep it in the fridge overnight, the RS amount that was “baked out” will “return,” yes?

    • Tim Steele says

      Not quite that simple. Let’s say your bread recipe calls for 1 cup of potato starch, which weighs 200g (trust me, I just weighed a cup!).

      This 200g of PS has approximately 140g of RS (RS type 2). When you cook with it, it completely disappears, but allow it to cool and it will ‘retrograde’ into RS type 3, but at a much smaller amount. The 200g of PS will provide maybe 10-20g of RS3.

      If that makes a loaf of bread with 10 slices, each slice will have 1-2g of RS.

      If you are doing this JUST to get RS, it’s not a great plan. If you do it anyways, the RS is a bonus.

      Hope that helps!

  49. says

    Using this info regarding resistant starch (from the awesome article) can I let my children have a daily greenish banana to ensure they’re getting their resistant starch? I’ve avoided this thus far as we’re on the GAPS as my son on high dose steroids for nephrotic syndrome (auto-immune disease?) Look forward to receiving some insight!
    P.s my husband and I had our first teaspoon if green banana flour this AM!

      • Paleophil says

        My understanding is that bananas are not indigenous to Africa (nor the Middle East or Europe) and thus have not been consumed for millions of years, but “false banana” trees are, and the RS-rich pulp of the false banana trees, rather than the fruits, are favored.

  50. Debora says

    So I understood, we should eat plantain flour, potato starch, and green banana flour raw? Like making pancakes out of that won’t work? Unless we cook it under 130 degres?

  51. Tuber says


    Your information here is invaluable. Thank you!

    I have two questions I hope you can help me with. First, do different sources of resistant starch influence/feed different strains of friendly microbes? And if so, would it not be better to regularly consume RS from a variety of sources? I understand the convenience of potato starch and I use it myself; but does it feed only a few strains of probiotics?

    Second question: is it best to take probiotics with food or on an empty stomach? I have seen it argued that the stomach is actually less acidic during a meal when food is present than in the very acidic environment of am empty stomach. What is the truth here?

    • says

      Yes, different RS sources feed different sets of gut bugs so it is important, as you say, to eat more than just potato starch for your fiber needs. It seems in nature, the two biggest sources of fermentable fiber are inulin and RS2. These are not normally found together in nature in a plant or even geographically, but they feed a similar set of microbes when ingested. The microbes that ferment inulin and RS produce butyrate in copious amounts, but also leave behind scraps of the fiber for other microbes to eat. This is known as the ‘keystone and co-feeder’ effect.

      Other fiber types are equally important, but found in much smaller quantities in nature. This is why it is ridiculous to rely in wheat chaff, psyllium husk or oat bran as Metamucil would have you believe.

      Anytime you see a study produced by Metamucil… question it!

      The other fibers, ie. gums, mucilages, pectin, beta-glucans, arabinogalactins, FOS, GOS, etc… are ALL important and should be consumed near daily by including a wide range of fruits, vegetables, nuts, and seeds in your diet. Bee pollen is also a great source of fiber. Consuming these ‘other fibers’ in a real-food setting also allows you to consume numerous micronutrients not available in a supplement, just as eating potatoes gets you the goodies not found in potato starch. Fiber supplements are great to boost intake, but a poor choice for all of your fiber needs.

      Timing: How could you go wrong taking probiotics with a meal? That’s when they would have been consumed for millions of years. Also, take your RS supplement at the same time. Probiotic microbes can actually cling to the RS granules and get a protected ride through the small intestine. I’m always a fan of simulating natural, ancestral feeding patterns.

  52. Melina says

    Hi tim
    I have another question about tapioca starch. I just notice that my bag of Bob’s red mill tapioca says: “Tapioca flour also known as tapioca starch (and then it goes on on describing the process) is ground to a powdery fine granulation from the dried roots of the cassava plant”. You explained the difference between potato flour and starch. does that apply to tapioca as well? They seem to think that Tapioca flour and starch are the same. What are your thoughts on this?

    • says

      Tapioca starch is just so all over the place I have a hard time recommending it. The papers all say it should have great RS, but there are also different manufacturing processes that may destroy in in some brands. Until more is known, I just have to say, ‘try it’ and see what you think. Some swear by it, some say it spikes blood sugar.

    • says

      I am at a bit of a loss on tapioca starch. In theory, it should be b\very high (40-60%) in RS, on par with potato starch, but there are different processing methods some of which are said to destroy nearly all of the RS. Until someone markets tapioca starch that is labelled with the RS content you are taking a gamble. If you are doing it for glucose control and have a BG monitor, it’s easy to check. If you are just using it for general health and its your sole source of RS, you may be doing yourself a disservice.

  53. Natella says

    I am on low carb diet. What if I eat a small peace of potato raw or unripen banana small portion ? Will it have any usable carbs? Will it give me the resistant starch I need? Is Prebiotic the same as thing as resistant starch? Is the resistant starch the same as non soluble fiber? Thank you

    • Tim says

      Raw potato and green bananas have negligible net carbs and a great RS content.

      RS is a prebiotic, but not all prebiotics are RS.

      RS is a form of non-soluble fiber.

  54. Denise Baxter says

    I have found that using resistant starch, in the form of potato starch, has cause leg cramps to disappear. This occurred within the first week of taking it and worked when nothing else did, including using diet and minerals.

  55. Magdaly says

    I don’t know if someone can explain about my symptoms with RS.

    I was buying green plantain and drying them on the dehydrator and I was eating before meals and in the evening with the probiotics that Richard recommend.

    I was feeling tired, sleepy nearly every day for a few weeks, then one day I decided to stop taking them and my energy came back again I was surprised. The other night I have 1 tsp with my probiotics and 1 tsp with my breakfast and all my symptoms came back again feeling tired, without energy

    So I don’t understand how RS can work for someone with blood sugar problems when it really was causing the symptoms that I was trying to treat?

    • Paleophil says

      All I can tell you is that my blood glucose numbers improved significantly after I started consuming more resistant starch. The only way to tell for sure what effect you get is to measure with a glucometer.

  56. Melina says

    I’m not sure if you have answered this already. I like to add tapioca starch to my warm cup of chicken broth in the am. What is the max temperature that the RS in tapioca can tolerate?

  57. jake3_14 says

    It’s my understanding that psyllium seed is the prebiotic fiber, whereas psyllium seed husk is insoluble fiber that actually damages the lining of the small intestine, forcing a repair, during which the intestine secretes extra liquid, which moves food along. Am I missing something?

  58. Debbie says

    Do we know if there are specific bacteria that affect colonic motility? And if we do – is there a probiotic that contains it?

  59. KORINNA LEACH says

    Hi, I am on natural dessicated thyroid for my throid issues and also on the Paleo diet in order to keep Blastocystis hominus in control.
    As much as I am disciplined, I seem to be gaining weight, feel tired, crave caffein and find life a challenge still. I take Diotimaceus Earth, vitamins, and a mixture of ground flaxseed, psyllium fibre and chia seeds with my high probiotic yogurt each morning. Will this help with the resistant starch concept?
    I feel that I am losing my battles.

    • Energy! says

      You may need more thyroid and/or an adjustment in dosing such as taking 2/3 in the morning and 1/3 later in the day. The web site stopthethyroidmadness has many patient experiences with NDT if you haven’t visited it yet. If you’re still eating wheat, try avoiding it for at least a month because it can cause fatigue, at least for me.

      The flaxseed and chia seed would not be a significant source of RS as far as I know. I started with 1 teaspoon of potato starch in water and gradually worked up to about 2-4 tablespoons/day or the equivalent in mung bean starch, green banana flour, cooked/cooled potatoes, cooled white rice, green bananas, or green plantains.

      The combination of eating a primal/Perfect Health Diet, taking desiccated thyroid, eating zero wheat and resistant starch + other fibers and probioitics (including soil-based) has gotten rid of my decades-long fatigue, brain fog, and weight gain. It’s so worth figuring out what works for you. Good luck!

  60. Cate says

    Im curious as to how much RS is in the following:
    1) raw oats soaked overnight in homemade almond milk
    2) homemade peanut butter made only with roasted/unsalted peanuts

  61. DK says

    This is a great discussion and lots of good ideas being shared. I’m just wondering from a paleo purist point of view, aren’t potatoes a no no? Also the carb content of potatoes is very high so it could totally blow out someone’s weight loss plan?
    Happy to hear the experts’ opinion.

    • says

      A potato is a real food item, eaten by people of the Americas in the paleolithic. You’d be surprised how many potatoes it takes to make 100g of carbs. One smallish, potato (200g) has about 37g of carbs. Undercook it to where it is still a bit raw in the center and the net carb count drops significantly.

    • says

      Banana Flour…there are a few on Amazon and at WeDo Gluten Free. This is a great source of RS when eaten raw, and also makes really good gluten free pancakes and other stuff if you are into that.

      The RS content of banana flour is hard to pin down because of manufacturing differences, banana species differences and ripeness, but it will fall into the 25-50% range, which is pretty good. Lots of other good stuff, too, as banana flour is made from whole, dried bananas.

  62. Allison says

    Any idea if RS can suppress some beneficial bacteria like beneficial forms of e coli? I have to avoid FOS because it can suppress e coli (my levels of beneficial e coli are very low) so I want to avoid the same issue with RS. Does anyone know?

    I have been using raw potato starch and green banana flour (here in AUS) and seemed to lose some weight – yay :)

    • says

      I think you are getting some bad advice. FOS is a prebiotic just like RS and all the others. It serves mainly as food for bifidobacteria and lactobacillus when they are present. Flourishing colonies of lacto and bifido will suppress e.coli to some extent, but I wouldn’t withhold food from lacto and bifido to allow more e.coli to grow. That just seems like bad advice.

      The e.coli you have that will be considered ‘good’ is a small niche that finds a small foothold alongside beneficial bacteria. E.coli can easily turn pathogenic and can really thrive in a gut with high pH and low lactic acid levels. E.coli can survive a wide range of gut conditions, but will take over if gut diversity is poor.

      I’m not a huge fan of FOS, so avoiding it is no problem, but don’t avoid all prebiotics just to grow e.coli. Set the stage by eating good food, prebiotics, probiotics, and living a gut-bug friendly lifestyle. The microbes will sort themselves out.

      • Allison says

        Tim the advice to avoid inulin to prevent suppression of E coli is from Bioscreen who are a stool testing lab in Australia run by very experienced microbiologists. Their advice may be right, my levels of E coli dropped after faecal transplants and I was taking inulin after the faecal transplants along with other prebiotics incl.RS.

        I’m definitely not avoiding all prebiotics, just inulin. I am taking lactulose, some GOS occasionally plus RS in food.


  63. Laurie says

    I tried Bob’s Red Mill potato starch twice, for a couple of weeks each time with a break in between. Both times I was ravenously hungry all day which is not normal for me since going paleo a couple of years ago. I’m not diabetic and did not think to check blood sugar at the time and haven’t used it since because I hate feeling so hungry! My diet did not change so I can’t attribute the increased hunger to anything but the potato starch. I started with 1/4t and worked up to nearly 1t before I quit it altogether. Read the comments about anxiety and RS and although I didn’t feel anxious, I wonder if you’ve heard of this hunger reaction with potato starch?

    • Allison says

      I had a subjective feeling of low blood sugar when I initially used potato starch, but that problem seems to have resolved now. I’m not sure why it was happening, perhaps adrenal issues.

  64. says

    Great topic, terrific info – thanks all, Amy, Chris, and TIm. I’ve been looking for a detailed resource on RS for myself and my patients. This fits the bill! I’m thinking, Chris, that Amy, Tim and yourself talking in detail about RS would be a great podcast – though it would probably need to be an hour long show to do the topic justice. Thanks again!

  65. Debbie says

    I’d like to share that I’ve been eating about 4 tablespoons of PS daily. I’m not sure how much it’s helped me. The old constipation is better, but it’s still not a daily thing. I have a few SBO probiotics daily too, and am eating sweet potato and kombucha squash daily. I still don’t remember my dreams. I hesitate to say this – because I’m not sure if I’m imagining it, or it’s due to age or whatever – but I do seem calmer within, less apt to flip out. But, I don’t know if that’s due to improvement in my gut bacteria population. I’d like to think so. It would be so incredibly empowering and hopeful. So, that’s my update.

  66. Melina says

    Tim this question was addressed to Chris but you are the one answering. Do you have any coments? or maybe Amy?

    Hi Chris. I’ve been following the topic of resistant starch for a while now and experimenting with it. I have read all your posts about it and other people’s as well. I have Hashimoto’s and I’m currently doing the autoinmune protocol. Most of my symptoms are gone except constipation. I can not do potatoes during the AIP. So I read that casava also have a hig amount of RS and added to my diet in the form of tapioca starch. To my surprise it relieved my constipation almost right away with only 1 Tsp. Then in one of your potcasts you said that casava has very high amounts of goitogens and coking will decrease them. But cooking will damage the resistante starch. So I’m a little lost here. Can you please coment on this? Thanks a lot.

    • says

      I see mixed results on whether cassava is a goitrogen, see:

      But it could be, see:

      But generally when a starch is extracted, nearly all of the toxic compounds are removed along with the plant proteins. I can’t say 100% positively that tapioca (cassava starch) is non-goitrogenic, so you’ll have to weigh the danger in your own mind. To me, it’s not worth worrying about. Use it if it helps your constipation.

      Until someone markets a tapioca starch that has been fully tested for anti-nutrients and RS content, it’s all faith-based, but tapioca starch in the studies has very high RS.

    • Chris Kresser says

      I’d agree with Tim on this. In most cases, the extracted starch is low in residual toxins because the toxins are in the plant proteins. Eating whole cassava/manioc/yuca raw prior to boiling it is probably not a great idea, but eating the starch—especially in the amounts you’re talking about—is almost certainly benign.

      • Melina says

        Thank you so much Chris! This helps a lot. taking my health in my own hands is a big wild experiment. thanks for being such a great guide!

  67. Ricky H. says

    This is just a bit off topic but I would love to hear any advice. My situation is this:

    – 44 year old, 5’11 and 225 pound male. Very active with tennis 4-6 times a week.

    – severe acid refulx and have been taking prilosec once daily for ten years.

    – numbness in feet and more recently hands. I’ve had blood tests for B12 and levels were 1200 plus. Can’t figure out the numbness, had MRI, am not diabetic, all blood work is normal.

    – I know that the Prilosec is a bad thing to take long term but I am having an extremely hard time doing without it. Tried apple cider vinegar, Zantac and Paleo with major reflux pain after a couple days.

    Very frustrated. Any thoughts?

    • John Es says

      I had very similar symptoms.

      The GERD went away on a very strict Cordain-style Paleo diet (no salt, no dairy, very lean meats), but, came back severely. This is a very complicated issue, and there is a lot of individual variability, IMO. So, no good general advice. I believe I may have gone too low carb, which was stressful, and might have starved bacteria to a fault. Stress was certainly a factor (brain/gut axis). Also, vlc maybe furthered hypothyroidism, which weakened gut motility, causing mild SIBO. My most noticeable improvement came from supplementing with betaine HCl. Now, I follow a fattier Paleo diet, with plenty of salt, both broth, organ meats, and a variety of vegetables, slowly making progress. I still have some GERD and LPR, but, my main digestive symptom is now mild IBS. I’d like to get a Biohealth 401H to see where I’m at with regard to gut pathogens and dysbiosis. My Doctor’s Data Comprehensive Stool Analysis came back fairly clean, just a little dysbiosis.

      I have had better results with the numbness. Blood work might not be sufficient to detect issues with blood sugar metabolism. My Dr. looked at my (very low) fasting blood glucose, and didn’t pursue that angle (but, who knows if he was even *listening* regarding the numbness). I recently had an HbA1c, and it was on the high end of the range. I’m going to start testing postprandial blood glucose after lunch for a week or two. Over all, my numbness has steadily improved after nearly two years of Paleo. I’m inclined to attribute it to the blood glucose stability that comes from avoiding sugar and grain, and eating more fat.

      PPIs stopped working for me, so, it wasn’t hard to give them up. Common advice is to wean off, and maybe transition to an H2 receptor antagonist to smooth out the PPI rebound effect.

      The incidental side effect of eating Paleo was the loss of about 40 lbs. I never imagined weighing so little, but, it seems like a healthy weight.

      I’m planning to work with functional medicine practitioner, probably somebody trained by Reed Davis, but, I wish there were more Kalish practitioners.

    • Energy! says

      My hubby had tingling toes at times plus sporadic awful calf cramps for years. He also had GERD. He never had diabetic symptoms but had multiple food sensitivities.

      First he stopped drinking any carbonated sodas, which greatly reduced gut inflammation and almost eliminated the toe tingling and food sensitivities. He does not lay down for at least an hour after eating (helps the GERD.) He stopped eating wheat in any form which helped both the GERD and oddly, the leg cramps. If he accidentally eats wheat, his legs start to cramp up a hour or so later. He also used to get unwarranted anxiety attacks which have stopped after quitting wheat.

      You may not drink sodas or eat wheat, but you may be eating or NOT eating something (e.g. prebiotics and probiotics) that is causing your guy to be inflammed, which leads to a wide, confusing variety of health problems. Good luck!

    • says

      Hi Ricki H. I had those symptoms, it was like the operating system running my body was awry. Gerd, neuropathy, cold hands, declining immune system, and later, unexplained weight gain, lots of different diagnoses…. No answers.

      Turned out, I had a pituitary tumor. (Non-cancerous but still dangerous tumor that can scramble your whole body.). Maybe you should get screened for that. It involves an MRI without and with contrast dye. Doctors are not yet very well trained in diagnosing this. Average diagnosis time: TEN years, from onset of symptoms.

      ONE IN FIVE PEOPLE HAVE A PITUITARY TUMOR. For real. Check it out at Since surgery, my gut has been gradually healing. If that ends up being your situation, ping me at [email protected] and I can give you some tips on trwatment.

    • paleophil says

      Dr. Amy Nett wrote: “we do not obtain significant calories from RS.”

      Tater, maybe you can answer this–don’t we eventually get some calories from the RS after the bacteria ferment it and SCFAs are used, which are then used for energy by colon cells, mitochondria and brain cells, IIRC? I think you had some calculations on this?

      • says

        Wow, it’s getting hard to find these buried comments!

        Here is info on RS calories:

        When counting either total calories or carbohydrate calories, resistant starch is treated a bit differently. RS is not absorbed in the small intestine, therefore providing no direct caloric energy to fuel your body. Like other fiber, during fermentation in the colon, a little heat is produced. RS is, additionally, translated into a form of energy the body can use called short-chain fatty acids. These fatty acids are either absorbed into the bloodstream for use elsewhere (brain, liver, muscles) or used by cells that line the colon as energy to fuel their activities.

        Every 1 gram of RS is thought to provide approximately 1.5 calories (kcal) to the human body in terms of energy. Therefore, a daily intake of 40g RS would account for only 60 calories and should be counted as “fat” calories, not “carbs.” Like other omnivorous animals, humans are hindgut fermentors, and we derive about 10% of our total energy requirements from the alchemy of our co-habitants.

        – Behall, Kay M, and Juliette C Howe. “Resistant starch as energy.” Journal of the American College of Nutrition 15.3 (1996): 248-254.

        – Roberfroid, M. “The biochemistry of oligofructose, a nondigestible fiber: an …” 1993.

  68. Jen says

    Hello. I was doing a very clean Autoimmune/ketogenic diet (40/50g carb from veggies daily)for many years…and after a stressful job change my body cannot do it anymore…I guess. My thyroid and rnyitr digestive process slowed down and in have gained over 15 lbs in a year..(normally I am 108). Recent stool tests show low to no lactob. Butyr.And a high pH. All fibers seems to kill me too…..would RS help bring me back to balance??? In am so tired of feeling so heavy 24-7 esp all iny legs. My diet shifted to a more perfect health diet(80+ carb grams from veggies and sweet pot) which has helped moods but caused more weight gain.

    • paleophil says

      Jen, I don’t mean to scare you too badly, but I am concerned by your report. I’ve been seeing more and more reports similar to yours in which people were doing VLC and/or an AIP for years who developed immune dysfunction, thyroid disorders and many other problems. Isn’t an AIP only supposed to be done temporarily? I’m no physician, but if it were me and I didn’t start seeing improvements soon, I would get my gut microbiome checked and also an immune function test. An MD who used the handle “Spanish Caravan” wrote several Free the Animal blog comments on the topic and one of them was featured as an article (warning: the blog has crude language and insults, though the resistant starch articles and comments tend to have less of that). He reported that he developed Common variable immunodeficiency (CVID) on a chronic VLC diet. He also switched to PHD and then added RS and said he improved, though it didn’t sound like he was completely out of the water yet. Spanish Caravan predicted that we’ll be seeing more and more people like you reporting ill effects as the early adopters of VLC diets start getting hit with them and to some extent that seems to be coming to pass. I was a longtime VLCer myself who started developing subtly worsening chronic problems like low and erratic body temperatures and reduced insulin sensitivity. Even LC advocates like Mark Sisson warn to not go below 50g of carbs/day for more than temporary periods and even Dr. Ron Rosedale recommends a diet that contains 20% of calories as carbs! ( I’m glad to see you’re trying the PHD, though I think even that diet probably discourages legume consumption more than needed. Best wishes.

      • Jen says

        Hi paleophil. I am working on upping the carbs but have such GI issues even with Fodmaps. To be truthful the weight is my huge issue as it is constantly increasing despite eating clean,using bone broth, exercising…… My test results just came back from Genova and I am low on the good bacteria and have a high pH which shocked me…..I am wondering if I drop fats and add more 25+g would that help? I weigh and measure my food so I am super willing to try. Truth be told sleep is also something I need a bit more of…and I am taking theanine and seriphos to help…my functional ndr suggested.

        Thank you

      • says

        Jen – But there’s hope! I had the most messed up guts in the world in 2003. I was ‘force-fed’ ciprofloxacin by Uncle Sam for 5 months. Within a year I was fullblown met-syn with almost unheard of TSH level, fatty liver, and all the other fun stuff that goes with that. In 2010-11, I lost nearly 100lbs eating LC Paleo, then in 2013 started PHD due to some unwanted side-effects of LC as you’ve noticed. I have had 3 gut tests (for fun) in the last 18 months and there is no sign of pathogens, yeasts, or imbalances. I also have low lacto, but think that’s not a worry. My pH was at low end of Genova’s range and Butyrate was at high end. At that time I was on medium carb/high fiber diet, probably 100g carbs/50+g fiber.

        I think if you pay attention to lifestyle factors (sleep, exercise, stress, etc..), eat lots of fermented food, high RS food, and take a prebiotic supplement or two like potato starch, inulin, Larch AG, and/or psyllium, your gut will strive to maintain balance. Taking prebiotics helps set the stage.

        I think lack of lacto is OK because lacto often lives in small intestine and in biofilms and doesn’t show up in stool tests. Don’t sweat what you can’t control.

        The pH is a function of gut bugs and probably one of the best indicators of gut health. I wish there was an easy home-test.

        Gaining weight can be from many things: hormones, thyroid, inflammation, eating too much/moving too little (just kidding on last two). Keep on top of labs and get thyroid and hormones right, eat antiinflammatory/gut friendly diet and see what happens.

        Good luck.

        • Jen says

          Thanks Tim…

          I was thinking of starting on bobs red mill potato starch.. Slowly. What other high fiber veggies would you suggest? I eat summer squashes, carrots, green beans and lettuce often (34oz day). I do not do issues. Inipped my protein lately to from 8 to 12 oz daily and dropped from 10 tbsp fats a day to six. I have been prescribed cytomel for t3 issues but I rather not use at all anything synthetic… My dhea and testosterone was extremely low as well.


          • Tim Steele says

            Those are good veggies you eat. I don’t do much fruit, either. Greenish bananas are great…eat them as soon as you can peel them. At this stage they have 1/4 the carbs listed on the label.

            Nuts, esp almonds and psitachios are great fiber food. Dark chocolate, even better–cocoa nibs or cocoa beans–are exceptional fiber food. Berries of all sorts.

            Try 1tsp – 1TBS of potato starch a day, too. Mix in some yogurt or kefir if you do dairy, water if not. I sometimes just make a smoothie, gr. banana, blueberries, potato starch, inulin, etc…

            OK, now, I know this is highly inappropriate as I don’t know you or your history, but if you are eating 6TBS of fats per day as added oils, I think that is counterproductive. It sounds like you are trying to target an ideal macro ratio by using isolated oils.

            If you eat meat, nuts, avocado, fish, dairy, etc… (ie. real foods), you don’t need to boost the fat coloumn in your food diary with added oil. Just enjoy the natural fats and let the macro ratio work itself out.

            I do think it’s important to shoot for a protein of 50-75g depending on your size/workout levels. This can be easily accomplished by eating meat as you described.

            Just use enough oil/butter for cooking and salad dressing but don’t go out of your way to ensure a minimum daily intake.

            Some days I have 0 added fats, some days lots. I never intentionally add oil just for the sake of getting more fat.

            Find a good doc and get those thyroid/hormone levels right! Follow their directions, don’t play around with it. Get lots of labs and frequently.

            • Jen says


              I DO!! I feel so happy to get feedback. I have been praying for months for some guidance:)

              My one question is, is it good to add in RS if one had not done a herbal antibiotic route first to eliminate some of the buggers?

              My nutritionist said to just add in sweet potatoes and PS etc first.

              My fat is all in good areas if there such a thing….thighs and butt–thank you slow thyroid:). I am 19% body fat at 125 lbs and 101 lean mass at 5’3″. I normally am at 110 and have been forever, this past year my weight flew up.

              Thank you!

              • Tim says

                I think your nutritionist is giving good advice. Don’t get too wrapped up in trying to sort out everything at once. It’s really hard to give you perfect advice, so all I can say is just make changes slowly and let your body adapt, don’t do anything too extreme. Exercise, sleep, and be as stress free as you can.

                You’ll get there!

                • Jen says

                  Thanks again Tim..and everyone. I am meditating on all the advice….and know that the solution is there…just will take time. I am enjoying eating more variety and waiting on the weight loss for now.

          • Jen says

            Thanks Tim… You’re so helpful.

            Unfortunately I have a severe nut/seed allergy (carry an epipen) and dairy avocado etc done agree w me at all…hence my doing the autoimmune protocol to heal.

            I’m a 43 yo female… 5’3″ athletic build…but this extra 15+ lbs is slowing me down. In am running labs before I start taking hormones as I rather see if I can boost my metabolism and digestion. I don’t want to be depent on them for life. I exercise daily and mediate twice a day too. I am willing to try green banana or plantains as long as my bsugar does not go haywire. I get horrifically bloated w sweet pot and parsnips…but i do love them :) I added the fats BC I dont get much from my meats and its my only source of fats sometimes. Last year in was dropping lbs so fast I ate tons of fat to feel satisfied as my carbs were so low and my activity was so high. Now I feel I crashed nine months ago and have not had much progress to recover.

        • Allison says

          Tim – I’m intrigued by the comment about lacto living in biofilm and thus not showing up on stool tests. I have not been able to improve lacto levels on stool tests for 3 years now so this is very interesting. Other bacteria levels have improved but not lacto. Can you point me to any specific papers/resources to read more? thanks :)

    • Gemma says


      I can only share Paleophil’s concerns. Many people claim eating super clean paleo which by closer look is rather a very restrictive VLC diet. And many people have been mislead by believing that long term ketogenic or VLC diet is beneficial to health.

      It is not, especially not for women.

      Apart from protein and some fats, you need a lot of polysaccharides from different natural food sources to support your healthy gut flora, otherwise you are starving them. Hungry gut bugs are no fun. First, the beneficial species die out first or are are outnumbered by aggressive pathogens (bacteria, yeasts) that become very virulent and care for their own survival first. They can manipulate your immune system into a state beneficial to themselves mainly, and redirect the incoming calories into the fat tissue in order to keep their host alive. Meanwhile, they are eating you because they need to get their carbs from somewhere. I am sorry that this sounds so scary, but that’s how it is.

      It took you some time to get to this state and it will take some time to reverse it. Read the 7 steps protocol at Animal Pharm too, it is full of good instructions too.

      In addition to the advice already given by others, what about cleansing with medicinal clay, raw garlic or some herbals, to calm down or drive out the pathogenic species? Start slow.

      Do not be afraid to include some probiotic and eating various natural carb sources, to help establishing and maintaining the beneficial gut flora. Eat potatoes, beans (chickpeas is a wonderful food for a start) regularly, have some mushrooms often. Do not be afraid of carbs at all.

      Healthier microflora will help you in stabilising blood sugar too. Isn’t the aim to enjoy your food, not to weigh and calculate it before eating?

      Why are you afraid of fruits? What about a smallest organic apple you can find, including seeds, a day? Why not?

      Or what about a spoonful of honey before bed? Makes wonders for your sleep, and is healthy in many other ways, many probably not quite scientifically explored yet.

      I hope Dr. Nett or Chris Kresser can give some more advice, and it is good to know you are working with a doctor that can help monitoring all your issues.

      • Jen says


        Thank you. I stay away from fruit because it bloats me immediately. In started taking vsl#3 but found it triggered my bladder issues. I am guessing I have bacteria overgrown in that area. You are right as inate vcl and kept it up because in was super thin…which my ego loved. However this year I have suffered severe respiratory, bladder, and multiple ear infections with a side kicker of rosacea!! It has been horrible and I am guessing it is all from poor bacteria. Sugar is very triggering for me from fruits and honey etc. I am starting to eat more cooled sweet potatoes daily…. I have been taking oil of oregano and grafefruitseed extract and kombucha for seven months with no help. I am thinking I need to kill out the poor bacteria and then take the soil based ones afterwards. I am also eating more protein at each meal to balance bs better…I was not eating it at each meal and doing so now is helping. I am hoping the weight will start going down soon as it is hard to not fit in one item of clothing.. Especially my suits for work..: (.

        • Gemma says


          do take the tests so that you know better what you are fighting.

          I suspect bad bacteria and yeast overgrowth, in many places of your body. They work together – the partners in crime.

          Take the SBO now (start slow), what are you waiting for?

        • Duck Dodgers says

          Jen said: “I am willing to try green banana or plantains as long as my bsugar does not go haywire. I get horrifically bloated w sweet pot and parsnips…I stay away from fruit because it bloats me immediately.”


          “Bloat” is a normal side effect of re-introducing carbs. It’s just a temporary situation that goes away after a little time.

          For instance, take a look at the documented short term side effects of switching from VLC to the Perfect Health Diet (i.e. 150g of starchy carbs per day).

          Short-Term Effects of Adding Carbs to Very Low-Carb Diets

          Additionally, you’d probably do best to throw away the BG meter for two months, until your body can adapt to carbs again. It’s been well known since at least the 1920s that VLC diets will induce a kind of “false diabetes” that is cured over time with the re-introduction of carbs. For instance, Stefansson and Anderson were documented by Tolstoi to have given themselves this false diabetes after the conclusion of the Bellevue Experiment. Both men were “cured” after a few weeks with the reintroduction of carbs.

          See: The Effect Of An Exclusive Meat Diet Lasting One Year On The Carbohydrate Tolerance Of Two Normal Men, by Edward Tolstoi (J. Biol. Chem. 1929, 83:747-752)

          Magic? Not at all.

          VLC fucks with your brain and your body. Throw away the BG meter for a few weeks. Stop weighing yourself for a few weeks, and understand that these are short term effects that need not be over-scrutinized on a daily basis.

          In time, your body will adjust. Proper bacteria will begin to grow. Your gut pH will adjust. Pathogens that thrive at higher gut pHs will die, inactivate or get crowded out, and you will become normal over time.

          Good luck to you.

          • Jen says

            Thank you Duck.

            I don’t use a bs meter, I just go by feelings and focus.

            I am not afraid of carbs per say..but like fats better. I assume if I add carbs I will need to drop my fats. I started pot starch today as well as ox bile extract for my pancreas gallbladder issues and iberogast for motility issues. The good news is I am gaining some muscle…. And doing resistance training six days a week…but for 10-15 min…along with yoga and walking.

            Gemma. I will order the soil based organism soon….I have some inulin here too not sure how good that will be from chicory root.

            • Paleophil says

              Jen, Sorry to hear about the poor test results. I’m not big fan of focusing on weight loss more than microbiome health or general health (though morbid obesity is a clear health issue). Like Tim hinted at, I think fixing your microbiome, thyroid, and metabolism is probably more important, and then maybe weight loss will follow. If you’re eating a lot of fat and calories but having low energy, that suggests to me that your mitochondria are not getting fed well and your thyroid issue of course is a factor. It’s like you’re feeding the shell of your body, but not your gut bacteria and your mitochondria (which are descended from ancient bacteria). I’m not an expert and I don’t know you, though, and I could be wrong, so I would also check with your doc and monitor things with testing like Tim also said.

              I don’t know what the best carb intake is, but it increasingly looks like <50g/day is much too low for the long term.

              I found that trying to just up my carb intake very gradually didn't work well for me (though that has worked for others), whereas increasing my RS intake did the trick for me, gradually improving my insulin sensitivity and carb tolerance.

              I'm no longer shocked when I see poor gut microbiome test results from chronic VLCers. I wish I had known about the risk years ago.

              What is your oral or armpit temperature upon rising and mid-day and your resting pulse and do you have dream recall most mornings? These seem to be some pretty simple, albeit limited, home indicators of microbiome, thyroid and metabolic health. I found a glucometer to also be a helpful tool and they're not very expensive. I find that feelings can be misleading. I've seen way too many people say they "feel great" on VLC, only to experience problems down the road, including me. A glucometer can also help put your mind at ease. You might find that your BG doesn't spike as much as you thought. If it does, then it can help you find which foods you currently handle best, and try to improve your insulin sensitivity and carb tolerance over time. It was actually by measuring my BG that I found that potato starch was helping me dramatically within days, which was quite an incentive for me to stick with it, despite the early annoyance of mild flatulence.

              Were you told what the safe maximum time to do your autoimmune protocol is? If not, I'd ask about that and if you don't get a clear answer, I would be concerned. I think the goal of autoimmune protocols should be to quickly figure out what your problem foods are and then find a way to gradually improve your tolerance to the healthy ones, rather than stay on an AIP indefinitely. I think this is the standard approach of allergists, and I understand why now that I know more about the microbiome. I am seeing long-term AIPers reporting on the Internet that they are developing some serious problems, like thyroid problems, leptin resistance, thymus atrophy, GI problems, and more. Robb Wolf is an AIP proponent who said he improved from upping RS intake.

              It's also early in this period of people adding back RS to their diets, so also be on the lookout for problems from that. Who knows what we may still be getting wrong.

              • Jen says

                Hi paleophil

                In was not told a time frame for ai diet…I was doing it would knowing what it really was due to increasing good sensitivities.

                Do you count net carbs or total carb?
                Unfortunately my functional Dr is moving across country and is not leaving a replacement: ( so I feel a bit alone at the moment. I am dropping my fat intake in half and adding in about 10 oz more cooked starchier veggies w PS to see how I feel. Sleep and stress reduction are also key along with yoga and movement for me. Its a patience thing too….as I want to lose some of this weight but also start to enjoy food again and not worry so much about reactions from it….I am sensitive to even a pepper flake or salt shake now….

                • Paleophil says

                  Jen, this is also more concerning evidence suggesting immune dysfunction:

                  > I have suffered severe respiratory, bladder, and multiple ear infections with a side kicker of rosacea!!

                  Also watch out for triglycerides chronically below 50, which is turning out to be another bad sign that no one knew about until recently. It used to be thought that as low as 30 was safe. It may be a sign of a depressed immune system.

                  Another potential VLC side effect to watch out for is low white blood cell count.

                  I imagine your physician is probably already rather puzzled by your multiple immune-related problems. I would tell your next physician about these issues and that you went on a VLC diet and it may have messed with your immune system and you want to get your gut (and if possible, skin) microbiome checked and also get some immune tests done (such as IgG, IgM, and IgA antibody levels). See here:


                  Or do it yourself via Chris kresser or Dr. BG.

                  > [I] was not told a time frame for ai diet…

                  If they don’t have a time frame, then I would look elsewhere for information, such as here. AIPs are not long-term ways of eating. They were originally designed as short-term protocols.

                  > Do you count net carbs or total carb?

                  I don’t normally count carbs. I focus more on trying to eat a diverse, healthy diet that covers all the bases, and check symptoms, health metrics, and how well I function and feel (while not over-relying on the latter).

                  > I want to lose some of this weight but also start to enjoy food again and not worry so much about reactions from it….I am sensitive to even a pepper flake or salt shake now….

                  Isn’t reducing the worry about reactions to something as minute as a pepper flake and building up resiliency to them, such as with a more diverse microbiome, more important than weight loss right now?

              • Jen says


                that is so weird! the last time I had my trigycl. checked they were 19! and my total cholesterol was up 133 points!!
                I am looking to find another functional dr. as mine is moving across country. I just started this journey with functional drs. as regular MDs in ym experience are not helpful. I liked having afunctional dr as it is covered by insurance–as I already have spent over $8000 on naturpaths, acupuncturist, herbs etc etc.
                I am working on balancing the other pieces through diet and taking powdered inulin/chic root and PS. I am hoping to have some positive results soon. I am hoping you have some successes too!

                I am open to healing my bacteria issues through fruits and veggies but not grains..just personal choice,.
                A key piece is also sleep and stress and balancing a high profile job with motherhood of two little ones. I will say since my weight is up, my skin and energy have improved. I am taking 10 mg DHEA which is helping too as my DHEA was very very low as well as my sex hormones…

                • Paleophil says

                  Jen wrote: “that is so weird! the last time I had my trigycl. checked they were 19! and my total cholesterol was up 133 points!!”

                  That is also VERY concerning, Jen! Below 30 triglycerides is horrible and high and rising total cholesterol accompanying it can also be a bad sign (such as of the body trying to fight a bacterial infection). Please try to find all Spanish Caravan’s comments at the Free the Animal blog. Your numbers and microbiome results indicate a classic case of very depressed immune function and poor gut microbiome from eating too LC for too long. You are at risk for serious diseases like Common variable immunodeficiency (CVID) and virulent microbial infections.

                • Jen says


                  that is very disarming to hear….I wish I new at the time that VLC (25-40 net carbs a day) would be so dangerous!! I hope others do not have to go through the stuff I have….The whole point for most of us is to do Paleo to get healthy and in shape….this worked for a bit for me and then backfired. Lesson learned!

              • Amber says

                This is coming at such a good time! I have been VLC Paleo (but adding lots of raw milk) for almost a year, thought I was doing everything right, when suddenly got a rash by my eyes that wouldn’t go away. Doctors couldn’t help/no idea what it was. FINALLY, after my own research, I took diflucan and used a yeast cream on it, and what do you know? it was apparantly a yeast rash. So after all my hard work apparantly the systemic candida came back. Well, at least now I have a better idea why. I am a true believer in paleo, but I think I interpreted it wrong. Working now on making my diet 80% veggies/fruits rather than a 99% grass-fed protein and fat fest :) Thank you for talking about this (VLC Paleo) Info I definitely needed to hear.

            • Duck Dodgers says

              “I am not afraid of carbs per say..but like fats better”

              Unfortunately, you will need to curtail your fat intake from the high levels you were probably used to, if you want to avoid weight gain. Makes sense when you think about it.

              For instance, the Perfect Health Diet explains this in Chapter 43 for those who are trying to lose weight (adjusted for a 2000 calorie diet):

              “Carbs and protein are nutrients and they are not stored in the body, so eating less of them will lead to malnourishment. Fats are stored in the body— it’s all that stored fat that you’re trying to get rid of!— so you don’t need to eat much fat. If your diet is fat-deficient, any needed fats will be pulled from adipose tissue. As long as you continue eating some seafood for omega-3 fats and liver and egg yolks for fat-soluble vitamins and choline, you can reduce fat quite a bit with no risk of malnourishment. Therefore, the weight loss version of PHD is very similar to the regular version, only tweaked slightly to reduce fat:

              • Instead of using 2 to 4 tablespoons of fat or oil in cooking and sauces, use at most 1 tablespoon per day. Instead of a large dollop of butter or sour cream on a baked potato, flavor it with a small pat of butter plus vinegar and salt.

              • Replace fatty meats with somewhat leaner meats. When you have ribeye steak, instead of eating attached fat, trim excess fat.

              You’re still eating the same PHD foods, and they should still taste delicious. Quantities shouldn’t be much different than a normal diet, since you still need the same amount of carbs and protein. A diet with 500 calories from carbs, 300 calories from protein, and 500 calories from fats (primarily via egg yolks , liver, seafood, beef or lamb, and coconut milk) is the minimum caloric intake consistent with proper nourishment.”

              Source: Jaminet, Paul; Jaminet, Shou-Ching (2012-12-11). Perfect Health Diet: Regain Health and Lose Weight by Eating the Way You Were Meant to Eat (pp. 393-394). Scribner. Kindle Edition.

                • Jen says

                  Thanks Duck. It is a great article. I read it recently.

                  To your previous comment….I am unable to eat liver or eggs get severely bad headaches. The only fat besides what in add is from my meat…as ineat mostly poultry and fish..which isn’t that fatty to begin with. I have recently dropped my daily fat in half and added in a sweet potato, PS.. 1/2 tsp to start and am taking some digestive enzymes and kombucha. The good news is I am a bit less bloated but …..a bit hungrier and more constipated and dizzy for some reason.

                  Thank you kindly for your assistance.

            • Gemma says


              inulin supplement from chicory is fine, that is how it is produced mostly.

              And what about some fresh chicory, a lot of onions, leech, garlic, sunflower seeds etc?

              • Jen says


                those are good suggestions! I am allergic to nuts and when I eat seeds I get very weak for some reason. How would you prepare the leeks ? or onions? I usually never eat them. I am thinking of trying kimchee–slowly

                • Gemma says


                  you can eat the sunflower seeds just like this, peeled or unpeeled. Chew on the unpeeled ones and spit out the rest when it does not taste good any more.

                  The onions, leech, garlic etc: either raw in a salad, or boiled, baked, roasted, stuffed with something, whatever… :-)

                  Garlic: eat it raw, crushed with salt, let wait 15 minutes, then eat. Eat a clove daily, for a start. It is a very strong antibacterial, antiviral and antifungal plant.

                  Make ginger tea from time to time, too.

                  And perhaps, oil pulling with sesame oil. Easy to google how to. I think you might benefit a lot.

                  Good luck.

                • Tim says

                  Jen – do you feel what is happening here? Everyone has stopped trying to win the marathon and they are rallying around you to get you over the finish line! This is why I do what I do.

                  Everyone is giving you great advice, I hope you can make sense of it. When I was very broken, my trigs were over 2000. Taking two horse-sized Gemfibrozil pills a day got them down to 250. One month of VLC and no pills got my trigs down to under 30. I was so proud of my low trigs! But it didn’t last, I soon had a whole new set of problems.

                  Now that I eat 100-150g or so of carbs and lots of fiber, my trigs stay right at 120. Low, low trigs is probably a sign of improper diet.

                  Also, take Gemma’s advice and broaden your palate. Go out of your way to eat real, fibery foods. Eat a potato every day. Learn to use fresh herbs. Start putting raw garlic and turmeric on everything.

                  Sometimes people just get fat. For women ‘of a certain age’ losing a big booty is as hard as me growing 3″ taller. Just make sure your fat is under the skin and not around your liver and kidneys. (How was that, Lauren?).

                  Focus on health and develop a body designed by nature, don’t force it to look like you think you should look.


  69. Ashley says

    Hi all, I have a few questions. First off, in the article with sources of RS, raw oats is a good source and I wondered if then the recipes I find online for overnight oats would be good, where the oats are soaked in coconut milk and not cooked.

    Additionally, is there an RS amount difference in regular potatoes and sweet potatoes?

    And, besides potatoes, what other foods are high in RS? Green bananas and plantains, I get that, anything else I should add to my list? With respect to beans, how am I doing those. Is it best to get canned or dry and then soak overnight? Cooking? We really need a few good recipes. I definitely recommend overnight oats. I add chia and flax to mine and whatever to add flavor.

    • says

      I’m no expert on oats, grains, and seeds. I think what you propose sounds right.

      Sweet potato starch is fairly high in RS, but a sweet potato has very little starch. A white potato has 16-20% starch content a sweet potato has 10-12%. Sweet potato also has more sugar, as name implies. If you can find noodles made of sweet potato starch, sold as ‘Dangmyeon’ they are a very good source of RS3, nearly 40% I believe. I’ve never had them, keep meaning to look for them.

  70. Marion says

    Could someone elaborate on what is meant by “properly prepared cooked and cooled parboiled rice or legumes”. Does this mean Uncle Ben’s is the preferred rice? Do legumes also need to be cooled?
    Thank you

    • says

      To me, properly preparing beans means soaking 12-36 hours to allow fermentation by lactobacillus bacteria, then rinsing and cooking until tender, boiling at a rolling boil at least 10 minutes during the cooking.

      For rice, just cook however you like and store in frideg or freezer until ready to reheat and eat. Long-grain, colored (red, black, brown), or parboiled are the highest in RS. Short-grain and ‘sticky’ rices are lowest.

  71. Michele says

    Okay, just ate a raw potato. I always loved them as a kid (now 64). I had chronic heartburn and sinus infection and was having intestinal pain when before I quit grains and milk last January. If I eat too many carbs (sugars) the sinus problem starts to come back and if I eat bread the heartburn starts to appear. The gut pain went away immediately. So this is my test with the raw potatoes to see if anything bad happens and I will lay off completely any grains and sugary fruits. So far only one big burp!

  72. Amber says

    I’m confused… so cold potato salad or baked and cooled plantain chips would be RS…. What about properly fermented (WAPF style) bread? Rye or Spelt, or even wheat? Or what about Oatmeal soaked overnight with whey?

    • says

      No idea. Just not enough studies on it. I think WAPF style foods are all good for their own reasons, RS or not. Fermenting grains changes them in good ways, what that does to RS I have no idea.

  73. Melina says

    Hi Chris. I’ve been following the topic of resistant starch for a while now and experimenting with it. I have read all your posts about it and other people’s as well. I have Hashimoto’s and I’m currently doing the autoinmune protocol. Most of my symptoms are gone except constipation. I can not do potatoes during the AIP. So I read that casava also have a hig amount of RS and added to my diet in the form of tapioca starch. To my surprise it relieved my constipation almost right away with only 1 Tsp. Then in one of your potcasts you said that casava has very high amounts of goitogens and coking will decrease them. But cooking will damage the resistante starch. So I’m a little lost here. Can you please coment on this? Thanks a lot.

      • h says

        Excluding the Pringles, was your diet and lifestyle, exercise, exposure to toxins etc exactly the same as it is now? That there were no confounding Factors? The only difference was the Pringles?

  74. says

    When taking in RS in the form of potato starch is there an optimal time to ingest it? Beginning of the day, end of the day, with meals, empty stomach, with probiotic foods/supplements, etc? Is just once a day suffice? Thanks!

  75. Teri says

    Any thoughts on RS for those of us on an auto-immune protocol, with no nightshades?

    I enjoy green plantains, but sure do cook them! If they’re cooked, say into crackers, but then eaten at room temperture, does that bring back the resistant starch?

    • says

      Cooking changes the RS structure. In any food that contains RS, there will always be more in its raw state than cooked and cooled…lots more. A big plantain can have 30-50g of RS raw, when cooked and cooled it drops down to 5g or so.

  76. Jen says

    Thank you for the article. I have been adding potato starch to my diet for several months. My doctor recently recommended that I try taking digestive enzyme supplements to help with gas/bloating that I have experienced for several years. Would such supplements weaken/negate the benefits of added RS in my diet?

    • says

      Probably none. Lots of people have been using different enzymes along with prebiotics.

      Most of the Bean-o type stuff is just masking a poor gut flora that can be corrected with eating RS rich foods, though.

  77. darren says

    Why the bias against “Hi-Maize”? Is it just because it’s made from corn (and therefore not “paleo” – which I could give a crap about frankly)? Or because it’s processed and possibly has weird stuff in it (more important to me). One advantage of hi-maize seems to be, unless I’m mistaken, that it actually maintains its resistant starch when cooked unlike potato starch which seems like a huge benefit. I’ve only tried cooking it once (in pancakes – resulting taste = awesome), but mostly take it raw and I’ve tried both hi maize and potato starch and as long as I take it with a probiotic I don’t have any headaches or issues with either(got those when I first started PS). Both seem to have fixed the gut problems I used to have. Seems like either is fine to me.

    • says

      Hi-Maize is fine. I don’t like recommending it much because there is only one source and it is a bit of a frankenfood with some mystery as to its exact origins.

      The makers, Ingredion, are the fine people who brought us High Fructose Corn Syrup. The onus is on them to convince us they have our best interest at heart and not just finding new markets for US corn. Their ‘gig’ is using Hi-Maize as a food additive to allow a ‘High in Fiber’ label to be affixed.

      So, yes, I’m a bit jaded. At least with potato starch there are several manufacturers and brands and I can make it at home if I want. I have no idea how to make Hi-Maize or how many ears of corn it takes to make 4TBS of Hi-Maize. I don’t really even know if it’s RS2 or RS3. Also there are several different ‘styles’ of Hi-Maize. There’s Hi-Maize 220, 230, 240 and more…have a look:

      Oh, it takes one big potato to make 4TBS of potato starch.

      • says

        Just a side note: Here are some other fine products from the makers of Hi-Maize, mmmm mmmm good!:

        The following are registered trademarks of National Starch and Chemical Company:


        • darren says


          Thanks for the reply.

          Point taken. At any rate, I have a big giant bag of the stuff so I’ll probably just finish and stick w/ potato starch and green bananas from then on. :)

          • Ellen says

            I would assume the High-Maize is made from GMO corn, which probably contributes to the high rates of dysbiosis as well as poisoning non target species in the environment such as the monarch butterfly.

  78. David says

    Is Bob Mills RS cooked in the powder form? It does say 10g of carbs on the nutrition segment on the bag.

    Yes you can. In it’s raw state, it’s nearly 100% fiber. The nutrition label is for cooked potato starch.

  79. Rob says

    My son has a bad case of Ulcerative Colitis. Do you know if RS might be good for him? I had heard that prebiotics might not work well with him.
    Thank you for the great article and the great interaction! ~Rob

  80. Andy says

    @Tim Steele
    Tim, you mentioned on your website that “Potato salads loaded down with mayonnaise or oil might keep your intestines healthy, but all that fat can pack on the pounds.”
    I think the wrong fats pack on the pounds, but a home-made mayo with healthy fats or full fat cream won’t.
    Is there anything wrong with consuming potato with fat? I understand that fat with potato reduces the GI factor of the potato. Can you clarify this, please. Thanks

    • says

      I’m not ‘low fat’ by any means. It was just an observation on all of the news articles of the last 10-20 years that concluded potato starch was the best source of RS.

      Potato salad is A source, but not the BEST source. Potatoes are probably best consumed with fat, as you say. Just don’t eat a quart of Kroger’s Best potato salad and think you will be super RS man.

  81. Rob says

    My son has pretty bad Ulcerative Colitis. I had thought prebiotics were not good for him but after reading this I can see I was possibly wrong. What forms of RS might be helpful to him?


  82. Andy says

    I have a protein shake in the morning after my workout which will be an ideal time to add the starch. The shake contains amino acids, magnesium, lecithin and gelatin. Are there any issues in taking starch with protein and/or supplements – is this combo acceptable or should it be consumed separately? Thanks!

    • says

      I really don’t have an issue with Hi-Maize if used in it’s raw form. I’m not a fan of gluten free baking in general, but if that’s your thing, Hi-Maize is fine. Banana flour better, I believe.

      Synthetic RS is not available to the consumer as far as I know, just food manufacturers. Google ‘Penfibe RS’ ‘BarleyMax’ or ‘CrystalLean’. I’ve never seen anyone selling small quantities and I wouldn’t recommend them if I did. Frankenfood as far as I’m concerned, but who knows, maybe somebody will market a good one for consumer use. I’ll stick with potato starch.

  83. Starch says

    What happens if resistant starch potato flour is heated above 130 degrees, and then cooled? Will it be resistant starch again, or is it changed to something else? For example if it is used in baking, crisp bread etc.

    • says

      It transforms from RS2 to RDS (readily digestible starch) when heated, then begins to form retrograded RS3 when cooled to below 50 degrees.

      The percentage of RS in potato starch will go from approx 65% when raw, 0% when cooked, and maybe 2-5% when cooled. Repeated heating and cooling cycles will increase the RS3 slightly to maybe 6-8% with 3 or 4 cycles.

  84. says

    I have been reading everything about RS I can get my eyes on… And I have three questions.
    1. How important is it to ingest organic potatoes? I’ve read they are super high in pesticides when conventionally grown. I’ve also read that more RS and butyrate helps block (to describe it completely unscientifically) negative pesticide effects.
    2. I saw an organic PS on amazon but it was stated that it is not raw—because to get the starch out, they heat the potato. I am assuming it has been verified Bob’s PS is raw?
    3. I asked my husband to grab a plantain at the store… He did, and it was not green (it also tasted kinda sweet). Does a plantain need to be green skinned to have the RS (at the 50% by weight amount)?
    I am not a patient person and I am itching to add more RS to my diet (without increasing my carb intake because I like to be really lean and I wanna lose my 10lb baby weight)… I just want to do it right so it’s effective! Thanks in advance for insights.

    • says

      1. How important is it to ingest organic potatoes? I’ve read they are super high in pesticides when conventionally grown. I’ve also read that more RS and butyrate helps block (to describe it completely unscientifically) negative pesticide effects.

      — If you are eating raw potatoes, please buy organic or home grown if possible. Yes, potatoes from Safeway are generally covered in stuff deemed ‘safe’ by the USDA but not so great in reality (herbicide, fungicide, sprout inhibitors). RS will hopefully help create a better gut flora. A well-functioning gut flora can chelate toxins and pesticides for you. A fiber-filled diet results in decreased transit time of your fecal matter, meaning less time for toxins to absorb. This doesn’t make it OK to eat bad food on purpose, though. If you need to eat cheap taters, wash and peel them before cooking.

      2. I saw an organic PS on amazon but it was stated that it is not raw—because to get the starch out, they heat the potato. I am assuming it has been verified Bob’s PS is raw?

      — Probably the company selling the starch doesn’t really understand the process. Starch production starts by blasting the potatoes with hot water to remove peels and dirt, from that point on its all done cold. Potatoes are finely ground and the starch is filtered through increasingly smaller sieves. Finally it is sprayed onto rotating drums or screens and air dried. Any deviation from this will turn the starch production line into a gooey mess. There is a market for pre-gelatinized (cooked) potato starch, but this will be labeled as ‘modified’ or ‘pre-gelatinized’. This type of starch will thicken with room temperature water. Easy to test. Just mix with water and see if it settles to the bottom of the glass or gels up. My guess is that anything sold as ‘unmodified starch’ in the US is just that–raw starch granules that qualify as RS.

      3. I asked my husband to grab a plantain at the store… He did, and it was not green (it also tasted kinda sweet). Does a plantain need to be green skinned to have the RS (at the 50% by weight amount)?

      — Even green, unripe plantains might have some black spots on them, but they need to be very green and very firm. They rarely turn yellow even when very ripe, but they get soft and blacker skin. You will need to peel an unripe plantain with a knife for sure. When you cut up a really green plantain, you will find a white, starchy residue on your knife and fingers when you are done. Plantains are more forgiving than bananas as even when really ripe don’t have very high sugar content. But get the greenest, firmest ones you can find. You’ll get the hang of it.

      If you are really bored, click on my name and look around, I collected about 100 RS articles from the past year and put them in one place. Use the search function if you get tired of reading, but lots of info there.

      • Duck Dodgers says

        How important is it to ingest organic potatoes? I’ve read they are super high in pesticides when conventionally grown.

        Interestingly, organic potatoes are believed to have more glycoalkaloids than conventionally grown potatoes.

        Perhaps when man-made pesticides are absent, the potato compensates with higher glycoalkaloid output.

        Of course, there appear to be beneficial hormetic effects of some glycoalkaloids…

        From: Potato Glycoalkaloids and Metabolites: Roles in the Plant and in the Diet

        “Food and biomedical scientists, including nutritionists, pharmacologists, and micro- biologists, are challenged to further define the beneficial effects of the glycoalkaloids against cancer, the immune system, cholesterol, and inflammation, as well as against pathogenic fungi, bacteria, viruses, and protozoa.”

        So, as long as you can tolerate them, glycoalkaloids may be good for you. Natural pesticides for the win!

  85. Evan says

    The table in the linked article on RS research shows
    uncooked rolled oats with nearly triple the RS of bananas,
    and certain breads and cereals higher than any of the potato amounts, with pumpernickel being the highest . Eating” uncooked rolled oats” – which I believe have been steamed and then industrially flattened – or yeasted wholegrain breads would seem to
    then not meet the criteria for proper preparation for digestibility/phytate neutralization. Isn’t that a concern?

    • says

      There are still lots of unknowns. Oats have the potential to be a ‘superfood’ of sorts due to their beta glucans and RS. It’s the processing methods that destroy these properties. I think old-timey raw, rolled oats, soaked overnight, are really good for your guts. Instant oatmeal, no.

      Same goes for cereal grains, but I don’t like wheat. The WAPF has the lowdown on cereal grains. Maybe Laura Schoenfeld has more ideas on making grains healthy.

  86. Ann says

    I have been battling with dysbiosis in the gut for over 5 years.. My colon is sick and very leaky as well as other parts of my intestines and colon. The latest stool test showed elevated cholesterol and also no lactobacillus in the stool. I eat yogurt so why no LB? I have a fungal infection longstanding for 5 years also plus blastocystis hominis, I am pretty weak and my liver is being affected now as the fungus is eating my nutrition. Please help.

  87. Amb says

    Would eating green plantain crackers be considered an RS source? They are cooked but then eaten after cooling. Are sweet potatoes a source or just white potatoes? I am following AIP and sensitive to nightshades so I am not wanting to challenge the potato starch just yet and have not yet challenged rice or beans, etc. (cooled or otherwise). Green bananas don’t seem to bother me but I know I should mix up the sources and the foods AIP offers to sneak in some RS flour are limited.

    • Amy Nett says

      Hi Amb,

      Based on the reference I used in this article, sweet potatoes and yams are a source of RS. Though I don’t think you will be missing any benefits by choosing to get your RS through plantains (or plantain flour) and green bananas.

      And I would think that the plantain crackers would be a source of RS, as would dehydrated plantain chips.

  88. Sonia says

    Sorry if this has already been addressed, but could I just put the potato starch in a little water and drink it that way?

    • John Es says

      I take mine by mixing powdered psyllium husk and raw potato starch, dry, and mixing with water in a shaker bottle. The mixture of the dry components keeps the psyllium from clumping as easily, and the starch won’t settle out as quickly.

  89. nancy says

    I did not see an answer to the type 2 diabetes question and I have the same question. If I eat beans or rice my sugar rises significantly and stays up for a day or two(code word :stabilizes blood glucose) I’m also nightshade intolerant. How many dehydrated plantain chips would it take to achieve 15g RS?

    • says

      Fully green plantains, dried, are roughly 50% by weight RS. If I remember right, a large plantain, dried weighs about 100g so 50g of RS per plantain when dried.

      When I make them, I slice them lengthwise into about 4 slabs, I know each slab will contain about 12g of RS. They make great cracker when done this way, great for almond butter, pate, etc…

      Your concerns about BG with cooked/cooled RS is a valid one, for prebiotics also consider Arabinogalactan, Beta-glucan, Inulin, Oligofructose, and that sort of thing. RS only one way to skin the cat, not the be-all end-all to gut health.

      • says

        I have no idea if you’re reading these comments almost a year later. You write above “Arabinogalactan, Beta-glucan, Inulin, Oligofructose, and that sort of thing.” One of my nutrition teachers insists that to feed the microbiome properly, one must include ALL of the following, without exception: psyllium, acacia, FOS, inulin, PS, plantain flour, spirulina and chlorella PLUS SBOs and a high concentration of aerobic probiotics, like 500 billion. Eventually the probiotics are reduced but not the fibers and prebiotics. I’d like to reduce the number of prebiotics and fibers, especially the algaes, because I’d like to incorporate good protocols with my patients, and where I live it is very difficult to get people to do all of the above (expensive, overwhelming, yucky tasting…). What do you think is a well rounded protocol of fibers and prebiotics in entirety? I’m not so concerned with probiotics, more the bacteria food – to be well covered. Besides the food additions that is, I’m talking about supplemental. Thanks!

        • says

          Laura – Please look at

          Here we see evidence that more diverse prebiotics leads to less bacterial diversity.

          I have good reason to believe this is also true for humans and I have shifted to thinking that it may be best to use just one type of fiber, such as inulin or RS as tolerated than mixing a blend of all the fibers you can find.

          Also, just out: Resistant starches differentially stimulate toll-like receptors and attenuate proinflammatory cytokines in dendritic cells by modulation of intestinal epithelial cells. found at:

          It appears RS may have more tricks up its sleeve than simple gut bacteria food!

          This was also explained by Dr. Art Ayers at his blog, Cooling Inflammation, a while back:

          ” Each healthy human maintains a subset of a couple of hundred of the couple of thousand different species of bacteria found in humans around the globe. The diverse community in each individual may differ in species, but has approximately the same complement of genes in people sharing the same diet.

          1-200 different species of bacteria per person
          1-2000 different species of human gut bacteria
          1 million different genes among the different bacteria
          Most genes are involved in digesting plant carbohydrates, i.e. soluble fiber: inulin, pectin, fructans, algal sulfated polysaccharides, etc.
          Diet diversity, e.g. the Modern American Diet, reduces the diversity of the gut bacterial community, presumably because the rapid change in foods permits survival of only generalist bacteria that can digest many different foods.
          Simple diets produce gut flora diversity, but only if there is access to diverse bacteria.
          Health may result from diverse gut flora developed from a simplified diet and ample bacterial resources.
          Obesity and other diseases may result from simplified gut flora developed from a changing, complex diet and a sterile environment/isolation.
          Vegan and paleo extremes can lead to healthy gut flora diversity, if the gut bacterial community is permitted to adjust to the diet composition by avoiding rapid changes and providing diverse bacterial sources.
          Meat contains complex polysaccharides, e.g. glycosaminoglycans, such as chondroitin sulfate and heparan sulfate proteoglycans, which are bacterial fodder equivalent to soluble fiber.
          Probiotics are unique bacterial species that do not persist in the gut of adults, but dominate the gut of milk eating babies and stimulate development of the gut and immune system.
          Probiotic bacteria can temporarily provide developmental signals for immune system development that are normally provided by a healthy gut flora.
          Antibiotics cripple gut flora needed for development of the immune system.
          Common medicines have significant antibiotic activity and modify gut flora.

    • Chris Kresser says

      People with GERD often have SIBO, and RS is *potentially* (but not always) problematic with SIBO. I would exercise caution for sure.

  90. Valerie says

    Are all potato starches equal and are all potato starches unmodified? Just bought some but the store didn’t have Bob’s Red Mill, so I bought what they had out of the bulk bin. Only wondered about this afterwards. I’m basically paleo, except I do have unhomogenized guernsey milk with coffee. I plan on experimenting with RS. Will have some mashed potatoes one day and see what that does to my BG, then another day, cool the mashed potato and then add RS and see if it makes a difference in BG. I think Tatertot has done this with success at lowering the glucose effect of the potato.

    I got very interested in this from Tatertot. Thank you Amy for this article so timely for me.

    • says

      The only thing you need to be concerned with when buying potato starch in a food aisle of a food store is whether or not it is actually potato FLOUR. To test, mix a spoonful in a glass of water, if it all settles to the bottom in a hard, cement-like paste–it’s starch. If it clumps and globs like biscuit dough, it’s flour. If you really want to be sure, buy some known potato flour and some known potato starch and compare the two. Then you’ll have a baseline. In the US, starch is always starch and flour is always flour, in other countries the terms are used interchangeably.

      The deal with modified, you won’t see it in a food store except maybe the laundry aisle–it will say ‘modified’ don’t use it, not food grade!

      • Valerie says

        Thank you so much, Tim. I did as you suggested and yes it’s starch. Never buy in the bulk bin, except this time. Thank you also for all the help you gave me and others, on your comments here and on freetheanimals. I’ve learned so much from you. I’m definiately a fan.

  91. Wenchypoo says

    Bagged potato starch is a PROCESSED FOOD–to make it UNprocessed, boil potatoes, then allow to cool for at least 24 hours before eating. Eat cold for maximum resistance effect.

    I do potato salad in this manner, because Hubby’s BG cannot tolerate the processed stuff. We feed our gut bacteria with probiotics and Bubbie’s pickles.

    This is Hubby’s weekly Carb Nite solution for controlling FBG.

    • says

      Hi, Wenchypoo!

      You are right, but people like easy. I do, too. You know, I often make my own potato starch. It is so simple and you can get so much out of 1 potato you wouldn’t believe.

      I wish there were a minimally processed potato starch on the market with nothing added, non-GMO certified and organic. It would be grayish is color, but who cares?

      The only real additive of concern in potato starch is sulfur, but there is much, much less than a glass of wine or a dried apricot. they add it to keep it bright white. Other than that, nothing else is added. they just clean, grind, and separate the starch. Much less processing than say, whey protein powder or inulin supplements.

      Your concern is noted and welcome, potato starch is not everyone’s cup of tea and I’m glad there are alternatives.

    • Paleophil says

      Cooking is also a form of processing. While I think the goal of eating the whole food is a good one, cooking is not without risk. Cooking produces some toxic byproducts like advanced glycation endproducts (AGEs) associated with aging that there is lots of research showing negative effects from at high doses (though low doses theoretically might be hormetically beneficial).

      The level of aging-related toxins like AGEs in the skin has started to be used as a marker for biological age in Europe. I know a mature raw omnivore who reported that she was found to have so few of these toxins in her skin that she was measured as having the biological age of a young child! While that’s not solid evidence, it is an interesting anecdote that gives me pause and fits with my own experience. I think we’ll see more about this in the coming years.

      • Duck Dodgers says

        Good stuff, Paloephil. I completely agree, and prefer to lightly cook foods. But, it’s worth pointing out that at least when it comes to plants, cooking can reduce non-AGE toxins down to hormetic levels. We don’t want people eating raw or undercooked kidney beans :)

        • Paleophil says

          Yeah, kidney beans would be a food I would cook (low and slow). There are also other traditional forms of food processing beyond cooking, such soaking, fermenting, sprouting, drying, freeze-drying, freezing, smoking, and others.

  92. Heather Burkhardt says

    I am interested in the proper prepartion of legumes, black beans in particular. What is their RS content? I am also curious about raw peas too, both English and sugar snap. I am way more inclined to put some cold beans on a salad, than buy packages of powders.

    I also wondered about folks who get histamine reactions, can anyone speak to that?

      • Heather Burkhardt says

        Thanks for your reply Tim, I checked out the link. I think my soaked overnight, pressure cooked black beans are ok. :)

      • Heather Burkhardt says

        Hi Chris, thanks for the inquiry. I certainly get a histamine reaction from grass pollen and found that if I stayed away from high histamine foods during that time, I could somewhat manage my allergy symptoms, up until the wind really blows or the farmers are making hay and stirring everything up. After the pollen abates, I seem to be able to manage high histamine foods without overt symptoms, but I know I have a sensitivty to them. Years ago (before dietary changes) I had a full on histamine reaction to red wine and reggiano parmesan. So, just curious if RS would feed histamine producing gut flora and would a histamine sensitive person want that?

        • Chris Kresser says

          I haven’t seen any research on this question specifically. However, my experience clinically is that restoring a healthy gut microbiome with both prebiotics (including RS) and probiotics typically leads to improvements in histamine tolerance.

    • says

      Not yet, but I’ll bet in a few years there will be all kinds of RS magic potions at GNC. For now, potato starch is cheapest and easiest. I will lay a wager that most commercial RS blends will contain potato starch.

    • Sam says

      Your best bet is probably just to find some kind of food you enjoy and add potato starch to it. In my case, I love milkshakes with frozen raw milk and a touch of coffee and cocoa and stevia for sweetening. I add yucca starch to that, as potato starch isn’t available where I live. It’s truly delicious, which makes it a pleasure to get my RS.

  93. sherman says

    Dunno about potato starch, used to bake GF with it. Instead, found a ground larch fiber from Dr Marshall, who said it is the highest butyerate developing fiber he has ever seen. Works well when I remember to include it, but please heed the warning to start really slow, and gradually increase usage, especially if you have any gut or autoimmune condition. Here’s the thing: sugar and refined carbs feed pathogenic gut bacteria, so you need a clean diet first, or it is mostly a waste of time.

    • says

      Larch is great! Contains arabinogalactin, a very selective prebiotic. It’s downside is cost. When you buy an expensive jar of Larch AG pills, the dose is like 1g. I believe you’d want 10-20g for good effect. Similar to inulin, manufacturers keep the recommended dose so low it doesn’t make consumers fart, God forbid!

      Glucomannan is another great prebiotic similar to Larch AG.

  94. says

    Is it ok to use prebiotics/RS when there is a intestinal yeast overgrowth? I was told that prebiotics could feed the yeast so it is best to stay away. Thanks!

    • Amy Nett says

      Hi Rebecca,

      As with other types of gut dysbiosis, as you work towards rebalancing your microbiome, it is probably best to avoid RS and other prebiotics for a time while you treat the yeast.

  95. Michelle says

    Tim or anyone – I have been taking about 2 TBSP PS for a month or so now with good effect. However, if I consume Dandy coffee substitute (chicory, dandelion, etc. in it) the gas factor seems multiplicative. Does this suggest dysbiosis? Or just a bad food combo?? It feels like RS and inulin having a pillow fight in my gut. Not as sexy as it sounds. :)

    • says

      Inulin is degraded by a completely different set of gut bugs, so it makes perfect sense what you describe. In nature, RS and inulin are never found together in the same plant for the most part, and really not even in the same geographical locations.

      If anyone wants to use inulin as their main prebiotic, they’ll find it’s even harder to get from normal food sources and needs to be supplemented at about the same dose as potato starch for good effect. Again, our paleo ancestors had no problem getting inulin in their foods, American paleo-Indians said to eat over 100g of inulin-like fiber/day.

      I have a jar of inulin powder and I add it to a smoothie once or twice a week just to mix things up. It always makes me more ‘vocal’ when I do it, too.

      • Michelle says

        Thanks Tim! I will try not to consume them so close together… I cannot imagine what 100g of inulin would do. Warm up a teepee or cave at night, I suppose. :)

  96. says

    I’ve tried RS in form of potato starch (not Bob’s red mill, I”m in Europe so it is inconvenient to order it from other contries atm). I got serious hives all over my body and it took me a few months untill they went away. I wonder since I didn’t have problems with my gut does this still might be a sign of SIBO? I’ve also written to Richard Nikolay about this, and he advised me to try hi-maize when I’m healed, but I’m hesitant to do that…

    • Amy Nett says

      Hi Agne,

      I think you are absolutely right, and hives or other skin manifestation as a response to RS, could be due to SIBO or other gut dysbiosis. Gut bacterial imbalances may manifest with symptoms other than the more classic GI symptoms, such as skin rashes, hives, brain fog, or mood changes including dysthymia (depressed mood).

  97. Mark says

    Twice I’ve tried supplementing with RS steadily building up to the prescribed dosage and on both occasions it felt like my immune system fell apart. I am a healthy person (as far as I know) eating ancestrally for about 4yrs who would normally get a cold 1-2 times every 2 years but each time I’ve tried RS I have ended up getting colds every 2-3 weeks after RS for about 3 months. Anyone with any thoughts on what might be going on here would be much appreciated.

  98. Mitch says

    Hallo Tim,

    Does RS starch also feed bad bacteria? In other words if I expect a overgrowth of pathogens does the RS feed them more than the good bacteria?



    • says

      Yes, certainly it does feed pathogens. However, in a healthy gut environment, RS will mainly feed a few high-profile RS degraders that produce butyrate and also other end products that result in increased probiotic strains (eg. lacto, bifido). The entire gut ecosystem benefits by the lactic acid produces (create stable pH) and increased butyrate (feeds colonocytes and boosts immune system). Whatyou are after is a gut that takes care of itself and crowds out the pathogens and makes life miserable for them.

      If you are starting with a gutful of bad guys, all bets are off.

      Read all of Chris’ posts on RS and listen to his podcasts…he is taking this in the perfect direction. Use RS as a litmus for your gut health. Start slow and work your way up. Use probiotics to increase success of creating a healthy gut.

  99. Jennie says

    I activate brown rice, then dehydrate and store in the freezer for cooking later. Will cooking, cooling and reheating (to 130 degrees C) the activated brown rice still provide resistant starch?

    • paula says

      I have experienced more vivid and anxious dreams when using Bob’s Red Mill potato starch in my morning shake.
      Mark Sisson (Mark’s Daily Apple) has also mentioned this as have a few other bloggers/websites.
      Might be something more going on with gut bacteria when fed RS? Once again – clearly person dependent!

    • Boundless says

      > … anyone experienced symptoms of anxiety and rage while taking RS?

      Your remark is the first I’ve seen on that since starting to follow this story early this year. Tim surely has more exposure to the possibly wide range of idiosyncratic reactions.

      > Then I came across these

      I’d like to see the full reports. The first is apparently pay-walled and the fulltext pdf of the second is 404. The abstract for the 2nd looks to have confounding factors, possibly fatal. All 3 diets were pretty high glycemic. The RS was cooked and cooled rice which is not very high in RS, contains wheat germ agglutinin and is often contaminated with high levels of arsenic these days.

      • Matt says

        Here you go

        I’ll try to dig up the other.

        Here’s the conclusion:

        In conclusion, increased fermentation with increased
        concentrations of lactic acid and VFAs in the hindgut of
        rats is associated with increased anxious and aggressive behaviour. The current rat model of acidosis appears to be a valid and reliable model to use for human research and has direct clinical implications. Researchers need to consider diet as an important methodological consideration, which can interact with a number of variables under investigation. The study of the mechanism of action leading to nutritional effects on anxiety and aggression warrants further empirical
        and clinical research.

        • says

          Matt, my man! We got a lot to talk about!

          Two studies, one year apart, from the same guy on basically the same experiment. Done in Australia only a few years after the discovery of RS.

          A bit of background first: Australia has the world’s highest rate of colon cancer (CRC). Despite nearly 30 years of advice to “Eat Moar Fiber” their CRC rate went up. The Australian Health authorities (CSIRO) deemed that everyone should instead start eating more Resistant Starch. Not everyone liked this, namely because long-term studies had not been accomplished, and secondly because it was a government intervention from a government that is maybe not in the best position to tell people how they must eat.

          CSIRO’s effort to get people to eat ‘MOAR RS” involved teaming up with some Big-Ag types (Ingredion/Penford) who then developed some nifty new products, ie. BarleyMax and Hi-Maize. These high RS starches are to be added to cakes, cookies, bread, pasta, etc… so that the population will get their MOAR RS without having to actually think about it. CSIRO and these big-AG people spent millions/billions on advertising, making flashy fliers, and videos to show people how wonderful RS is. People don’t like that. I’d hate it. And, it kind of backfired on them as people rebelled against this new government plan.

          OK, to the studies:

          They are poorly designed, first off. They used cooked and cooled rice for the RS diet (FC diet) and wheat for the ‘stomach digested’ diet (SC diet).

          The SCFA amounts don’t follow their presumptions: Look at Table 3. Now that you know what SC and FC mean, try to form an assumption of SCFA concentrations that are amazingly different from each other or are way higher than the control. Butyrate at 21hrs, for example….highest in control diet. Total VFA (SCFA)…highest in wheat diet at 3 and 21 hours.

          pH not different among any diet. Nothing indicates the FC (high RS) diet is doing terrible things.

          Look at Table 4, the only thing that jumps at me is a dopamine level 400% higher on the SC (wheat) diet at 21 hours. This study should be used by Dr. Davis in his new Wheat Belly book.

          The rest of the tables looking at aggressive behaviors don’t really strike me as significant and in the conclusion the researchers all but admit their are too many confounding factors to make a good conclusion.

          The fact that this line of argument has disappeared and no more studies have come up with similar conclusions tells me that this was a dead-end, and just an attempt for these researchers to spark some new lines of study and thinking before making their entire country a nation of aggressive lab rats.

          Here is a much better study, in my opinion. It measures SCFA directly in ileostomy patients after being fed several different prebiotic fibers, including RS. Note Figure 1: It shows the amounts and percentages of SCFAs formed after fermentation in the large intestine. Each fiber type has its own unique signature. RS is not that much more amazing than inulin, but it does produce more butyrate than all the rest, which is somewhat amazing.

          Here is full text, I think this is a 90 day free trial, so download the pdf if you want to see it again!

          Now, to address the elephant in the room.

          I stopped trying to figure out what happens to people who add RS to their diet a long time ago. I will never say ‘you are making this up’ or ‘it’s all in your head’. Does anyone remember ‘Nancy’? Suffered terrible diarrhea after eating small amount of RS. She had her gut microbiome tested…25% of her entire gut flora was composed of Morganella Morganii, a major pathogen implicated in all sorts of illnesses.

          I still stand by my statement: If RS gives you problems, it’s not the RS–it’s you! Get your gut biome tested, do some interventions, don’t just accept poor health. If you are happy with your health and don’t do well on RS, don’t do it. That simple. We are all different. RS is not magic, just a fermentable fiber that certain beneficial gutbugs love to eat.

          Sorry for the inappropriately long comment!

            • says

              Two ways of looking at this…if you just want to look ‘for fun’ without getting a doctor involved, there are American Gut ($99–takes 6 mo) and uBiome ($89–takes 2-3 mo).

              If you want an expert opinion, you’ll have to see a doctor. Many use a test called Metametrix GIFX or similar. This can cost considerably more but insurance often covers. Practitioners of functional and integrative medicine are more in tune with these tests than conventional medicine/family practice types.

              I don’t know any good doctors I could recommend…JUST KIDDING!

  100. says

    Appreciate the article and have been waiting for you to write more on RS, but I was hoping you’d also give us your take on Mark’s response to this article:

    The Link Between Carbs, Gut Microbes, and Colon Cancer

    :in a recent post on his blog:

    Does Resistant Starch Cause Colon Cancer

    This is the part of his blog post that concerns me:

    “Chronic, low levels of butyrate exposure might be inadequate for protection and actually select for cancer cells that are resistant to the inhibitory effects of butyrate. Thus, if early adenomas are exposed to low butyrate levels, they can become butyrate-resistant (malignant) carcinomas if allowed to progress.”

    What is your considered opinion, and recommendation, especially for those of us who are older?

    • says

      A peer reviewed to that study just came out:

      Click on the pdf button and you can hear an interview, you may be able to find full text if you poke around some, too. Hopefully this article will get some good attention!

      From the full-text (hattip Gemma!)

      “Interestingly, the findings of Belcheva et al. suggest that butyrate functions as an oncometabolite, a provocative thought since numerous previous studies have identified butyrate as a tumor-suppressive metabolite (Bultman, 2014). In addition, R5 human microbiome sequencing projects have reported that CRC cases have decreased abundance of butyrate-producing bacteria compared to healthy controls. Furthermore, when butyrate is added to CRC cell lines, it decreases cell proliferation while increasing apoptosis and/or cell differentiation. In fact, butyrate-induced expression of p21 is responsible for the decreased proliferation of HCT116 cells (Archer et al., 1998). Yet, in the ApcMin/+;Msh2 А/А model, Belcheva et al. observed in creased butyrate levels in untreated mice were correlated with decreased expression of p21 (and increased cell proliferation and polyp number) compared to mice treated with antibiotics or provided a low-carbohydrate diet.

      How does one reconcile these seemingly disparate findings? Butyrate is a pleiotropic molecule that functions as an energy source, a histone deacetylase (HDAC) inhibitor, and an agonist of several G protein-coupled receptors. It may thus have different effects depending on the genetic background of the host. In this regard, ApcMin/+; Msh2 А/А tumor initiation does not necessarily involve dysregulated b-catenin expression, which is different from the more commonly studied ApcMin/+ and azoxymethane (AOM) models (Kongkanuntn et al., 1999). Furthermore, MSH2 deficiency results in a mutator phenotype that magnifies the somatic genetic background differences in the tumor (Reitmair et al., 1997).

      It is worth noting that this is not the first instance of a ‘‘butyrate paradox.’’ Butyrate has long been known to have differential effects on normal versus cancerous colonocytes, and only recently has this been addressed. Due to the Warburg effect, butyrate is metabolized by cancerous colonocytes to a lesser extent and therefore accumulates as an HDAC inhibitor (Donohoe et al., 2012). Similarly, butyrate may have heterogeneous effects on tumorigenesis depending on host genetic background, the presence of other bacterial metabolites such as an omega-3 fatty acid (docosahexaenoic acid), which synergizes with butyrate to induce colonocyte apoptosis (Kolar et al., 2007), and whether it is exerting a direct effect on the tumor (cell autonomous) versus non-cell-autonomous effects such as regulating mucosal immune cell activity as mentioned above.

      Therefore, although the current study contributes to our understanding of the interplay between diet, microbes, and CRC, the role of butyrate in cancer protection/promotion will still require further investigation. Altering microbial activities through dietary manipulation represents an exciting means to harness the microbiome and influence health and disease states. Whether dietary manipulation could be used effectively to preserve homeostatic functions afforded by microbiota while attenuating its potential pathological effects is still an open question, and more research would be necessary before this strategy becomes a reality.”

  101. penelope says

    So I’m wondering how much cooled rice (eg sushi) for 10g of RS. I tried to read the paper but info not easily accessible.

    • says

      Rice is a pretty poor source of RS, sadly, and it is very type specific. The sticky rice used in sushi has the least of all rice, probably 1g per cup! Parboiled white rice can have 5g or more per cup. The colored rices (brown, black, red) seem to have more, but also other antioxidants and nutrients than plain white rice.

      If you eat a lot of rice, I’d recommend finding black rice…it’s absolutely delicious! If you are eating sushi just for the RS, it’s not so great, but sushi with rice, seaweed and raw fish is a ‘superfood’ combo in my opinion.

      • John Es says

        I spent a lot of time at various ethnic markets around my town trying to find some high-amylose, non-GMO, parboiled rice. No dice.

        I’m using Trader Joe’s organic basmati.

      • says

        Lotus Foods line of rice (Lotus Foods dot com) is good for a diverse selection of rice — I love the Jade Pearl one, and also Volcano rice, literally grown on the side of a big volcano.

  102. Boundless says

    > … you may need to consider working with a
    > healthcare practitioner to establish a more
    > balanced gut microbiome through the use of
    > herbal antimicrobials and probiotics before
    > adding RS or other prebiotics.

    This needed to be a bit more than a nearly offhand closing remark.

    RS is food for your gut flora. Thanks to modern diets full of gut antogonists (antibiotics, wheat, perhaps glyphosate uptake, and high glycemic foods generally), many people have deficient populations or adverse populations.

    I suspect that “take a quality probiotic when starting RS” needs to be routine advice. Probiotics are the bugs you’re trying to feed.

    What’s a quality PB? Well, if it’s on a room temperature store shelf, and is cheap, it’s probably not. Common retail PBs had insufficient CFUs of a poor spectrum of species at preparation, and may even be contaminated. But it hardly matters, because they’ve been mostly dead all day. You can tell by the usual laughable disclaimer “potency guaranteed at time of preparation”.

    It is possible to formulate a quality PB with a decent room temp shelf life, but your best bet may be found in the pharmacy fridge or store cooler shelves (or mail order where shipped in ice packs).

    • says

      I think it makes sense, ancestrally speaking, to aim for 20-40g per day of RS. If you were eating raw tubers and sedge nuts as our early ancestors did, this would have been no problem.

      The best way to incorporate high RS foods into your diet is to precook potatoes, rice and beans. Store in fridge or freezer until ready to eat. You can reheat, RS will remain (long story).

      With these foods, you will get about 5-10g of RS per cup of food eaten. If you are good at math, you’ll quickly figure out this ends up being a lot of carb calories, too. So, as a stop gap, use raw potato starch in a smoothie or mixed with yogurt. In fact, as I’m writing this, I’m drinking a big glass of freshly juiced, somewhat dirty, carrots from my garden mixed with 3TBS of potato starch! Probiotics and prebiotics!

      Here’s a typical day:

      1 slightly green banana, green on the tips – 10g RS
      1 very small, raw potato, munched on while peeling potatoes to cook – 10g RS
      1/2 cup of rice and 1/2 cup of beans with dinner – 7gRS

      That’s 27g, roughly, from food. Add a TBS of raw starch later and you are well in the range.

      Other tricks – green plantains (sliced thin and dehydrated), nuts such as pistachios and cashews.

      As you get into the rabbit hole of RS, you find exact measurements are unknown and not listed very well anywhere. To increase RS in starchy foods, cook and cool. To get a gigantic dose with few calories/carbs, use raw potato starch or raw potato, green banana, green plantains.

      Nuts have RS…how much seems to vary, but they are a great snack and have several gut microbe boosting benefits.

      Hope this helps!

      • Sam says

        I’d like to increase my RS4 intake, but the problem is that I can’t stand cold or lukewarm food that is normally eaten hot. I like my potatoes and rice piping hot. Is the 130 degree figure here in Fahrenheit? And how far beyond 130 can I go without losing all the RS3?

          • says

            130 deg F will destroy RS2, raw starch granules. RS3, formed from cooked and cooled starches, remains intact during reheating up to 350-400 degrees after which the crystallized bonds melt.

            The RS3 can actually ‘grow’ if a dry-heat method of reheating is employed, such as stir-frying. RS3 is all about ‘staling’. As moisture is driven out, the RS3 bonds become stronger and more RS is formed.

            To reheat rice and potatoes, my favorite way is to quickly stir-fry in coconut oil or animal fat. Probably worst methods are by steaming or microwaving.

            BUT, no matter how you reheat, the differences aren’t all that huge. For instance, potatoes stir-fried may end up with an RS content of 10% and if boiled and mashed, 7-8%.

            • Lucas says


              Thanks very much for the follow up answer to the 130 degrees issue.

              Could you edit the article with this info?

              The way it currently reads it sounds like any (re)heat over 130 destroys the RS3.


              • Tim Steele says

                I just looked at the cite used by Dr. Nett for that discussion. The study linked is a really good one and has a great discussion on retrograded starch.

                It says at one point:

                “It is worth emphasizing that in order to undergo rehydration the products of amylose retrogradation must be heated at temperatures over 120°C, whereas those of amylopectin retrogradation require
                temperatures slightly over 60°C”

                I never realized there was a difference here. Some starch will lose retrograded RS when heated about 248 deg F and some will lose it above 140 deg F. According to this article.

                I guess with high amylose products, ie. Hi-Maize, the upper limit is valid, but for foods that have a large proportion of amylopectin the lower should be observed…interesting!

                Later in the paper it states:

                “Amylopectin is also capable of retrogradation, however
                in its case retrogradation is a long-term process requiring
                several to a dozen or so days of starch paste storage at an
                appropriate temperature. The process is more efficient
                when the starch paste is cooled and heated several times.
                Retrogradation of amylopectin results in the formation of
                crystalline structures built of chains with a polymerization
                degree ranging from 6 to over 50. Temperature of their dis-
                solution ranges from 30° to 80°C, depending on the botani-
                cal origin of starch and conditions of the retrogradation

                Did you follow that?


                This paper shows that potatoes, rice, corn and wheat all have about 20% amylose:80% amylopectin.

                As we now know that amylopectin is harder to retrograde and quicker to dissolve, I think we can assume that most RS3 in the foods we eat is formed from the amylose portion.

                So, I would say that the article is correct. Don’t heat RS3 over 130 degrees F if you want to keep all of it’s resistance. High amylose starch products can be safely heated up to 248 degrees F, however.


                I learn new things every day!

                I just looked at a study I had ( it states:

                “….the main RS, consisted of retrograded amylose … with a melting temperature of 150 °C…”

                This is probably the source of the error. I will be going with the lower temperature from now on to be on the safe side. Still, reheating by quickly frying in hot oil has been shown to preserve the most RS3. Probably because the bulk of it is not heated above 130, or because amylose is actually the prevalent starch in RS3 products..

                Maybe the advice should be ‘gently or quickly reheated being careful not to exceed 130 degrees.’

                But if you mess this step up, you are probably still OK as most of the RS3 was from amylose unless you took active steps to heat and cool the starchy food several times.

                Confused? So is the whole world…this is complicated stuff, man!

                • Lucas says


                  Thank you for the extremely detailed reply.

                  I think I followed everything you laid out, but I also think this topic deserves further exploration.

                  So Fried Rice is still good for RS3 preservation (at relatively lower heats)

                  What about beans? Lentils? If I make lentils, or stew w/ beans and reheat in a pan, how in the world am I supposed to know if I am heating them above 130 or not? Use a food thermometer everytime I warm up leftovers?

                  Would really love to see a detailed and expanded blog post on this on your site or Richard’s. (and maybe a section in the book :)

                  I’m just worried myself and a lot of people are losing a lot of the RS and potential benefits they think they are getting – this information seems to change a lot of recommendations.

                  Thanks again!

                • Tim Steele says

                  Hey, yeah, it’s not really very intuitive or user friendly, I know. That’s mostly why I jump into threads like this.

                  The actual, exact RS content of real food is extremely difficult to measure and that’s why it won’t be on a food label unless it’s RS placed there on purpose.

                  The reason I like potato starch is because it is a known quantity and easy to dose accurately and repeatably.

                  There are some absolutes that make getting and using RS easier:

                  – Green bananas and raw potatoes are a great source of RS2.

                  – Potato starch and banana flour are great sources of RS2.

                  – Cooked and cooled beans, rice, potatoes, yams, and plantains are great sources of RS3. OK to reheat. Exact amount is impossible to determine.

                  – The average intake of RS in the US and most other countries is well under 10g per day.

                  – 20-40g/day is an amount of RS shown to create a better microflora in numerous studies.

                  – RS2 alone is not advised for one’s sole fiber source…better to also include RS3 and as many other fibers as you can get from real foods. Supplement sparingly if at all.

                  – Using potato starch to bridge a gap in a lowish fiber diet is perfectly fine if you can tolerate it.

                  – If you can’t tolerate PS, use banana flour or inulin.

                  – Someday someone will sell starches labelled with their RS content. Until then, do the best you can. It’s nothing to lose sleep over.

                  – And finally, we learn new things about RS and the biome every single day. Until we know everything, we just do the best we can.

        • says

          Great question! Here’s the scoop:

          The retrograding of readily digestible (cooked) starch begins at about 50 deg F and proceeds down to about 10 deg F. The formation of retrograded RS (RS3) is also time dependent.

          About 75% of the RS3 will be formed by chilling to 40 degrees for 8 hours, ie. ‘overnight in the fridge’. Further lowering of temperature and longer time in cold storage will eke out another 25%. The biggest bang for the buck is ‘overnight in the fridge.’

          I like to make big batches of rice, beans, and potatoes. I store potatoes in the fridge for up to a week or so as they don’t freeze well. Rice and beans freeze well, so I store these in the freezer.

          Preparing in this method is a huge time saver and makes fixing bean/rice/spud dishes much quicker than preparing from fresh each night. It’s also more ‘ancestral’ if you think about it, cooked foods weren’t prepared ‘on-demand’ until the last hundred years or so. Leftovers are good food!

          • sheila says

            Hi tim.
            Can i just say i am in awe of your mind and the knowledge you have. I am so impressed with the information you have and how you are helping all of these people by answering their questions.
            Amazing job.

      • Gillian says

        I have been making a GF bread in which I have substituted part of the GF flour for tapioca starch, banana flour and ground flax seed, does this mean that I have been getting RS without even knowing it? I allow myself I slice of this bread every day but I usually toast it, would it be better for RS to have it untoasted? I have autoimmune thyroiditis, gluten intolerance and a candida problem and keep to a very low carb diet and take probiotics.

    • says

      Per my potato salad comment above, here is the best-ever potato salad recipe, from my Grandma with my own twist:

      Grandma Strickholm’s Potato Salad

      Take a bunch of potatoes. She used brown-skinned, I tend to mix it up.

      Wash them. DO NOT peel them. Cut them in quarters or sixths.

      Dump into a huge pot of water, salt (1 T.?), and boil away. When the potato pieces (which will seem pretty large still) are just barely cooked in the center.

      To check for doneness, take out a representative piece from the pot, and pierce it with a knife and fork. It should feel firm but not hard. The outside peels will be coming off a bit.

      Drain in a colander thoroughly, shaking a few times. It’s important to get out all the water, and to do it fast. Don’t leave the colander sitting in the sink for a half-hour, or this recipe won’t work.

      Put the potatoes back in the pot, or use a bowl (Grandma always used the big heavy pot she boiled the potatoes in, which helped give the potatoes the slowest-possible cool-down).

      Pour 1/4 – 1/2 cup of fresh-squeezed lemon juice. (Oh yeah, prep that before you boil the potatoes!) Just do it — trust! Stir carefully a few times. Set aside to cool. I just throw a dish towel over the whole shabang.

      The idea is, the potatoes continue to cook from their own heat for a little while, and absorb the lemon juice and aroma.

      Once the potatoes are cool enough to the touch, take each piece and cut it into smaller chunks. Grandma still left it really chunky. There may be some lemon juice (or a lot) left in the pot. That’s as it should be. You can either drain it off and add back in to your taste, or just leave it in the pot for the potato salad — what Grandma does and I do.

      Stir in mayonnaise (paleo or Grandma’s fave, Hellman’s), until all potatoes are covered. Then stir in salt, pepper, and minced chives.

      My additions: I also stir in minced red onion or Maui sweet onion, some flat-leaf chopped parsley, and roughly chopped hard-boiled eggs, at the very, very end so they mostly remain intact chopped pieces.

      It may look soupy. Don’t worry. Turn the whole thing from the pot into a big bowl, cover well, and refrigerate overnight. You may have to stir once or twice the next day, but it should be just about perfect. Enjoy!

  103. Tony Adams says

    A great article and discussion.
    To make potatoes more palatable does potato salad ( potatoes cooked then cooled) still offer RS benefits?

      • says

        OMG I seriously LOVE potato salad! My grandma made the best potato salad, and I’ve subsequently added a few twists of my own (hard-boiled eggs, fresh flat-leaf parsley). I’ve missed it greatly since entering the paleo world. I think I can pull it off with the paleo mayonnaise in the WellFed2 cookbook.

        • Paleophil says

          Yes, good news, potato salad appears to be super-Paleo in the original sense of Paleo that Dr. Boyd Eaton hypothesized–foods that humans are biologically well adapted to. YMMV

  104. Kat says

    I keep trying to take RS in potato starch form but the gas and bloating is bad and since I have FODMAPS intolerance and have been unable to heal my gut I wonder if I should keep persisting.

    • Amy Nett says

      Hi Kat,

      Your continued gas and bloating, along with FODMAPs intolerance suggest an underlying dysbiosis that may respond better to a period without RS, or other prebiotics. I would not suggest you persist taking the RS, as RS may be feeding the pathogenic bacteria just as much, or more, than the beneficial bacteria. If possible, you may want to consider working with a health practitioner for further GI testing and possible treatment with herbal antimicrobials.

      • raphaels7 says


        You respond to Kat by saying “RS may be feeding the pathogenic bacteria just as much, or more, than the beneficial bacteria” yet your article says “Resistant starch selectively stimulates the good bacteria in our intestines, helping to maintain a healthy balance of bacteria (7)”.

        There is always nuance but how do you reconcile this?

        I tried to follow reference 7 but it is pay-walled. Could you please provide the full-text? Alternatively, would you mind further detailing their findings? Thanks.

        The variation in response to RS is not surprising given a little thought:
        – More people than not do not eat normal amounts of fibrous vegetables and so introducing RS is expected to be more beneficial than not, most of the time.
        – OTOH, a lot of people have dysbiotic guts and unsurprisingly, a substantial number of people cannot tolerate RS or other fibres (or don’t see the promised improvements).

        With this in mind & considering the wide, diverse range of microbes fermenting sugars into butyrate (& other organic acids), are we currently in the position to explain RS’s supposed ‘feed selectivity’?

        I think not.

        Regardless, I have 2 bags of Bob’s RedMill Unmodified PS sitting in my fridge waiting to make its entrance in my N=1.

        • Amy Nett says


          Yes, in general RS does primarily feed and encourage a few specific strains of beneficial bacteria. However, this must be taken in the context of a healthy gut environment. If a patient has severe dysbiosis, there may be too few of the beneficial bacteria to ferment the RS, and it may then be fermented by more pathogenic strains of bacteria. If RS is not well tolerated, it suggests underlying dysbiosis that should be treated prior to adding RS to the diet.

          Reference 7 is a 15 page review article, and I included that reference because it points to a few different studies looking at how RS changes the gut microbiome, though acknowledges that further advances in analytical techniques with subsequent further studies will contribute to more fully characterizing the potential changes of the microbiome. That said, several studies do suggest that RS particularly supports certain beneficial strains such as Bifidobacter and Lactobacilli. Here’s an additional reference that you should be able to access at no cost with some more specific information on RS and specific bacterial species:

          • Paleophil says

            FWIW, I have a dysbiotic gut and tolerated RS from multiple sources rather well, with just a bit of early flatulence at higher intakes. Responses seem to vary greatly between individuals, perhaps due to different species of bacteria populating different guts. There are many different RS sources to choose from, and also other prebiotics, such as the inulin, larch AG, and beta glucan that Tim Steele mentioned, as well as others.

    • Goldfish says

      I had a great deal of gas and bloating when I first tried potato starch, which eventually went away once I started mixing Soil Based Organisms (Prescript Assist) into the PS. There was no improvement until adding the SBOs, though.

      As several people have said, you should also focus as RS3 from cooked and cooled rice, potatoes and beans (but maybe not if you have FODMAP issues, and must be properly soaked and cooked). It is important to get RS3.

      • Goldfish says

        I forgot to say that you need to start slow when you mix Prescript Assist into your PS. Maybe just half or less of a capsule to be on the safe side. The first time I did it I had extremely bad gas.

  105. Amber says

    I appreciate your mentioning that people who may react to nightshades seem to tolerate resistant starch well. Can I assume correctly then that people with autoimmune diseases can safely consume this?

    Like Anne above, I’m interested to know your thoughts about supplementing with resistant starch if you are following the Specific Carbohydrate Diet or GAPS since its premise is to eliminate starches. Do you think adding the resistant starch would be negating the purpose of SCD or GAPS?

    • Amy Nett says

      Hi Amber,

      People with autoimmune diseases can safely consume resistant starch. And some of these people will be able to tolerate unmodified potato starch. However, some people who react adversely to nightshades do not respond well to potato starch, and need to use alternate sources of RS, which may include plantain flour or green banana flour.

      Regarding resistant starch for people following an SCD or GAPS diet, it really depends on why you are choosing to follow that diet, and which foods you tolerate well. Specifically, though many people use the GAPS diet to heal various neurologic, digestive or auto-immune conditions, it is often not required as a life long dietary prescription, and people may eventually be able to reintroduce foods containing RS. Similarly, some people who do well on SCD, are often able to incorporate some “safe starches” (such as plantains, sweet potatoes, parsnips, etc.) after an initial period of healing.

      If you are just starting out with an SCD or GAPS diet to begin healing, then I would not recommend adding RS to your diet, but rather focus on healing your gut and improving the microbiome before adding RS.

      • Amber says


        Thanks for taking the time to respond and for your thoughtful response. I’m glad to see you’ve teamed up with Chris and am looking forward to reading more articles from you.

  106. Anne says

    Would greatly appreciate Dr. Nett or anyone who has an understanding of Celiac to comment on my question.

    How would one introduce such starch that clearly has been show to be pernicious to the small intestine of those afflicted? It is even more of a problem in older Celiac sufferers.

    Dr. Sydney Haas and SCD diet have done significant research to the serious problem when ingesting starch.

    • Amy Nett says

      Hi Anne,

      I think the best approach to introducing resistant starch, particularly in the setting of Celiac disease or other cause of GI distress, is to start very slowly with small amounts of either food sources or supplements. If after a few days of taking a small amount (maybe ⅛ teaspoon) of RS, you have uncomfortable symptoms, that may be a sign of more acute dysbiosis that needs to be addressed before adding RS to your diet.

      Unfortunately, there is no one answer for everyone, and the amount of RS a person can tolerate may change over time. For example, during times of increased life stress, underlying gut symptoms or dysbiosis may be exacerbated, and the person may need to to decrease the amount of RS in the diet.

      Some of the “safe starches” in the SCD contain RS, so it is a matter of experimenting and finding what works best for you.

  107. Mattias says

    Thanks for the very informative article. I was hoping to see the resistant starch content for raw potatoes, but unfortunately this data was unavailable in the research article that was linked, which has also been the case in previous lists that I have viewed (such as the one at Freetheanimal). Has anyone found any RS content for raw potatoes or is there any other way to measure the content per 100 g as in the article?

    I have just considered raw potatoes easier than the cook and cool method and also better than potato starch. Potatoes are quite nutrient and significantly cheaper than potato starch, if you take the 4 tablespoons required to reach 40 g RS per day.

    • says

      I don’t mean to take over, but I just love this subject!

      Here’s a breakdown on raw potatoes:

      Potatoes have roughly 16-20% starch content, the starch is about 80% RS. So 100g of raw potato would have 16-20g of starch or roughly 15g of RS.

      In other words, a 100g raw potato is the equivalent of 2TBS of potato starch.

      When I first started talking about RS, I used to advise eating raw potatoes, but people were aghast at the idea. I have done this myself for years with no problems, and Dr. Davis of Wheat Belly is also advising it now. If eating raw, be sure to peel and remove any green spots/eyes. If you have a nightshade intolerance, you’ll already know not do do this.

      There’s a little talked about chemical found in raw potatoes known as kynurenic acid (KYNA):

      “… KYNA possesses anti-ulcerative properties. Furthermore, it is known that KYNA shows anti-inflammatory properties and antagonizes hypermotility of the intestine in an experimentally induced colon obstruction. KYNA, as an antagonist of NMDA receptors, decreases motility and inflammatory activation in the early phase of acute experimental colitis in rats. Moreover, it has been stated that KYNA decreases proliferation of colon derived cancer cells in vitro, and that its content in the intestinal mucus is increased in patients with diagnosed colon lesions such as adenoma or adenocarcinoma. Finally, it has been shown recently that KYNA possesses antioxidative properties.

      Potatoes contain one of the highest concentrations of KYNA among food. It is worth mentioning that only various kinds of honey contain more KYNA than potatoes.”

      That was from: (hattip Marta)

      • Amy Nett says


        I’ve found your research on RS to be extremely helpful, so thank you very much for adding your comments on this topic!

        • says

          You are quite welcome, hope you didn’t mind me jumping in on the technical RS questions.

          RS is such an amazing topic, seems too simple at first glance, but the studies over the last 30 years and more that come out near daily show it is anything but simple.

          Let me know if you ever have any questions you need help with.

          You are going to love Chris and team…lots of people being helped.

          • Deborah Brackenbury says

            Hello Tim,

            Very interesting information on resistant starch. Thank you for taking the time to address these questions. I’m a sauerkraut maker and I wonder how the RS of raw potatoes would change if grated and fermented with cabbage and beets?

            • says

              I think it might be destroyed. The potato starch granules would become compromised by the pre-digestion from lactic acid bacteria.

              I’d think this would put the digestion resistant qualities in jeopardy.

              I make sauerkraut, too. Just cabbage, though. Also beet kvass…an aquired taste but a great source of free summertime probiotics.

          • elizabeth corcoran says

            so how did our ancestors take in resistant starch? i don’t think they ate bobs red mill potato starch … (:(:

            • says

              FINALLY! Why does it always take so long for this question to get asked? Thank you, Elizabeth.

              Before humans learned to cook, we ate raw tubers (such as yams and sedges), seeds, nuts, and other RS2 containing food sources in great quantity. Then, when we learned to cook, we still ate these same foods, only now we heated some of them up. Cooking ‘back in the day’ wasn’t to short order, it would have been done by heaping tubers on a bed of coals and letting them cook, eaten for days after the fire went out. This created a new RS…RS3. Cooking of native African yams is still done this way by the Hadza as they have for millions of years. These aren’t sweet potatoes with little marshmallows melted on top, these are big, ugly yams that sometimes get over 50 pounds in weight.

              When we left Africa, we sought out starches wherever we went. Cattails throughout Europe, sago palm starch throughout Asia. Where bananas and plantains grew, the greener ones were prized more than the ripe ones. Ripe, yellow bananas attract bugs and go bad fast. Green ones keep longer and don’t attract ants and gnats. When you feed a village with bananas or cassava, you can gather them in mass quantity, peel, mash and pound into a dish known as fufu. Still done today in many parts of Africa and Asia by the name fufu and others–and full of RS.

              As man travelled to America, he encountered corn, beans, squash, cactus, and potatoes. All of these are full of rich fibers and/or RS. Early potato consumption was of the starch, not the potato because wild potatoes are mostly poisonous, the extracted starch not so. Lots of dishes in Peru still revolve around potato starch.

              Also, in Africa at the dawn of Man, was found the tuber of a sedge called Cyperus Esculentus, aka tiger nuts, aka chufa. These were eaten by early man and later cultivated by the Egyptians and Spanish…as they still are today. A wonderful drink called Horchata de Chufa is a raw starch drink consumed widely for eons. Has anyone ever seen that strange drink in a cold mixing tub in a Mexican/Spanish restaurant? Horchata needs to be kept cold and constantly stirred to prevent the starch from settling. Unfortunately, Horchata is made mostly from cheaper rice starch today, but in Spain, Horchata de Chufa still reigns.

              Throughout the history of mankind, we enjoyed resistant starch. Whether by accident, luck or design, it’s undeniable that RS is a big part of our past.

              After we marched out of Africa, the first areas we settled were filled with palms. Palmae is one of the oldest plant families on earth and many early societies developed entire lifestyles in synergy with the various palm species:

              •Date palm (Phoenix dactylifers) – Arabs of the sub-Saharan
              •Palmyra palm (Borassus flabellifer) – Inhabitants of South India
              •Lontar palm (Borassus sundaicus) – Roto islanders of Indonesia
              •Coconut palm (Cocos nucifera) – Indo-Pacific Islanders
              •Oil palm (Elaeis quineens) – West Africans
              •Sago palm (Metroxylon sagu Rottboll) – Malaysians
              •Moriche palm (Mauritia flexuosa) – American Paleo-Indians

              What all of these palms had in common were amazing sources of fiber, particularly resistant starch. For instance, the Sago palm was the main source of subsistence throughout southern Asia until rice was introduced in 2500 BC. The sago palm is an amazing RS factory. The first part of its life it looks like a short, trunkless palm tree, but when it is about 10 years old, it will send up a trunk 20-30 feet tall after which it flowers and dies. The year before it flowers, the large trunk is filled with up to 2000 pounds of easily extracted starch. The starch is unique in that it was easily isolated and dried, and when cooked and cooled, retrogrades into one of the most stable RS3 sources on the planet. Products made from sago starch can be stored for exceptionally long periods and helped the seafaring Malaysians travel far and wide throughout the Malay Archipelago. To this day, 25-40,000 tons of sago products are exported annually from Malaysia to the rest of the world.

              One of the best sources of RS2 comes from the mountainsides of Asia.

              Dioscorea opposita, also known as Nagaimo, Japanese Mountain yam, Chinese yam, and Korean yam. It is often used in the Japanese noodle dish tororo udon/soba and as a binding agent in the batter of okonomiyaki. The grated nagaimo is known as tororo (in Japanese). In tororo udon/soba, the tororo is mixed with other ingredients that typically include tsuyu broth (dashi), wasabi, and green onions. Also eaten in China, Japan, Vietnam, Korea and the Philippines.

              Raw Chinese yam (Dioscorea opposita) is an excellent source of RS.

              “We examined the effects of raw Chinese yam (Dioscorea opposita), containing resistant starch (RS), on lipid metabolism and cecal fermentation in rats. Raw yam (RY) and boiled yam (BY) contained 33.9% and 6.9% RS, respectively…These results suggest raw yam is effective as a source of RS and facilitates production of short chain fatty acid (SCFA), especially butyrate”

              Our past is filled with ample consumption of RS2, raw starch granules:

              There were also societies that utilized isolated, raw starches (RS2) in a variety of clever, tasty, and interesting ways, but never as a main source of calories and nourishment.

              •Horchata de Chufa, a tiger nut starch drink that is still enjoyed by many around the world even today;
              •Fufu, a starchy dough made from cassava root eaten in Africa;
              •Chicha, similar to Horchata de Chufa but made with corn
              •Chuno, a dehydrated potato staple of the Andes
              •Tororo, made of the Asian yam Dioscorea opposita, often eaten with Natto
              •Nuts and Seeds, probably every single culture in the history of mankind has enjoyed munching on raw nuts and seeds. Sunflower seeds, pumpkin seeds, chia, flax, and all manner of tree and ground nuts are universally enjoyed by people around the world and contribute to a healthy gut

              Additionally, much evidence of RS3 consumption abounds:

              •Yam cakes
              •Dried, cooked tubers (ie. potato chips)

              It may be the “leftovers” that have given us our biggest supply of RS3 over the years. People living in so-called “Blue Zones” known for tremendous longevity are known to subsist on meager rations of leftover pasta and legumes.

              Not that I’ve given it much thought…

                • says

                  Bah! Just a bunch of wikipedia regurg…

                  This knowledge has been around for 30+ years. I’m just digging it up.

                  Read this statement by the World Health Organization:

                  “One of the major developments in our understanding of the importance of carbohydrates for health in the past twenty years has been the discovery of resistant starch.”

                  — Joint Food and Agricultural Organization of the United Nations/World Health Organization, 1997

              • Analia says

                Thanks Tatertot! I’ve read your info back when at Mark’s Daily Apple and I am so glad you have added more clarification (and history) because I’ve been wondering about it every since then.

                Do cooled sweet potatoes have high amounts of rs? If so, how many grams do I need to get the 15-30 g range? I tried the potato starch for a while and it aggravated my SIBO so I stopped. But I do tolerate yams and sweet potatoes well so I wonder if I can go that route instead.

                • says

                  Sweet potatoes are a funny food, RS wise. They don’t have much when eaten raw, but the starch seems to retrograde at a much higher rate than other starches, so cooked and cooled (optionally reheated) sweet potatoes are a very good choice for your diet.

                  Sweet potato starch noodles are shown to have very high RS when cooked, the highest of all starch-based noodles.

                • Eimear says

                  That’s good to hear re sweet potato noodles- I buy a variety that are made from buckwheat and sweet potato. Looking at the list of foods on Freetheanimal (did you come up with that Tim?), buckwheat seems to be a good source of RS too.

              • Jennie says

                This is fantastic information. I have been a long time taker of PPIs and am very keen to improve my gut health, having some success with raw apple cider before each meal, eating activated seeds and nuts and about to incorporate some of the other RS foods. Fingers crossed!

                • says

                  Are you familiar with the SCD and/or GAPS diets? These diets seem to restrict RS (and other starches) in order to starve out the pathogenic gut bacteria. I have some patients doing very well with the diet, but wonder if/when to introduce RS. I have always wondered about the fact that these diets starve out the pathogens and most likely also the good bacteria – or at least do not feed them well. I wonder how a person with IBD and doing well on a GAPS type diet would do with some RS. Do you have any idea? Or anyone else?

                • says

                  Jill – Perfect timing! I may have a good answer.

                  Yes, I’m familiar, and not a fan, BUT, some people may need these type of diets until the day comes when we can tailor or microbiota.

                  What I hate about these diets is that people who don’t require them use them. These diets need to be reserved for people that truly cannot digest/ferment certain fibers.

                  For all other people, RS and the Microbe-assessable carbs need to be eaten regularly.

                  I think the only way to transition off GAPS or SCD is by trial and error, or a gut biome test.

                  I will have a blog post up tomorrow showing my uBiome test results and how to look for some key microbes.

                  Without a test, it’s all guesswork.

                  If your patients are doing well on these diets, but can’t tolerate phasing fibers back in, they most likely are missing some key microbes that will only be replaced by fecal transplant. Probiotics don’t contain the right species.

                  Hope that helps!

              • Cathy says

                Tim, excellent! I love reading things like this. In reading older stories especially the Beatrix Potter stories I noticed a canister in the kitchen in one of her illustrations that was marked “sago”. Interesting.

          • Ben Rheault says

            Hi Tim, I’ve followed your work for almost a year now and have been experimenting successfully with PS. It seems like the direction this is heading is in more diversified forms of RS, not just BRM potato starch, and RS3 is piquing my interest. My question is, do you have “optimal” preparation methods for cooked and cooled potatoes? So far I’ve skinned some potatoes, roasted them in medium heat for 1 – 2 hours, then frozen them for 24 hours or more and then added them to my morning smoothie. Can you say what you know about whether this is a good RS3 preparation method? Any feedback or direction would be appreciated.


            • says

              Your method is probably the best for making RS3.

              Just think ‘leftovers’.

              No sense sweating it too much, just make leftover starches a part of your diet plan and you are good to go. I pre-make beans, potatoes, rice and store in fridge or freezer. This is probably the easiest way to do it without getting all orthorexic about it. Eventually the numbers will balance out in your (gut bugs) favor.

              Add to this a slice or two of raw potato now and then, a green banana, and snacking on nuts and seeds, and you have it down perfectly.

              Also, think about expanding your palate to inulin…onions, garlic, leeks, dandelion roots, Jerusalem artichokes as well. Inulin has about exact same effect as RS on gut health, but almost even harder to get from your diet without targeting certain foods.

              Eat plenty of RS and Inulin rich foods, and you are guaranteed to be getting all the other minor fibers you require (pectins, gums, mucilages, etc..).

              Hope that helped! I have a good fiber tab on my blog if you click my name.

              • Duck Dodgers says

                A terrific source of Inulin, and perhaps even some RS (but I’m not really sure) is Jicama. I recently started eating it and it’s pretty awesome. Safe to eat raw and tastes like an Apple but a lot more fiber.


                Pretty easy to find in many supermarkets. I definitely think it’s one of those easy fibrous vegetables that most people overlook. It has a very mild taste, so even picky kids would eat it with a little honey.

              • Ben Rheault says

                Thanks Tim, that’s awesome.

                So it sounds like that’s about as “exact” as I need to be. One more clarification though, I read in one of your other comments a back and forth about reheating temperatures (130 vs 240 or something) and I was wondering if these heat restrictions only apply to the REheating or to the original roasting as well – before the cooling?

                Thanks for suggestions about Inulin! I’ve experimented with adding some NOW inulin powder in with the potato starch, about 1 teaspoon, but haven’t noticed anything particular. As for food sources, do you find it ridiculous I’ve been avoiding onions and garlic because of Dave Asprey’s claim that they reduced his cognitive performance?

                Is Inulin affected by heating the same way as RS? Just wondering if the onions, garlic, leeks and dandelion root should be raw or cooked….

                Thanks again.

                • Tim says

                  I like to think a mixture of raw and cooked onions/garlic/leeks etc.. is the best. Again, don’t sweat it–just include them regularly.

                  I have heard that inulin breaks down at high temp, but then other changes take place that can be beneficial. Just don’t burn/char them.

                  Also, I’ve been told that if you salt crushed, raw garlic it elicits even greater immune response and antiinflammatory activity.

                  As far as initial heating. No real concerns. RS2 melts into regular starch at about 140 degrees. Those temps we talked about are more critical for re-heating. But again, don’t waste too much time over-thinking it…eat leftovers sometimes cold, sometimes cooked in a variety of ways and it will all balance out.

                  Duck – Jicama I can find! I need to try it. It has always mystified me. So just raw? That I can do!

                • Ellen says

                  Raw jicama with some chilli powder, lime juice and salt is delicious. Crisp, crunchy slightly sweet and easy, peasy.

                • Paleophil says

                  Ben R. wrote: “do you find it ridiculous I’ve been avoiding onions and garlic because of Dave Asprey’s claim that they reduced his cognitive performance?”

                  Yup. 😉 Almost as ridiculous as an Irish-American like me mostly avoiding potatoes for years because of Ray Audette and Loren Cordain’s negative claims about them. I thank my lucky stars that I came across Tatertot Tim and a dude with the handle Muhammad Sunshine reporting marvelous benefits from resistant starch. I was quite skeptical at first.

                  Tim, Get going on the jicama, man. I don’t want to have to keep nagging you about that. 😉 Just be sure to get a small, fresh one that doesn’t have dimples that look like air bubbles on it. The bubbles mean it’s overripe, and they get quite bitter when overripe.

                • Ben Rheault says

                  Hey Tim, one more question. What part of the dandelion is the good stuff? You mentioned Dandelion root above but I see you talk about Dandelion greens somewhere else. I was able to find some greens in the local grocery store and cut these up, but they are incredibly bitter. Without the stems seems better, but don’t want to be doing it at all if it’s only the roots that are good!

                  Oh, on your website it specifically says the greens…. So does that include the stems!?

                  Thanks again man,

                • Tim says

                  Ben – All of the dandelion is good. Leaves and roots both full of inulin.

                  But eating it is a different story!

                  I’ve never bought any at the store. In the spring, I find dandelions that have just popped up. All leaves, no flowers or stems. Sometimes you find tightly packed flower buds in the center, but with no stems yet.

                  In this stage, dig them up, root and all. You will find not a hint of bitterness anywhere, the root is actually very sweet.

                  When the flowers start appearing, the bitterness starts. You can still eat the leaves, but the root starts to get bitter, the stems with their milky white sap is extremely bitter. People have been making wine with the flowers forever, and they can also be gathered and eaten, unopened if possible…lots of magic in flower buds: Google Gemmotherapy (that’s your homework) (hattip, Gemma, natch).

                  OK. Raw leaves and roots in early, early spring.

                  Later as they become bitter, or the leaves you find at Safeway. Try this:

                  Wilted Dandelion Salad

                  Fry 2-3 strips of bacon, the fatty stuff. Remove bacon, leave fat in pan. Turn off heat. Toss the dandelion leaves straight into the hot fat, stir fry a bit until wilted. Add a splash of vinegar and maybe a dash of sugar (I use coconut sugar). Toss lightly and serve hot covered in….BACON!

              • Ben Rheault says

                Hey Tim,

                So I finally found some Jerusalem Artichoke in the store today. Any tips on preparation? You like this one better raw or cooked? Now before you say “don’t sweat it” I’m just looking for what your palate likes and not necessarily what the “perfect” scientific way to do them is.


      • Mattias says

        Thanks a lot for your help, I’ll continue with 2 raw potatoes (about 45 g RS then) per day, as well as some vegetables.

      • Kee says

        Hi Tim, I would like to incorporate resistant starch into my husbands diet who has type 2 diabetes with the aim of reversing his gut dysbiosis (the root cause of diabetes).. Since he needs a low carb diet what do you think about the idea of fermenting raw potato in order to get rid of the rest of the digestible blood spiking sugars..? Also are you absolutely certain of the percentage of resistant starch vs digestible starch in raw potato..? Thanks, Kee

        • says

          I think fermenting a raw potato will actually do the opposite of what you want. It will be pre-digested and easier to absorb in the small intestine.

          A raw potato, however, should not spike BG much if any. There is no easily digested component in a raw potato. I once ate one full pound and check BG for 2 hours afterwards at 15 min intervals, there was no more than a 5 pt rise.

          Try it on yourself first, you can use his BG monitor. When you see it does nothing to you, try it on him.

          Yes, I’m absolutely sure on the percentages. For the most starch content, chose a baking potato (Russet). But the RS percentage of all potato starch is exactly the same. 64% when measured mechanically by an official fiber lab, 80% when measured in a live person.

      • Gail says

        Incredible! I’m glad the issue of eating raw potatoes came up and to see Tim’s response. I used to eat raw potatoes as a child – my grandmother used to hand me pieces while she was slicing them for cooking. I am pleased to start eating the raw potatoes again knowing the benefits of RS, Thanks again, Tim!

      • says

        For all you raw potato lovers out there, there is a Japanese food comprised primarily of raw grated potato. Personally I find it disgusting, but my Japanese friends love it!

        Also, I’d like to hear more about the high levels of KPNA in honey that was mentioned.

        Good discussion, people!

        • says

          KYNA in honey:

          “The highest concentration of KYNA was obtained from honeybee products’ samples, propolis (9.6 nmol/g), honey (1.0-4.8 nmol/g) and bee pollen (3.4 nmol/g).”


          “Kynurenic acid (KYNA) is an endogenous antagonist of ionotropic glutamate receptors and the alpha 7 nicotinic acetylcholine receptor, showing anticonvulsant and neuroprotective activity.”

          This is all ‘brain stuff’. Just another tiny micronutrient that doesn’t factor into our Carb-Fat-Protein view of the world.

          I doubt this means you should eat a gallon of honey every day, but it does indicate that honey has some magic hidden in its sticky sweetness.

          • Gemma says

            Interesting to note that this anti-inflammatory kynurenic acid (KYNA) is found not only in potatoes and honey, but also:
            “in some herbs regarded as herbal medicines when it comes to the digestive system: St. John’s wort, nettle leaf, birch leaf, elderberry flower, and peppermint leaf.”

            “KYNA was also found in leaves, flowers, and roots of medicinal herbs: dandelion, common nettle and greater celandine.”


            So potatoes are really in a good company!

            I would love to see or discover more research papers on the effects of these KYNA rich foods and herbs in inflammatory and other disease conditions and their possible relation to tryptophan, serotonin and melatonin metabolism (KYNA is a tryptophan metabolite).

            • says

              These minor constituents interest me way more than the total carbs! Even the so-called toxins (saponins, solanine and choconine) seem to have human health protective qualities!

        • Tami says

          I LOVE the raw grated Japanese yam(?) called either Nagaimo or Yamaimo. Grated it’s called tororo as Tim mentioned in one of his comments. When grated it gets super slimy. Put it over rice and top with a little soy sauce, sliced green onions and crushed nori. Then slurp it up with some chopsticks! You can also top it with minced umeboshi (Japanese salted plum) or sliced shiso leaves. It’s addictive. Really!

      • Susie says

        I love raw potato and am wondering what size of potato in inches or ounces would be the equivalent to 100 g. Thanks.

        • says

          100g = 3.5 oz, or potatoes that would be 4 or 5 to the pound. That’s a very small potato, a little bigger than a golfball. Play around with the scales next time you are at the supermarket, they won’t get mad at you!

      • Hemming says

        Hi Tim,

        Thanks a lot for sharing all of your wisdom – its really appreciated!

        Do you have a link to studies showing the range of RS2 in raw potatoes?
        If we assume its in the range of 60-80% of the starch and the starch content is 15-20g/100g would that really mean that I can subtract 9-16g from the carb count as it will not be digested? If that’s the case then potatoes are almost a low carb food.
        I can easily eat 500g of raw potatoes for dinner but that would actually only give me around 30g of usable carbs? Can it really be true? :)

        • says

 shows 500g of potato to be 105g carbs w/11g of fiber. That’s eaten hot. Cool it and you’ll get an additional 25-50g of RS. The RS and fiber can be subtracted from total carbs to get a net carb value of 44-69g. Plus 12g or protein!

        • Tim says

          CalorieKing shows 500g of cooked potato to have 105g carbs and 7g of fiber. Cool it down over night in the fridge and you can add 25-50g of RS to that. Subtract the fiber and RS and you’ll see approximately 45-70 net carbs.

          • Hemming says

            Thanks Tim!

            But if I’m eating the potatoes raw and up to 80% is RS then I’m possibly only getting 20-30g of digestible carbs, right?
            That said, even when cooked and cooled its still a lot of RS and not much digestible carbs. Moreover, cold potatoes are an underappreciated food :) (even though you can reheat them without losing much RS).

      • Duck Dodgers says

        I’ll just add a word of caution on raw potatoes.

        I don’t have a nightshade intolerance, but a few months ago I ate half of a raw potato that was flooded with solanine and paid dearly for it. It was not fun. 6 hours after ingestion I felt like I had been poisoned and needed a good dose of activated charcoal. Luckily, things settled down after that.

        If the peels have green under them — from either prolonged or improper storage — it’s usually best to just toss the potato (although, you could safely extract potato starch out of it). Once the green and eyes are there, solanine can flood into the potato flesh, so peeling those green areas will do nothing.

        Secondly, if you notice a burning sensation in the back of your throat as you chew on the raw potato, that’s the solanine/glycoalkalids you’re sensing. It’s your body telling you that something isn’t right. Spit it out and save yourself the potential trauma.

        As Tim points out, raw (fresh) potatoes are great, if tolerated. And trace amounts of glycoalkaloid nightshade toxins may in fact be very good for you, as they are believed to offer anti-inflammatory, hypocholesterol, anti-fungal, anti-bacterial, anti-cancer and anti-viral properties, as this study explains. But, That same paper also offers a stern warning on the dangers and complications when too many glycoalkaloids are consumed. It’s not all fun and games. The dose makes the poison. And sometimes glycoalkaloid issues — such as joint pain — can take weeks to develop, and they can take weeks to clear.

        So, please use caution. Eating raw potatoes is not ideal for everyone.

        I will say that one’s ability to consume raw potatoes is likely tied to their gut health. Gut bacteria can help metabolize glycoalkaloids (perhaps into some beneficial metabolites). Therefore, some people may gain or lose their nightshade tolerance over depending on the state of their gut health.

        And, for those who enjoy a Paleo perspective on eating raw potatoes, ancient Andean Indians did in fact eat raw potatoes with mud dressings and dirt to absorb excess glycoalkaloids. Though, it’s worth pointing out that their potatoes likely had far more glycoalkaloids than our wussy domesticated potatoes do. :)

  108. says

    Dr. Nett – I’m a fan already! Great article, this is exactly why I have been talking non-stop about RS for nearly two years now.

    Alice – Just my take, but if you experienced headaches and insomnia after eating a bit of raw starch, you have serious gut dysbiosis whether you were feeling it or not. Everyone should be able to tolerate RS, it’s a foundational fiber, one we evolved on, and the fiber found most abundantly in nature, yet sorely lacking from our diets.

    Initially, gas and bloating may be a concern for most people with relatively good guts, but dose and time will clear this up. Headaches, joint pain, diarrhea, insomnia, and other major symptoms are all indicative of poor gut microflora.

    I’ve come to the belief that 4TBS is a bit much, and 1-2TBS plus lots of other fiber is better.

    • Margaret says

      Thanks Tim. I get insomnia and restless legs syndrome from RS, but also from eating too many high FODMAP foods, so I know SIBO is a big issue for me at the moment.
      In the meantime, can I get butyrate from consuming ghee? Is it as beneficial to the colon?

      • says

        Sorry, butyrate for the colon has to come from fiber-degrading bacteria. Lots of studies show that dietary butyrate doesn’t make it to the large intestine, it’s all absorbed as fat in the small intestine. The only thing that comes close is butyrate enemas or specially coated pills, but I doubt you can find these at Wal-Mart.

        Follow Chris’s advice for removing SIBO, and keep trying! All fiber is a FODMAP. People get too wrapped around the term and think they need to avoid them all. If you are forming turds, you are ingesting a FODMAP of some type. You maybe need to avoid allergens more than FODMAPS (dairy, wheat, eggs, nuts, shellfish, etc…). Find a way to eat that keeps you regular and feeling good! Avoiding foods until the list is four feet long is not the right approach. Elimination diets are great to figure yourself out.

      • Janknitz says

        If you aren’t tolerating FODMAPs, try cooked and cooled white rice. It has more “non-resistant starch” than pure raw potato starch, but I’m finding that it does not raise my blood glucose significantly and does not knock me out of ketosis. Test, test, test, as your mileage may vary.

        Rice pasta is essentially retrograded already, and I am tolerating that well. Make sure there’s no wheat flour in the ingredients, tapioca flour is OK, too.

    • Beatrix says

      Thank you Tim, is adapting of gut flora also one of the reasons one gets gas after ingesting dried fruit, which I love?

      • says

        Possibly. Could also be from fructose malabsorption. I used to have issues with that–pears were the worst. Since starting RS almost 2 years ago, I have no more problems in this area.

        Dried fruits also contain super high levels of sulfur, usually. Some people have issues from sulfur.

      • says

        Timing makes no difference from what I’ve seen. Possibly taking it in two doses during the day might have benefits over one big dose. I usually just do one big dose. Once it hits the large intestine, most fermentation of RS is done in the cecum and from there it slowly spreads out. One reason for taking RS alongside another fiber, like psyllium husk as mentioned by Dr. Nett, is that the fermentation products are more evenly spread throughout the colon.

        Until very precise studies are done, just do it however you feel comfortable.

  109. Alice says

    What about people who experience headaches and even insomnia when using potato starch? I had no GI distress whatsoever, but I had to stop it because of the aforementioned effects.

    • Lauri Salmi says

      Same for me. I have bad leaky gut, shady bacteria and inflamed intestines. Potato starch causes me hypoglycemia, insomnia, headaches and overall weakness.

      It would be very interesting to hear opinions and experiences on how to proceed, when RS and prebiotics cause bad side effects. Chris said on a podcast that prebiotics are absolutely crucial in restoring healthy gut flora. Will the good guys take over if RS is consumed long-term or will the situation just get worse?

      • Burbank Court says

        About 6 months ago, I was diagnosed with leaky gut, etc, resulting from some back-to-back antibiotics. I started probiotics, made some dietary changes, and began making progress, with side effects that after some research, I suspected the hang up was the lab-created prebiotics included in the probiotics. After a few experiments and some further reading, I switched to a probiotic that did not contain any prebiotics, inulin, fructo-stuff – and I was back on track and making good progress. I’m doing well now. From what I’ve read, once the digestive system is healed and functioning efficiently with a good population, prebiotics might very well be easily added without any repercussions. But I’ve also read that for some people, prebiotics – in the form of chemically made prebiotics under the name of fructo-stuff – will not ever be tolerated well. Also – this potato starch? I called Bob’s Red Mill and I’m not so sure it is a good thing. They don’t sell that starch for people to eat straight out of the bag. They used high starch potatoes, but they use a variety – including the high starch floury type potato which is NOT high in resistant starch, only amylase – which most of the potatoes they use are. And, they are NOT organically grown potatoes. They buy from conventional farms – those farms that use pesticides. And, remember that potatoes are on the “Dirty Dozen” list. So….

  110. Karen says

    So, you could add in potato starch on a ketogenic diet? The nutrition label says the total carbohydrates are 10, with no listed fiber.

      • Dave says

        My understanding is that potato starch as Chris points out is cooked and cooled in order form resistant starch.

      • David says


        Then if I understand this right, Bob Mill’s unmodified potato starch will not spike blood insulin, therefor since I am doing Kiefer’s Carb Nite, on VLC days I can eat a couple of tablespoons and the carb amount won’t put me in jeopardy of exceeding 30g of carbs?

      • crispy says

        You aren’t telling us we should eat raw potato starch are you??
        I have used it as a substitute for flour and corn starch in baking , ie cooked

        • says

          What? That’s crazy! Eating raw starch is known as Amylophagia, a mental condition:

          (from Wikipedia)

          “Amylophagia is a condition involving the compulsive consumption of excessive amounts of purified starch. It is a form of pica and is often observed in pregnant women”

          “Amylophagia arises from a combination of biochemical, haematological, psychological, psychopathological and cultural factors. Many say that they are physiologically compelled to eat starch, and starchy things, because they enjoy the taste, texture or smell while others say that it helps relieve stress and makes them feel calmer. It is also believed that it be a result of a nutritional deficiency. Although the cause of Amylophagia is still unknown a number of these factors may contribute to its development.”

          But then again, same Wiki article:

          Health Benefits –
          “In their raw and uncooked form, small quantities of green banana flour, green plantain flour, unmodified potato starch and Hi-maize® resistant starch, are highly concentrated sources of resistant starch — a dietary fiber with strong prebiotic properties. Resistant starches are not digestible by humans and are fermented and metabolized by gut flora into short chain fatty acids, which are well known to offer a wide range of health benefits. Like most dietary fibers, resistant starch consumption has been shown to improve blood sugar, glucose tolerance, insulin-sensitivity and satiety. However, it should be noted that most published studies suggest that consuming more than 50 grams of resistant starch per day offers no additional benefits.”

      • mark a says

        Tim a interesting question, i have eaten raw potatoes off and on all my life, is that a RS? Is it healthy? Or bad idea?

        • BrazilBrad says

          Some traditional cultures still eat roots/tubers lightly roasted (~5 mins) on an open flame, which would mean the interior is still pretty raw and loaded with RS. IMO, this is the closest to how our ancestors likely ate them. I’ve done the same with cassava root on over the gas stove and also cooking thick slices on a George Foreman-like grill. Purposely undercooked them. French fry like taste. Perhaps a bit dryer. I like it. FYI, fresh cassava has much less water content than potatoes and starch breakdown needs a wet cook, so there ya go. Dry cooking starches creates some other additional prebiotics. Paleo man was all over dat.

          • BrazilBrad says

            Some cassava cultivars are fine to eat raw. Others are not and those are the ones used to make cassava starch and flour. And yes, the processing removes the toxins.

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