Intermittent Fasting, Cortisol and Blood Sugar | Chris Kresser
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Intermittent Fasting, Cortisol and Blood Sugar

by Chris Kresser

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There’s been a lot of discussion about the benefits of intermittent fasting (IF) in the paleo community lately. Paul Jaminet mentions it’s role in boosting the immune system in his book, The Perfect Health Diet, and IF can also be helpful for those trying to lose weight and tune their metabolism.

From an evolutionary perspective, intermittent fasting was probably the normal state of affairs. There were no grocery stores, restaurants or convenience stores, and food was not nearly as readily available or easy to come by as it is today. Nor were there watches, schedules, lunch breaks or the kind of structure and routine we have in the modern world. This means it’s likely that our paleo ancestors often did go 12-16 hours between meals on a regular basis, and perhaps had full days when they ate lightly or didn’t eat at all.

So, while I agree that IF is part of our heritage, and that it can be helpful in certain situations, I don’t believe it’s an appropriate strategy for everyone.

Why? Because fasting can elevate cortisol levels.

One of cortisol’s effects is that it raises blood sugar. So, in someone with blood sugar regulation issues, fasting can actually make them worse.

I’ve seen this time and time again with my patients. Almost all of my patients have blood sugar imbalances. And it’s usually not as simple as “high blood sugar” or “low blood sugar”. They often have a combination of both (reactive hypoglycemia), or strange blood sugar patterns that, on the surface, don’t make much sense. These folks aren’t eating a Standard American Diet. Most of them are already on a paleo-type or low-carb diet. Yet they still have blood sugar issues.

In these cases, cortisol dysregulation is almost always the culprit. When these patients try intermittent fasting, their blood sugar control gets worse. I will see fasting blood sugar readings in the 90s and even low 100s, in spite of the fact that they are eating a low-carb, paleo-type diet.

That’s why I don’t recommend intermittent fasting for people with blood sugar regulation problems. Instead, I suggest that they eat every 2-3 hours. This helps to maintain stable blood sugar throughout the day and prevents cortisol and other stress hormones like epinephrine and norepinephrine from getting involved. When my patients that have been fasting and experiencing high blood sugar readings switch to eating this way, their blood sugar numbers almost always normalize.

I don’t think eating every 2-3 hours is “normal” from an evolutionary perspective. But neither is driving in traffic, worrying about your 401k, or staying up until 2:00am on Facebook. The paleo template is there to guide us, but it’s not a set of rules to be followed blindly. This should also be a reminder that there’s no “one size fits all” approach when it comes to healthcare. Successful treatment depends on identifying the underlying mechanisms for each individual and addressing them accordingly.


Join the conversation

  1. Can anybody give me some ideas?
    Ihave gallbladder polyps and need to get them checked every few months as they can turn malignant, have also fatty liver, borderline high cholesterol, BG around 100 and 130 post prandial sometimes 110 even. Overweight 107kg need to be at around 73kg (ideal weight) Viceral fat 15, bodyfat 30%.

    I do intermittant fasting and up to 22hrs but usually round 18hrs and then start eating, I tried keto but failed many times seeing as I have GERD/Hiatal Hernia and so an increase in Fat = reflux hell, I even made keto bread myself as I figured the coconut flout in the bread or almond flour may help to bind the acid, Nope!

    I find that I have little energy whilst in a fasting state in the mornings and afternoon and have energy, thats right … after Ive eaten, and so doing cardio or resistance type exercise whilst fasting would be like climbing a mountain, whereas its easier when I eat. I aslo feel more nervous/anxious in a fasted state and this makes sense, higher cortisol/adrenaline etc cause you are being pushed to find food, or kill, woe betide anybody gets in my way whilst Im driving in the am … this is what I dont like and need to carb up to calm the heck down.

    My idea was to help shrink those polyps by getting my body to get into autophagy and this is achieved (hopefully) after the 15hr period with some cardio help to deplete liver and skeletal muscle stores, I think the increased cortisol is not so bad unless it gets too high, i.e. unless I add insult to injury and do daily coffee enemas, drink coffee and tea then yes I get wired and ratty as hell.
    Im taking serrapeptase, curcumin and vitamins and selenium too.
    in 2000 I slashed my weight by 30kg in 3 months and came off 2 meds, I went back to my old ways and here I am now.
    I did this by eating 3 meals a day drank sugary green tea beverage throughout the day and walked a LOT, didnt eat friut or veg only tiny amount of veg and meat during the day and ate simple carbs like bread and noodles, this totally worked for me at the time but now I have acid reflux and have to be careful with green tea etc as they weaken the sphincter muscle in the stomach and allow acid to reflux, I need to tweak and try that again or combine the two (IF and my China protocol)

    • Please research relationship between H.Pylori bacteria in stomach causing lowered stomach acid/GERD…even triggers morning sickness as bad as hyperemesis gravidarum.
      GERD is dominantly a problem of deficient stomach acid.
      The body is off-loading what it cannot process. It will do that in 2 ways: throw it up, or sudden fast-transit out the back (for those who tend towards that).
      Some Remedies that usually work well: take 1 or 2 Tablespoons of ACV (real apple cider vinegar in water, with each meal; take something that kills bad germs, or controls sudden over-growths of them, like GSE, colloidal silver, or specific antibiotic to kill-back the H.Pylori….usually one serving of GSE (about 10 to 20 drops in water with citrus juice to buffer the bitter taste); or, a couple ounces of a 30 or 45 ppm colloidal silver, does it…one-time serving.).
      Then, take a really good probiotic…one that has a long list of different kinds of them, as well as high colony counts. We’ve often used Garden of Life Ultra, because that one contains at least one kind that helps make vit. K2, so important for overall health benefits.
      Some have successfully only used daily large amounts of same probiotics only, to crowd-out/kill-back overactive h.pylori….that usually translates to 4capsules daily, on empty stomach, about 30 minutes before eating, to give them best head start to establish themselves.
      Pharma has gone to extreme great lengths, over the past approximately 45 years, to relabel certain symptoms as-if those were stand-alone diseases…they aren’t.
      Symptoms indicate underlying root-causes, which the industries governing and directing how medicine is practiced, have increasingly promoted, to very effectively increase profits, among other things. There are other factors, but that’s the worst, as it has been usurious of human behavior weaknesses.
      But you can look up stomach acid deficiency, and those remedies. We’ve used them often, for ourselves, family and friends, as well as non-related patients, with good success rates.

    • Of course there are other triggers which should be better controlled, such as figuring out why the foods consumed are triggering it.
      That can happen due to how the food was grown, what chemical residues are on it, and things like food sensitivities or allergies. …Allergies/sensitivities indicate underlying conditions that need corrected, too…often, it’s related to trace mineral deficiencies…which is how AgriBiz/CAFO grown foods trigger more frequent and worse digestive upsets than if one only ate organically grown foods (real ones, not all the industry faked-organics ).
      Also, how, when, and what one eats, can matter. Eating fast=bad; combining some foods with certain others, can matter.
      Some get relief using sequential eating: eat the stuff more easily digested, first…in this order:
      First simple sugars/starches, then more complex starches, them proteins, last. That order, “primes the system”, so that by the time it gets to digest the proteins, it’s ready to do it. Though some may need to start by only eating one type of food at a sitting, to start retraining the system, for a time.
      Paying attention to maintaining peace and pleasantness while eating, avoid eating when stressed, etc., matter, too.

  2. I usually disagree with what Kriss has to say, but this I have to agree he has some good points.
    Ive been doing I.F. for 6 months to a year and fast for 18 to 22hrs and was pushing for the 23hr mark and one meal a day, Ive noticed when I do go for the one meal I tend to feel sleepy and HAVE to nap afterwards, maybe the insulin spike? This doesnt happen if I eat 3 meals a day.
    Also in the am I do coffee enemas, if I eat its okay as long as I dont drink too many coffees or teas I dont get jittery, but on my fasting days I DO get more nervous, anxious and woe betide you get in my way, whilst driving Im more nervous, kids tantrums seem worse (my reaction to stress is terrible) easier to anger, I have to a ‘ride’ the morning/afternoons and wait for that evening window.
    Now Im thinking its the cortisol that normally rises in the morning, but in a fasted state doesnt adrenaline and other stress chemicals increase to make you move your ass and find food, its no wonder my brain is more stressed, smells are more intense, sounds seem louder, this is all stress for the human body, and I have less energy (duh) to exercise cardio or resistance, whereas if I eat breakfast I have the energy to walk and do some movement.

    • Gerald, I do the same but no such effects. But it is probably due to that I eat a high fat, (saturated and monounsaturated stable fats) diet combined with low carb and low protein. It enables the fat burning BEFORE fasting so that there is no real fuel change, only change from food to body fat. My 5 cents.
      See also Jason Fung!

    • Checked all labs related to iron in body?
      Serum ferritin, CBC, Tibc, etc., together, can show iron levels in blood, as well as stored iron. One can have a CBC in normal limits, but a low ferritin means borderline anemia.
      Automated lab tests’ accuracy DEPEND on the person being decently hydrated, too! An Automated CBC , from a dehydrated person, can show “normal range”, yet, doing a copper sulfate test on a drop of blood, same person, at same time, will reveal anemic….because the automated lab depends on seeing a certain number of blood cells floating in a certain amount of serum.
      If there’s low fluid volume, the machine thinks there’s more blood cells in ratio to serum, than actually exist; but the copper sulfate manual test, is based on a chemical reaction, not a picture, so reveals the anemia when machine cannot.
      I wonder how chronic dehydration might also cause erronious results on other mechanized labs…worse, how many people have been mis-treated, due to this kind of erronious results!?

  3. Dr. Fung wrote this article that discusses how cortisol and other hormones affect our blood sugar. Although Dr. Fung is a proponent of Intermittent Fasting, I read this article as not agreeing with what Kresser wrote. That is, if your *other* blood sugar hormones are not functioning correctly, you can have blood sugar problems.

    “Just before awakening (around 4am), the body secretes higher levels of Growth Hormone, cortisol, glucagon and adrenalin. Together, these are called the counter-regulatory hormones. That is, they counter the blood sugar lowering effects of insulin, meaning that they raise blood sugars. The nocturnal surge of growth hormone is considered the primary cause of the DP.”

    • Thank you for this link. As a type one, I wasn’t undestanding my high bs while IF. Maybe I can snack on cucumbers or seeds to keep me balanced.

  4. All this conflicting information and flip flopping by these medical and nutritional gurus is so confusing and frustrating. I can see how many people can just want to throw their arms up and say “the hell with it all”. As for me, I’m going with what works for me. I feel and look enormously better eating vlc with intermittent fasting. My fasting bg does at times go up but as Kresser himself said in another article, it’s not a cause for concern when you’re in physiological insulin resistance. I’m a believer in Dr Fung’s program and I’m determined that my genetic predisposition will not have it’s way with me as it has with so many of my family members. And so far, so good. I’ve recently come across a few of these anti fasting/low carb cortisol/adrenaline articles and viewpoints which have made me question the low carb/IF/Keto path I’ve been on. And then I’ve researched it more and have found just as many articles from other experts with the opposite viewpoint. So until I find some real science that says some temporary elevation of my cortisol/adrenaline levels is worse than Diabetes, I’m sticking with IF and Keto.

    • I am on vlc and IF. Occ longer term fast. My sugars fluctuate. But overall they are improved. I am quickly down 17lbs and pressing on.

    • My 2 pennies of thought.
      The key to insulin resistance being kept in check after weight loss and IF is weight training and or HIIT. This is key to reversal.

  5. Was wondering if anyone could explain why I get shaky AFTER eating following intermittent fasting? Doing 16:8 or sometimes 20:4. I feel fine before eating then 20 minutes after eating I get that internal shakiness and heart pounding. I am not eating junk and have been very cautious as to was I first consume after a long fast .
    My last A1c was 5.8 down from 5.9 months before but it is stil to high according to my Dr. I have lost about 10 pounds and trying to lose more to get A1c down.
    Anyone have any idea??

    • Are you drinking enough water? Water keeps the hunger down . If this is happing drink soda water too! It really curbs your thirst , and your hunger. Eat celery, carrots , these are water base , if you like tart fruit , bring rhubarb , I love it eating it after cleaning the skins keeping some water in a lunch bag to keep them moisten. Go on Pintrest check out food to eat on intermittent diets with lots of water substances in them , to keep you strong through your fasting .
      I hope it works ! And I hope I can help you out !

      • This is the adrenaline (norepinephrine) he spoke about in the article. I get a similar feeling at times. I finally had my naturopath discover what it was.

        “Eating at 2-3 hour intervals helps to maintain stable blood sugar throughout the day and prevents cortisol and other stress hormones like epinephrine and norepinephrine from getting involved.”

    • Potentially a food intolerance? Gluten makes my heart pound…so I stay away from it now. So does sugar…even dried fruit. So I stay away from that. Food logging helps figure these things out so that might be a good thing to try.

  6. For three weeks I have been intermittent fasting eating within five hours. During this time my blood pressure has been consistently higher than usual, especially in the evenings. My diet has been varied and not necessarily Paleo or low-carb. Chris’ article about cortisol makes sense to me. Maybe I will increase to eating within 8 hours and try to balance my meals better or even try lower carb (I love lima beans and sweet potatoes.) but not zero carb, ugh! I think my body is feeling stressed by not eating 16 or more hours every day. I know I am still a sugar burner and would have to be really strict to start burning fat but I don’t want to take blood pressure meds.

  7. Too bad author doesnt say that usually low carb diets result in increases cortisol.
    Also its very funny how Kriss in another article explains why higher BG on keto is ok beacause its “physiological” and even 110 foesnt hurt but in IF its suddenly dangerous and bad.

    So maybe your patients are insulin resistant cause of fat excess and hypercortisolic because of lack of carbs?

    • Find Dr Jason Fung’s blog. There you can find the explanations to why your assumptions are ill-founded. High Fat diet does not cure insulin resistance but it prevents blood sugar from rising high taking none or less insulin. Intermittent fasting, however, will cure insulin resistance, best when done a few days in a row, weekly. After that, fasting glucose becomes normal again once the liver fat is consumed through the fasts. Then BG remains normal, with or without carbs.

      • Perhaps you (and everyone else lambasting Chris) should follow your own advice and go read Dr. Fung’s latest blog post.
        “A few other notes about the hormonal changes of fasting. Notice that cortisol does go up during fasting. Yes, fasting is a stress to the body and cortisol acts as general activator as well as trying to move glucose out of storage and into the blood. So, if too much cortisol is your problem, then fasting may not be right for you.”

        There is no miracle pull or treatment that is right for everyone. IF is fantastic for many people (I am 3 days into a 7 day water fast as I write this) but I am healthy, have no hormonal dysregulation issues and I check my cbg and ketone levels every morning (50 and 6.4 this morning!) Other people will have very different experiences.

        • To Chris Hastings.
          If you read more you find that Fung saw a problem with high cortisol in ONE single participant. Not a general problem. Do you know about studies showing the cortisol problems to be general? I, for one, at 70 years of age, had no problem to lower my insulin and blood sugar through 5 day-fasts. Fat is not the villain if that is what you are trying to make it out to. It provides energy without blood sugar spikes, just in the same way as energy is provided to us through (short) fasting. Saturated fat is our bodies preferred way to store fat. Probably because saturated fats react the least to oxidants because it is the most stable fat type. It does not get rancid easily as monounsaturated and especially polyunsaturated fats. Meaning also that our brains – made largely by fat – become more resilient to electromagnetic radiation, well known to do its damage by breaking down structural fats. This was measured through an increase of the fat breakdown product malondialdehyde (MDA) in rat brains exposed to mobile phones! The control group had low normal MDA levels. If you keep talking using a mobile to your ear, at least make sure the fat you eat is saturated fat, the safest. We become built of what we eat. A good reason to avoid junk food.
          Common rat trials with “high-fat” chow make rats diabetic, a practical example that has made many researchers fully believe the thesis that “fat causes diabetes”. But only until they find out that part of the chow is sugar, 20%. Without the sugar, the rats won’t eat the chow at all, the manufacturer explained. Finally, since high fat is what we burn during fasting, eating low carb high fat before fasting days means smooth transitions, with low or no hunger. Same fuel, different source. BTW, fasting also clears out old and broken proteins and inflammations in the body, at the same time as the number of stem cells increase, also in older subjects as the number of stem cells determines our healing/repair capabilities. Hence very important that it is easy to commute between feasting and fasting. The high-fat food is key again.

          • You did not comprehend his article..I am one who suffers from high cortisol and IF does NOTHING for me.. however after reading his article I started eating every 2 hours and my blood sugar is now normal.. he said one size does not fit all It obviously fits you but not me or the dozens of others he spoke about…. and I did not get that fat is a villain in his article…

  8. My fasting blood sugar is 300 reduced to 250 but my doctor says I have low blood sugar. I already fainted at work for not eating for more than 5 hours-though I asked the Boss to let me go as I’m
    Not feeling well, she thought I was faking it.

    • You need to change doctor. Fasting blood sugar over 135 is definitely diabetic. Then mix in much more fat like butter, bacon and coconut oil in your meals for several days or best a week BEFORE fasting. Good Luck!
      Also Read Jason Fung’s blog here

      • Dr. Fung fixed me. Haven’t had diabetic meds in almost 6 months and my A1C runs consistently in the low 5’s. Don’t have fatty liver or fatty pancreas anymore either.
        Type 2 is not in remission, it’s gone.

        • Hey there, I’m starting to follow Fungs instructions on fasting cause I’m a newly diagnosed type 2 diabetic and I’m in my 20s. Is there anyway I can talk to you about this, maybe help clear up some confusion I have or gain some encouragement. No one supports my fasting because they don’t know anything about it.

          Thank you

          • Lyn, read more of Fung’s blog posts, the comments and maybe also buy his book, The Obesity Code. It is also available as Kindle.

  9. Could it also be that they are going in and out of ketosis. The ketones are stimulating beta cells causing a hypoglycemic reaction and then the liver kicks in with gluconeogenesis? Never adapting.

    • No ketones at those high bg readings. Fatty liver that will keep pumping out bg until it is “empty”. May take 5 days fasting. Just keep monitoring bg. To be able to fast 5 days you must eat LCHF for at least a week before, then hunger will disappear, almost magic!

  10. Sten, Hi. I am a Type II Diabetic and have stopped insulin since I viewed Dr Jason Fung’s Youtube videos. I have managed to lose 11 kgs weight over the last 7 weeks . I am following the interval fasting method and other than a cup of tea or coffee for breakfast I have my first meal at 13:30 followed bymy 2nd meal at 19:30. While my fasting sugars are now in the 120s my waking up levels are in the 140s and the post prandial 2 hours are also in the 130s.
    My afternoon diet consists of diced vegetable salad with olive oil and lime and vinegar.
    My evening meal consists of either an omlette or vegtable soup or a piece of roast chicken or grilled fish.
    My BMI currently is 25 from a peak of 29.3.
    What should I do to have a better blood sugar profile and also reduce my glucose sensitivity ( If I take a pear or an apple or pomegarnate my postprandials shoot upto 180mg).
    Look forward to your guidance.

  11. I’m 62, have stage 3 adrenal fatigue with reactive hypoglycemia. Taking 20 mg. of hydrocortisone daily. If my blood sugar falls below 105, I’m shaky, confused, depressed, horribly drowsy.
    I have decided to just let my BS stay at 105, since I’m 62. I’m in a comprehensive adrenal repair program, including gut healing, paleo diet, Dr. Wilson’s adrenal repair supplement program (since May 2016), low stress (retired), living simply and low stress lifestyle. I had to stop thyroid meds because they were causing dizziness and depression – Mary Shomon says that’s a sign of too much thyroid medication.

  12. I had a horrible doctor who told me to eat every 2-3 hours paleo and it made me much worse and my blood sugar skyrocketed. It got better once I started adding more carbs and fiber, but my blood sugar is still a little above 100 and I have not lost any weight at all. I have had 15 horrible doctors now (NDs, DCs, integrative and MDs-they all suck)! I was diagnosed with stage 3C advanced adrenal fatigue back in 2014 and it has improved but my blood sugar/insulin is still an issue. I have tried every diet and read every book from every “so called” doctor who wrote a book about something they know nothing about and I can tell you that NONE of their diets/books work at all! so frustrated!

    • I’m EXACTLY the same Stepanie!!! I hear you loud and clear. I’m doing (have done) tried everything under the sun. Been on a paleo diet since 2007, still have elevated cortisol, high blood sugar – especially on waking (called the Dawn Effect), and just cannot lose the 25lbs around my stomach. So frustrating.

      • You will feel better and be warmer by eating more carbs or more in general, but insulin resistance and weight gain will return. It is the insulin resistance in the bottom of it that makes the difference and it has to be lowered long term. Unfortunately too much arbs and too much proteins makes insulin resistance worse long term. The very reason so many people today are where we are, too much fast carbs in the food over too many years builds it up. Once it is low enough whatever extra food we eat makes us warmer. Read how to do on Dr Jason Fung’s blog. Intermittent fasting worked wonders both for my weight and heart disease! Still has slightly elevated morning sugar, 5.5 sometimes. Before it was often 6.5 and over.

        • Sten you’re talking nonsense.
          Kempner provided in the early 70’s the carbohydrates increase insulin sensitivity.
          The issues arise when consuming too much of the wrong types of fat.
          Fat blocks the insulin receptors, inhibiting your bodies ability to pull glucose from the blood.
          High blood-sugars is a symptom, not a cause.

          • Matthew,
            You may want to provide citations to support this view to start a conversation about it. If you would kindly refrain from negative comments that would be appreciated.

            • Thanks Martha, at least a starting point. I usually refrain from responding to insults like those supplied by Matthew. To keep a a decent discussion a decent moderator is required. What happened here?

        • Stem, did you mean to write “too many carbs and too FEW proteins”? This is what I’ve always understood the problem to be.

          • I am reactive hypoglycemic, Hashi’s. I am non-functional if my blood sugar is below 105 – dizzy, depressed, confused, comatose drowsy. I’m 62 – eating autoimmune paleo, exercising, no alcohol, supplementing wisely. I think a life-time of the standard American diet got my body so used to a high level of sugar that it simply will not accept lower than 105, so I’m just going to live with that. I might feel differently if I were younger and had a family to support.

          • Hi Par. No I did not. Both carbs and proteins need to be cut back. Reason Atkins fail after a year or less is that excess proteins are converted to glucose by our livers… , having same net effect as excess carbs. Another reason to cut back proteins is to promote health = maintenance instead of growth, once we have matured. Else we can easier get cancer and not keep our cells clean from breakdown debris. Ron Rosedale has some clarifyng presentations about it (mTor) and Jimmy Moore sorted out his last weight problems by cutting proteins. Intermittently at least down to 0.5 g net protein per kg lean body weight. Yet a 100g beef stake is about 28 g net protein. Cheers!

      • I was prediabetic for years and thought cutting carbs would help. Apparently I did not cut enough and went on to develop T2D. I started a low carb high fat (LCHF) diet combined with moderate exercise and the pounds are melting away. My blood sugar fasting 70-80 range and post meal numbers are below 100. I have had no BG spikes since going LCHF and the “Dawn Effect” disappeared all together. I feel better than I have in years.

        • That exercise is key as you are dumping glycogen and then refilling the body stores instead of it floating around in the blood.

          • Agree that exercise is a key. Yet intermittent fasting IF can have same effect on blood sugar. Of exercises, HIIT is the most effective from two points. 1/ No wear down of body joints as with longer distance running, cycling etc..
            2/ Uses glycogen to build muscles long time after each pass of exercise. Yet IF has another advantage: It triggers autophagy, our bodies only known cellular “garbage collection/recycling” system. Combinations are of course also useful!

            • I’m having a hard time with my fasting blood sugar in morning (dawn phenomenon). I’m working on intermittent fasting and LCHF. From what I understand, IF is more effective since your body is in repair mode. I also really think there is a problem with a malfunctioning liver unable to regulate glucose in the morning. Being 49, I have to realize my body has less control over its hormones, I have less muscle mass, and need to find the appropriate diet and IF to control my blood sugar. Insulin and diabetic drugs are terrible on your body and will try my best.

        • Hi Sharon, that sounds like my case..when I was prediabetic for almost a year I thought I was cutting back and eating right. But unfortunately it wasn’t enough, I’m now a type2 diabetic.. in my opinion our doctors don’t do enough to help us in the right direction until it’s too late..

          • I’m 62, have stage 3 adrenal fatigue with reactive hypoglycemia. Taking 20 mg. of hydrocortisone daily. If my blood sugar falls below 105, I’m shaky, confused, depressed, horribly drowsy.
            I have decided to just let my BS stay at 105, since I’m 62. I’m in a comprehensive adrenal repair program, including gut healing, paleo diet, Dr. Wilson’s adrenal repair supplement program (since May 2016), low stress (retired), living simply and low stress lifestyle, walk 2 miles daily. I had to stop thyroid meds because they were causing dizziness and depression – Mary Shomon says that’s a sign of too much thyroid medication.

            • I need help! My morning blood sugar is always high. 160-200. Will intermittent fasting help me? If so, how long will it take to go down? I don’t know if by fasting I am belong or making it worse?

              • First reduce carbs and increase fats including saturated fats like coconut oil and butter. Bu “fat adapting” fist it is easier to sustain the minimum 3-day water-only fast that can reduce blood sugar into the 70’s and below. Repeat 3 days a week and eat “normal” low carb rest of every week. Plenty green vegetables, organic if possible, when refeeding. Add 1/2 lemon to two quarts of clean water helps to quench all types of cravings during the fast. No limit!
                If fasting more than 2 days, then add bone broth with plenty of salts every day to maintain electrolytes.
                Good Luck!

    • Hello Stephanie
      I can understand why you feel so frustrated and hopeless.
      I don’t blame you.

      Not sure if you’d be interested in another book or not…but it tells you to do things differently in this one. It is written by a Canadian nephrologist in Toronto, Ontario.

      He has a weight management clinic (by physician referral only) as well as a distance management clinic.

      But what I wanted to mention to you is his book which was just published this year called The Obesity Code.
      His name is Dr Jason Fung.

      I am in no way affiliated with him, but I have read his book, seen him on Youtube and subscribe to his email blogs and I think he is telling us what we need to do, which happens to be the opposite of what we have been told for decades.

      The book is a great read.

      Good luck Stephanie!


      • Agree 100%. Search the blog text here with Fung. So pleased to see that several others also have found him!. And I have read the book too. Great read.

        • Hello Sten
          Glad to have your opinion!
          I am also very much a supporter of Dr Fung and enjoyed his book so very much ~ it makes so much sense.
          And having a specialist, who is engaged daily by multiple cases of kidney failure and other conditions caused by diabetes, he has my trust. His experience is direct, long standing and is accompanied by extensive teaching; his ability to see first hand and to access and also compile his own statistics and facts only adds to the unique perspective he has, and serves to validate his medical opinion.
          It is indeed a ‘great read’!

      • Dr Fung does Ketogenic diet, which I have done already, but the keto diet makes me feel horrible and I think it has to do with the low carb because I had severe adrenal failure back in 2014 and am still recovering. I’m not sure that it is safe for someone with adrenal issues to go low carb since it can send us crashing again? Any thoughts? Anyone who had severe adrenal fatigue get better from low carb/keto? When I say I had tried everything, I mean I have tried EVERYTHING!

        • Stephanie

          Dr Fung is a nephrologist.
          He has a website and takes questions.
          Please try to do a search on his blog site~ I did write in one time and he did answer me.
          He also has an assistant as well.

          Give it a try, you have nothing to lose and a whole lot to gain!
          Please keep me posted Stephanie~ I’d love to hear from you.

        • Stephanie~ Not knowing where you are, but perhaps one of these affiliate practitioners would be near to you.

          Otherwise, you can do the distant program they have (for a cost)

          Regardless, please, give the book a try. There is more to it than a ketogenic diet…much more!

        • Eat Stop Eat. Or Intermittent Fasting. Anything that causes you to eat less calories than you burn WILL over time reverse your type 2 diabetes.

          The fastest way is a crash diet of ~600-800 calories comprised of at least 70-80g protein (to help you spare lean muscle mass losses), maybe 5-10g of essential fats, and the rest in complex carbs.


          This forces your body to burn the fat in and around your liver, pancreas, muscles, and other organs that are causing the insulin resistance.

          As this fat is burned up you will see progressively better fasting insulin numbers until you are completely NORMAL.

          Congratulations you just reversed your insulin resistance and type 2 diabetes!!

          Now go as close to whole-foods plant-based vegan as you can while maintaining low amounts of essential fats and you will not only maintain your health, you will increase your longevity — just like the traditional Okinawans.

          • Disagree strongly as it is same as biggest loser and is therefore bound to fail just as they did: Within months the wight is coming back and the diabetes at the same time. Unless you accept to freeze and feel miserabl for the rest of your life. This is the reason banting like this ends fails/ends up in jojobanting. It does not matter. Maybe if you go to extreme and remove all fat it may work. One method is to water fast for up to 5 days or until BG is just over 3, followed by low calorie high fat and low insulin driving meals (keto diet), once a day for instance. The fast empties the liver of gycogen completely so there will be no more “high morning sugars”, and it also sets down the insulin level allowing fat burning from day 1 of the diet. Best induction is to start with the keto diet a week before, as it is 100x easier to fast without cravings than with ! The fasting is the reason GBP operations work in the beginning: The days before and after consists of 5 days fasting and that drops the Blood Glucose and insulin to normal and no insulin required any more ! But also GBP’s fail for the same reason people become diabetic -2: Too much refined carbs in the diet.

        • Stephanie you are correct, keto Genesis is awful for anyone with adrenal failure. A low carb diet causes cortisol to rise and this is awful for anyone with adrenal failure or hypothyroid. The ONLY thing that has worked for me is slow burning carbs like, quinoa, beans, and lots of fiber along with healthy proteins and fats. No sugar . This is the only thing that works. No eating three hours before bedtime and plenty of water. Stay away from low carb diets. Bad news for people like us.

          • Shawna,
            If you refer to the study entitled “Effects of Dietary Composition on Energy Expenditure During Weight-Loss Maintenance”, it was not really a finding that cortisol increased on LCHF. Cortisol reduced in all groups, but least in the low carb group. Hence no increase cortisol from low carb.
            It is also well known that high protein intake increases cortisol.
            Unfortunately protein was not kept constant in all 3 groups, but was highest, 10% absolute higher, in the low carb group. Instead of testing a LCHF diet, the low carb diet was more like an Atkins diet, something that failed years ago, due to too high protein intake, it is widely believed. LCHF stands for lowered carbs, increased fats and unchanged proteins. Still all people do not thrive on the same diet, and although high protein diet in general is implicated for cortisol increase, I have seen no evidence that high fat increases cortisol in general or on average. If you have, please post a study link! Yet we are, thankfully, thriving on different diets.
            Here is one elaboration by Peter Attia.

        • Stephanie,
          You may be interested in reading Dr. Sara Gottfried’s book, “The hormone reset diet”. She is a brilliant women’s health physician and discusses reasons why the keto diet and paleo do not work for some women. It’s all about the delicate balance of hormones. Have you tried taking adaptogen’s for adrenal fatigue? I would recommend Adaptogen by

          • I am way ahead of you. Already tried Sara Gottfried’s book on hormonal reset and it didn’t work for me either (followed it exactly for over 3 months and still eat that way). I also do adaptogens as well and they aren’t working. Gottfried isn’t that brilliant as she is missing a lot of info in her books and references doctors (who I’ve been too) who aren’t that good either. I have other health issues (SIBO, adrenal fatigue) but doctors aren’t listening so I am navigating this road on my own.

  13. I think this article is accurate. Cortisol also raises blood pressure. Whenever my elderly mother wakes up, it has usually been over 12 hours since she has had any food or drink. And her blood pressure is usually rather high, such as 170/95. But as soon as she eats a meal, it drops dramatically, often to something like 115/70. She’s on a very low-carb diet as well. So, I do think cortisol is the culprit. Apparently a drop in blood pressure after a meal is common among the elderly.

    • Could a glass of water on awakening have the same effect in lowering morning blood pressure? I am heading for 70 next month, seeing a few more visits to the loo now than years ago; meaning that we may not recycle water as good as we used to do when we get old. The supreme water recycling example would be the hibernating bear, not drinking or peeing anything for months! Has less water, thicker blood, higher blood pressure any bearing?

      • Great question, Sten. I’ve tested this on my mother. Although I do think water thins blood, I haven’t noticed that big a change in her blood pressure after she drinks some water upon awakening. OTOH, after a meal, the change in her blood pressure is dramatic. I’ll have to test it some more, though.

        • Sam – Could it be that when seh eats her breakfast is the time she takes her meds and its the meds and food combined that has this effect, same with my father.

  14. Hello,
    I think Dr Jason Fung would disagree for at two reasons. First is that IF is probably one of the few ways to cure a metabolic syndrome, the root cause of poor blood sugar regulation. Secondly because he means that the reason for increased blood sugar during fasting is “a liver full of fat and glycogen”. We know that high insulin stores sugar in the liver and prevents the liver from delivering glucose into the blood stream, (and prevents fat burning..). Low insulin does the opposite, and during fasting insulin drops (all relative to ones personal levels), which means that the liver opens up glycogen stores and blood sugar goes high. Same thing every morning.., but less. After a few days fasting, in my own case, (pre-diabetic) my morning blood sugar dropped every day. For a 4 day fast, it started in my case at 5 first morning, then dropped to 4.4, 4.2 and 3.8 over 4 days. (I had done one meal per day for a week before, reason for the good start value I think) Fung has an excellent article about morning sugar. Google Jason fung dawn phenomenon to find it!

    • hi there: Can I ask you how many days could it take to drop sugar readings while fasting? I have done 2 days so far and my fasting sugar levels are 147…however I want to commit fasting at least 5 days for 14 hrs in a row at a time…i expect sugars to start dropping by my next reading (tomorrow) im on a LCHF diet as well, I would appreciate your answer


      • Since you are only fasting 16 hours in row it will take longer than if you water fast for 24 or 48 hours at a time. For each stop it may take up to 8 hours to get back where you were, blood sugar wise. The fasting time it takes to get back normal fasting blood glucose depends hence on how long periods you fast, your initial fasting blood sugar readings which is related to how fatty or even enlarged the liver is starting out, or how much glycogen and fat it stored starting out. But one fast at a time will get all back to normal. Morning blood sugar is the simplest indicator of the liver condition. But if you took alcohol night before, blood sugar is down due to that liver becoming busy cleaning out alcohol instead of making sugar. A false good!

        If you decide to do water fast, please start with only 24 or 48 hours and feel yourself forward. Increase a day at a time, if you need to increase at all. One meal per day over a week is almost twice as efficient than 16/8 or every 2nd day, as the time when no food left is around 16 hours per day then, while only 8 on 16/8 and 16 per 2 days on every 2nd day. With longer fast there is room to eat more when not fasting, which helps metabolism to stay up. Lunch to lunch or dinner to dinner is what I started out with.

        • Stin,
          I tried a fast and was going for 48 hours. I was perfectly fine for the first day. BG levels 70 fasting-max was 92. I even did some weight training and felt great.

          On day 2 BG was 71 and as the day went on I started going hypo lowest reading was 63; so, I broke the fast and added a little bit extra carb than I would eat for a normal meal. My 2 post parandial GB was 84.

          I’m not sure why I went so hypo. I’m still 26lbs over my goal weight–so, I didn’t anticipate my GB levels going into the 60s. That’s just too low….Any thoughts?

          • Sharon, thanks for the comment. If you got dizzy or felt weak, I can only guess, but if you felt fine it is a natural thing. BG drops as ketone production increases and roughly the sum remains the same, I read somewhere about it. I felt even more energized when BG dropped to 3.3 mmol/l day 2 or 3. It makes sense as ketones burn more efficient than BG. If you felt bad with low BG my guess is that you need be better adapted to burn fat. Easiest way is to reduce carbs and increase fats while not fasting. Cheers and Good Luck !

            • Thanks for the feedback Sten. I’ll research more about the information you provided. I felt perfectly fine when BG dipped low, but didn’t want to go much lower than that!

      • I’m in the exact same boat. I’ve been fasting for two days and my blood sugar has gone up to 143. A week ago my fasting blood sugar was in the 80’s or 90’s. I’m now in diabetic range and very nervous about it. Will it self correct?

        • After 3 days water fasting ( zero calories, forget Mosley and others) Mu fasting BG had gone for 6.5 to 3.8. After 2 days it was around 5.
          Don’t worry, when the liver is full with sugar (and fat) it takes some time to empty it. The so called “physiologic insulin resistance” is a brain ghost invented by carb lovers. Eating carbs the night before helps, as it keeps the insulin high so that the liver will never empty excess sugar. A safe route to get or prolong DB-2.

          • Thank you Sten! I tried another fast and the same thing happened my blood sugar keeps going higher and higher The longer I fast. It seems like everyone else’s sugar is coming down. The higher it goes the less it comes back down. I’m not sure how to proceed.

            • Did you really water fast ? Minimum 3 days !
              Maybe your liver is very swelled taking even longer to empty the glycogen in store?
              Unless it is empty during fasting blood sugar will remain high.
              Daily walks/exercise will consume energy and will this speed up the process.

              • Yes I actually did just water. I got my doctor in on the action and he said that he has absolutely no idea why my blood sugar’s are going up with each passing hour of fasting. As far as exercise I usually run for an hour every day. Interestingly enough my blood sugar goes up after exercising as well. I wish someone had seen this phenomenon before and knew what I could do about it. I’m an RN and have asked all the doctors I work with and they’ve been testing me my A1 C is 5.2 but they have no idea what’s happening. They said not to continue to fast because it just keeps going up and up when I do so.

                • Lee, how many days in a row did you fast ?
                  3 – 5 is needed, just 1 or 2 is not enough to “turn the tide” of glycogen flushing out glucose from the liver in the wake of lowered insulin.

                  Many people “turn in the door” when they see BS going the opposite they expect from fasting, but that’s the way it works:
                  It goes up before it starts to go down. And when it reaches 3.5 it is usually perfect as the sum of the BS and ketones then make up your well being.

                • Hi Lees,
                  The most obvious variable that I notice is that you are exercising too much. When you exercise for greater than 15 minutes, your body responds by increasing cortisol. Cortisol is the natural form of Prednisone ( which usually causes weight gain and high blood sugar, as you probably know ) If you are trying to burn fat long term, you should immediately stop running and switch to high intensity interval training (HIIT). I would recommend that you research the Tabata Protocol; in a nutshell, you go full force for 20 seconds, rest for 10 and repeat for 4 minutes. Sounds too easy but check out the data from one of Dr. Tabata’s research articles ( . There is not a one size fits all answer to any medical issue and you may need to do more experimenting. Good luck!

                • Thank you Martha! I think the high-intensity interval training is a great idea. I’ve heard that that’s the best thing for trying to burn through my sugar. My problem is with the fasting if I don’t eat the second I get up and every few hours my blood sugar just keeps going up that’s what we’re working on. Three weeks ago my fasting blood sugars were anywhere from 70 to 90. We are trying to figure out how to get them back down so…. we tried the fasting, (we meaning me and my doctors) They both said that it should go down with the fasting and it just keeps going up. My A1 C is 5.2. I was just wondering if there was anyone else out there that had the same experience. My fasting blood sugar this morning was 125. I was told my insulin is working because after I eat within an hour my blood sugar is back down under 120. However I cannot get it to go much below that. Just looking for answers.

                • As
                  Jason Fung has explained, FBG can keep going up for several days during fasting. It is the lowered insulin that allows the stored glycogen out from the liver. It is a good thing ! I.F. speeds up the process of burning that sugar. After 3 days my BG finally landed around 3.0. Lots of energy then as “the rest” then was ketones. But you must do WATER FAST. No few 100 calories except taste ( of lemon) allowed. GOOD LUCK!

                • Would you mind telling me where Jason Fung says it’s OK for your blood sugars to keep going up with fasting. I’ve looked all over his literature and haven’t seen anything like that. That would actually make me feel much better because the doctors here said to stop until we figure this out. They have many patients that are fasting but none of them are having their blood sugars rise like this. They usually go down. I can’t keep having them go up higher and higher and not come back down.

                • Fung writes about it in the “Dawn phenomena” here:
                  The article explains why it is a good long term solution to allow a short period of blood glucose rise during a fast!
                  Often it instead recommended to suppress dawn phenomena with more carbs in the evening, extra insulin or tablets. But this has instead a long term disease worsening effect as it cures the symptom but leaves the root cause become worse. Once the glycogen is emptied I understand that the liver also starts to metabolize some of its fats and making even more glucose in the process and I am not sure how long this process can go on for a diabetic-2 with a liver maybe twice as large or more than a normal liver. But the size is probably a good clue to the time scale. On the other hand most diabetic-2 going through GBP have according to studies I have read about normalized their insulin sensitivity and are insulin free after about 5 days of compulsory fast accompanying the operation. Before to empty and after to heal. That’s all it takes to cure diabetes-2! The operation is there to keep patients from falling back fast, as they are regarded unable to quit carbs (?) But starting off with a ketogenic diet the initial water fast becomes easy to start as fasting is using the same type of fuel as a ketogenic diet (fat) , but from the body instead of from food. Follows there is no need for a hospital regiment to do the 5 day fasting to normalize insulin sensitivity and blood sugars out of the diabetic range!
                  Added advantage is that it is easy to retain the gains once outside the maze of sugar dominated nutrition and familiar with IF. Ironically people that have done the GBP are now often given better dietary advise, but after the operation…. Please let us know how you get on!

                • Hope to help and sorry in advance for my english. From what I understood long session of endurance training like you probably did are also a big stress forse the body (like fasting) and it can rise your cortisol level a lot, resulting in rising the insuln level

                • Regarding insulin: I do not know about cortisol levels but my fasting insulin went from 8 to 5.3 measured a few weeks after 3 fasting sessions 4-5 days each.
                  Read Jason Fung’s blog for really good information about insulin and fasting!

  15. I’m wondering if anyone can help me with weight loss resistance. I’ve done pretty much every diet including IF, have FBS in the 90’s and lower 100’s. I’ve gained 30 pounds in 3 years without changing my diet or exercise habits. I eat organic, clean, vegetables and protein. I do not eat any refined carbs or processed food. I’ve even tried levothyroxine for a year without any success.

  16. Great information! I am exactly one of the people Chris is mentioning with already on a paleo, low-carb diet, and active individuals having issues with blood sugar regulation. Only recently have I been experiencing episodes of reactive hypoglycemia and after having blood work done, I learned my ab1C was 5.7. I have started testing my BG levels in the morning and post meals where my fasted BG are consistently in the 90-115 range. However, after meals (45min and 90 min readings) they hover from 110-120. If cortisol dysregulation is the culprit for higher fasted BG levels, what steps can I take to lower my fasted BG and maintain healthy levels throughout the day?

    • I am insulin resistant and the only way I could get my numbers under control was no grains at all. I also don’t eat starchy foods. I started intermittent fasting and my blood sugars are now regulated.

      • Caffeine can raise cortisol (in turn raises BG) so cut the caffeine out. I’m working on getting myself to an ideal weight and maintaining it. My logic is fatty liver. You could also have a lot of glycogen in your body.

        • Mike – How are you doing with fatty liver? Thanks for mentioning the caffeine to cortisol to BG connection.
          Ive done IF for 6 months to a year and feel jittery and more anxious in the am/afternoons, probably the caffeine as I do coffee enemas in the mornings.

    • “Great information! I am exactly one of the people Chris is mentioning with already on a paleo, low-carb diet, and active individuals having issues with blood sugar regulation.”

      So, the question remains, “How’s that fad diet working out for you?”

      Listen people, if you are causing more health problems by doing things that purport to “fix” health problems, stop.

    • decrease cortisol secretion by eating regular meals throughout the day. Stop the fasting. It works for some, usually men, but doesn’t work for many. It’s making your glucose levels worse.

      Continue regular exercise, eat mostly whole foods diet.
      Lots of organic non-starchy fruits n veggies. Some fruit, lean protein and some healthy fat, plenty of clean water.

      Most importantly, manage your stress levels well. Use whatever brings your stress levels the best. Music, massage, hot baths, workouts, meditation, yoga- it depends on YOU and how you best respond to stress management techniques.

      Many Blessings,


  17. I have found the articles extremely interesting and I am very much hoping this may help me.

    My scenario is this:

    I am on the paleo diet and have been for 4 months. I take insulin, about 20-40 units a day. I have virtually no carbs most days. I wake with blood sugar at 125-150 or more. My normal wake up is at about 125. The issues are that by 12pm, I will have blood sugars that rise to 170 +, without any food. Added to that, if my blood sugars are at 150 at 7pm, most times it will rise to 165-185 by 1:00am, no carbs or no food at all. I have tried metformin. No changes at 500mg using long acting metformin. I have tried so many things my head spins. I refuse to give up and just take more insulin. This condition is getting more difficult to control. Any help would be immensely appreciated. Thanks….

    • Tim. I am having this same set of symptoms. I think I have identified what it is, but I don’t have a solution. Some people will tell you to eat an evening carb snack. No. That is not the solution. I think this is an adrenal problem. It may not be a “problem” it may be a normal adrenal response to fasting or zero carbohydrates. The adrenals are sending a stress response to the liver, and by gluconeogenesis the liver is keeping your blood sugars up. The solution is to de-stress your adrenals. And good luck with that. One stress could be zero carbohydrates. You could start adding back some essential carbs–like greens, mushrooms and other vegetables. I read that berberine in addition to metformine can help high fasting blood sugars. Good luck!

      • Gloria –

        I think you hit the nail on the head. I have adrenal insufficiency. At night, when my Cortisol would be lowest, my otherwise normal blood glucose levels would soar. I suspect the liver was responding to the stress of low Cortisol by pushing out sugar as a substitute (glycogenation).

        Then I was given Hydrocortisone to supplement for the low Cortisol. Suddenly, my usually normal day sugars and A1C rose, and before you knew it in a year I was diagnosed with T2D.

        Frantic, I weaned myself off the Hydrocortisone, and was started on Metformin. Blood sugar and A1C lowered, but as the blood glucose levels lowered my Cortisol levels plummeted.

        So for people like me, the dilemma is this: Too low Cortisol raises blood glucose levels to compensate for the adrenal insufficiency, and the amount blood glucose is raised depends on the severity of the adrenal fatigue. But paradoxically, too much Cortisol drives blood sugar levels up as well, inevitably leading to insulin resistance and, overtime, T2D.

        Have tried Paleo, Low carb, high fat, and variations of all to no avail, with each leading either to low adrenal function or high sugar release, or both. Also tried Intermittent Fasting, which is a solid approach (Dr. Fung and his group are a great resource), but the Cortisol levels got drastically low and the blood sugar (glycogenation) compensated by soaring again, especially overnight. Hard to believe there could be that much fat/sugar stored in the liver, but I guess it’s possible.

        Anyone have suggestions?

        • Check your fasting insuiln levels. Once below 6 most of your night and morning blood sugar spikes will vanish. To get it down there is only one way. Periodical fasting. It is also made very easy to fast a few days in a row if you first reduce carbs and increase natural fats for a few weeks first. Hunger pangs will go first. Good Luck.

    • There is a new group of doctors out there who say that taking insulin is like giving alcohol to an alcoholic. If you google Prof Tim Noakes and nephrologist Dr Jason Fung, you should be able to find out more.

      • Well you can’t just stop taking it! Even on insulin, my fasting sugars are in the 250’s. When I eat LCHF & IF, I’m lucky if they run 140’s + insulin. I’ve tried adding back a little carb – shot them up even higher – stopped that! I’ve tried eating 12/12 so I have a high fat/moderate protein breakfast in the morning and a Keto dinner. They came down during the day but fasting was still 250’s.
        I laugh when all of you worry about 110 as a “high” blood sugar – I’d kill for that.
        I exercise to muscle failure 3x/week and walk every day, usually a HIIT walk for 30 minutes. NOthing is working and I’ve read Fung’s website and book. I think some of us are just destined to die of metabolic syndrome.

        • Hi Janni,
          One needs to water fast for 3 days to get blood sugars down under 100 when they are as high as yours. In the beginning FBG goes up because the lower insulin from no foods allows more sugar than otherwise to be released from the liver. But starting out on LCHF is a great advantage as it makes the “impossible fasting” so much easier. It takes you past day 2 and after that it is easy. Don’t go more than 3 days first time. And read up Jason Fung’s blog for gradual re-feeding with broth etc.

          • I’ve also read most of Dr. Fung’s info and like Janni would love to have BS in the 100’s…I water fasted for 2 1/2 days and my bs never went below 189, remaining between 219 and 240 for the entire time. I began eating again out of frustration, am I being too impatient? Does something magical happen at day 3? I don’t take any meds as they all disagree with me. I’m Type II from gestational DM 6 years ago…it seems so hopeless. I’m doing keto for the last 4 days and again, 210 is lowest it will go… I do know I need to increase my activity–it was 210 after Taekwondo…I’m adding HIIT tomorrow but would appreciate any specific words of encouragement or understanding of how long I should expect to go before seeing results. Thanks so much and thank you for this forum!

            • Nothing magical happens. But after 5 days GBP patients have normalized blood sugar and insulin levels. They get it only through fasting, that is compulsory before operation to enable it and after to allow to heal.
              You do the same and you are there.
              And yes, BG keeps rising before it drops, because the liver is 1/ usually packed with glycogen and fat 2/ usually a lot larger for diabetics meaning a longer time to empty it.
              Adding HIIT and exercise speeds it up of course as then more of the liver energy is used up instead of raising blood sugar.
              Good Luck Now !

  18. Hi Chris,
    I am 34 and was diagnosed with Type 1 diabetes 18 months ago. Shortly after diagnosis I switched to paleo and low carb and only require occasional insulin if I have a high carb meal or for a few days each month around my period when my fasting blood sugar tends to be higher than usual.

    My problem is that when I take the long acting insulin I feel physically edgy and my body is tense all day long even though my blood sugar levels are normal. This happens even if I take long acting insulin outside of the time of my period.

    I am wondering if this is related to cortisol dysregulation? It does not occur when I take rapid acting insulin such as with a high carb meal and when I’m not taking long acting insulin I feel great!

    For months before and shortly after diagnosis of Type 1 diabetes I had this same constant nervous tension (even before I went paleo/low carb so I haven’t linked it to my diet). No one was able to shed any light on it for me and the only test results that showed anything were that my salivary cortisol levels were very high all day long. I have only recently linked this same feeling to when I take long acting insulin so I believe it is somehow related to autoimmune/diabetes.

    I have had no luck in getting any insight from my endocrinologist so any help would be much appreciated!

    • Vitamins and minerals are very important to make hormones such as insulin , thyroid , etc . Just following a paleo diet many times is not enough , because most diets , even healthy ones are deficient . We need to get adecuate amounts of calcium, magnesium and potassium every day ! Also zinc and selenium are very important. And make sure to get methylated b vitamins , especially if homocysteine levels are elevated. All this helpes to regulate sugar . Some people also have a defective gene and don´t make enough cortisol , which makes it harder for the body to regulate sugar levels.

  19. I’m a 69 years old male, I’m on hormone therapy combating prostate cancer. My fasting glucose level, is between 90 to 97. The side effects of hormone therapy is weight gain and increase belly fat. I also think that it has effected my glucose level, like increased it. I am hoping that IF, can offset some of these side effects. I am vegan, no meat or dairy.

    Will IF help as I hope? I just started the eating plan, yesterday, with a 16hr fast. How long do does it take to see some measureable effects, if there is to be?

    • Dale. What intermittent fasting really does is reset your insulin which may be off from following a high carb junk food diet. You may not be a candidate. It looks like your “problem” is really an effect of the hormone therapy. Is there any way you can work with your doctor to cut back some on the therapy your are doing? And check with your doctor to see if fasting might interfere with the therapy. (Make sure he isn’t just giving you a knee jerk reaction, Oh fasting! That can’t be good!)
      Your fasting blood sugars are ok, probably healthier to be in the 80s, rather than the 90s. As you say they may be running a little high because of the therapy. If you want to try IF you should see results in a few weeks. And results would be slightly lower blood sugar, and less belly fat. You will be burning fat instead of glucose. Also, you want to eat a variety of good fats (oils, nuts, seeds), along with your regular vegan fare.

      • Hello Gloria and all of you IF people, just wanted to give an update on my progress after using the IF method to reverse my type 2 Diabetes, I’m so happy to say that my numbers have changed dramatically. My fasted blood sugars were out of control (over 300) and now since I’ve gotten on the IF diet, my numbers are no more than 120 and sometimes under 100. I have to admit it does take work for your body to adapt but it eventually it will, combining HIIT (high intensity interval training) workouts, along with IF and a fully committed KETO diet, you will be amazed at what you can achieve. I wish that some of my closest family members that have deceased because of Type 2 Diabetes would of known about this, they never stood a chance, I just feel so blessed that I found out how I can fight back and “kick type 2 diabetes ass”. I currently feel “leaner, faster and stronger than ever. I thought I could never stop drinking soda and now I don’t even crave it lol. I can’t wait for my follow check up with my Dr and brag about my numbers because he thought that my diet was extreme and immediately wanted to put me on insulin, Actos and merformin. But I declined I told him let me try my IF method and if this doesn’t work then i guess I’ll have to start heavy meds, so 3 months later “bam” Don’t need those meds, I stayed with metformin but to be honest with you guys, that pill really doesn’t make a difrence so when I go back I’m going to tell my Dr that I want to try 3 months without metformin or any diabetic medication to see my results. Here’s my iF process on mon, wed and thurs I hit the gym at 6am I combine weight training and cardio with HIIT workouts, 9:30 i’ll drink my black coffee and won’t eat until 2pm, then my last meal at 8pm, but before all that you need to consider watching your cortisol levels and also monitoring your sugars 3 times a day, to see what foods really spike up your sugar, but anyway just giving you guys my update and I hope someone here will take the time and read this to be as blessed as I did, to learn this knowledge, thanks guys and good night.

        • Wow! Arod. I am impressed. Shows what can happen when you take reversing diabetes seriously.

          One question: Watching cortisol. How do you do that, and what do you do if your cortisol is running your blood sugars up?

    • Update from my previous post. Two weeks after I started an IF regimen from 6pm to 9am, I check my blood glucose. I was consistently over 90 and my first check this morning I’m at 74. Hopefully, I can contribute this improvement to the new regimen. Its never since I have been checking has it been that low.

      • Yesterday I listened to a presentation between Brian Mowl (diabetes educator) and Dr. Jason Fung. Fung is a proponent of intermittent fasting. I tried intermittent fasting and essentially reversed my Type 2 diabetes. The only remnant is high morning blood sugars. I am inspired by what Dr. Fung said yesterday: Its a back log of sugar. Just keep fasting and eventually you will use it up and your body will be normal once again. Dale, I am envious of your 74 morning blood sugar. And I am going back to my fasting routine to see if I can accomplish the same. Who knew that that curing diabetes could be that simple?

        • Gloria, I am seeing my step brother today. He has type 2 diabetes, his glucose values are over 300. How much of an impact can IF have on a guy like this? When you were type 2, how large were you glucose numbers.

          • Dale. If he has glucose numbers over 300, either he is newly diagnosed and in denial about the seriousness of this disease, or someone has convinced him to manage his diabetes with insulin and he hasn’t a clue about the dietary changes he needs to make. I was on insulin briefly, but I wound up with bg numbers in the 40s, and faced passing out. Finally, the endocrinologist put me on metformin, only.
            i don’t think Ive ever had numbers in the 300s–because I am pretty careful about what I eat. I have pretty much been off sugars, grains, and processed foods, even before I was diagnosed with diabetes. My diagnosis followed a period of severe stress (job harassment). And stress is significant for diabetics and anyone living with a chronic disease. As for your step brother, if he is on insulin, that may be a complication, be cause he is going to have to commit to the necessary diet changes, and then wean off the insulin. Also, people get attached to the bad food they are eating. And no one likes to make changes away from their familiar things. I am sure IF is the way to reverse Type 2 diabetes, but it does require some commitment and determination to get well. Search for some basic articles on EF. I find the “window” method easiest, rather than fasting whole days at a time. Just define the hours you are going to eat, and then don’t eat the rest of the time. Dr. Jason Fung says it doesn’t matter, any mode of fasting will work. But, the foods eaten when you do eat have to be the highest quality- no processed foods, sugars or grains. And, thanks for caring about this guy. I hope he decides to do what it takes to get healthy.

            • Hey Gloria, I spoke with my step-brother about his situation. He is not taking insulin but is on metformin. He is on a low carb diet. He is also kind of on a non-regimented fasting regimen. I believe he has been doing for 1 to 2 months. His fasting glucose is now 370+. If he is truly doing what he says, should he be having better results than this? He has lost about 35lbs, he’s a big guy. I would say hes 240lbs. He is also 76 years old.

              • Dale. I am 75, and one thing Im learning is there is life after 70. I mean 70+ year olds can and do have a right to be healthy! I have also found that fasting seems to trigger high morning glucose levels–for me its in the 160s to 180s even though I haven’t eaten since 4 pm the previous day. Dr. Jason Fung recently spoke about this (Q&A with Brian Mowl). He says its just that we have a large sugar reserve, and the solution is to just keep eating right –off processed foods, eating mostly fruits and vegetables, and fasting, until the reserve is depleted. Metformin is a good strategy–at least according to Life Extension Magazine. It not only keeps insulin levels low and regulates insulin resistance, but it also is antagonistic to cancer. And for diabetics–with all the excess sugar we have–cancer is an ever present danger. I would say he is on the right track. And he is so lucky to have your support.

                • Hi Gloria, I recently started experimenting with intermittent fasting by leaving at least a 12 hour gap between eating dinner and breakfast and sometimes I don’t feel like eating breakfast, so skip that too. I’ve been tracking blood sugar levels as I do this and find that the longer I fast, the higher my fasting BG. I’ve been tracking this for several weeks and my fasting glucose is at an all time high now well over 100. I know this might not seem like a very high level, though it is the trend that worries me. I’m hoping that these rising levels are simply the liver releasing excess stored sugars and that eventually I’ll be able to see the trend reverse? I feel fine when I do IF, though I do have a history of adrenal fatigue and only weaned final doses of oral hydrocortisone 2 months ago. There was no way I could fast in any capacity while I was taking HC. Since weaning, It has felt so liberating being able to go so many hours without eating. I just question the efficacy in light of Chris’ article above.

            • Anita. How long it takes, depends on how you do it. Frankly once I started intermittent fasting, I felt so much better I never want to go back. I have been following it now for about 2 years. If you fast one day a week, you will not do as well as fasting 8 to 12 hours every day. Also, Dr. Mercola is now recommending to eat just 2 meals a day rather than 3 or more within the fasting framework. I would agree with that if you have metabolic problems like diabetes. Since eating a meal is problematic–why do it more often? I would say you should see better blood sugar readings after about 6 weeks. But fasting has many other advantages besides better glucose control–it is now being recommended as a longevity strategy.

            • Anita, its been 6wks with IF. My fasting morning glucose numbers have been fluctuating. I reported early on that I got down to 74 but subsequent numbers have been 83, 96 and 93. I think to reduce my numbers I would need to change my diet, more. I eat a fair amount of fruit during the day. I am not going to do anything until I can get out of the effects of hormone therapy. My testosterone is 0, which in itself can effect blood chemistry. So, I will see where I stand in a few more months. I plan to stay with IF during the wait. Good luck

              • Dale. Those numbers for fasting glucose look great to me–but then I am a diabetic. Im still trying to get mine under 100. However, your A1c score is probably a better indicator of how you are doing. Mine is 5.5, after intermittent fasting about 2 years. keep up the good work.

    • Hello, I have started with IF ( twice per week for 24 hours ) in order to loose weight. I combined it with 4-5 days per week of weight lifting and steady state cardio ( below 75% of Max ) . To my surprise not much happened. I started paleo diet ( 4 weeks ) and still not much happened. Then a friend suggested I extend the IF to 36 hours from 24 hours. To my pleasent surprise I started loosing about 2 lbs a week . So far lost 30 lbs and 7% body fat ( which slightly concerns me because it implies I also lost muscle ). Recently I decided to increase my protein intake to about 1 gram per pound of body weight and started taking BCAA before my fasted workouts. Hope that helps

    • Lins, I would start by simply reducing (half ?) the long acting insulin on my own to see if any effects.
      There are different hormone therapies. Make sure your doc is not giving your “hormone replacement therapy”, patented synthetic hormones, but instead bio-identical hormones. The latter are natural, lower cost, not patented. GABA can help jitters in an hour or so. I take a teaspoon of resistant starch in some lukewarm water and unrefined gray sea salt also when I fast as it has no effect on blood sugars but I believe it is great prebiotics.

  20. I’ve always wondered about this topic.
    I’ve tried IF in the past and maintained it for a long time. I was mainly doing the bullet proof diet which consists of high fat and protein diet, very low carbs. First I lost some weight then I stalled. During that whole IF daily, I was ready to faint. Right now I weigh about 125lb and it fluctuates. My last meal was last night 7pm and today I haven’t eaten since 5. Usually if was doing the IF correctly I would start eating at around 3:30. But around 12pm I was ready to faint. So generally if I don’t eat anything for breakfast I get tired, dizzy, spinning head. I’m prone to low blood sugar. But if I have let’s say a normal ice cream I kinda get little excited lol.
    Any advice would be appreciated.
    Oh my current diet is fair amount of carb, (I train Brazilian jiu-jitsu almost 5 days a week twice a day) and grass fed fat.
    Thank you!

    • Kads. I would suggest looking at A. Christianson’s Adrenal Reset Diet and then incorporate those principles into IF – eating within a restricted window each day. When you go with out eating you bring cortisol into play. You can’t eat ice cream (not normal) on an IF diet. it is essential to eat very high quality food, because you are trying to reset your system here. If you trigger insulin, you are going to get low blood sugar. And. As Christianson suggests, you may need to eat more carbs (good quality) with fiber at the last meal. Good luck. Sounds like you need to make a few adjustments to make it work for you.

  21. Thanks for all the amazing info. Hope I am not missing something with this question…

    My fasting glucose is 85. (is this a normal, high or low number?)

    2 hours after I eat my BG goes to 110+ and I get incredibly tired and foggy headed. The only way to remove the symptoms is to take a 20 minute nap. (is 110 a normal, high or low number?)

    My #1 goal is to stop these spikes and fatigue episodes.

    I never eat breakfast, just bulletproof coffee, then eat a paleo lunch and dinner (high protein and fat, low carb).

    I drink alcohol often…

    Carb cravings every day at 3PM.

    Would you describe my condition as insulin resistance, reactive hypoglycemia or a cortisol problem?

    I am generally happy but don’t get enough sleep. Stress levels are fine.

    Thanks for any info.

    • Jesse. Fasting glucose of 85 is a good number, and a post prandial (after meal) blood glucose of 110 is also a good number.
      As for the fatigue you might want to check out Alan Christainson’s Adrenal Reset Diet. he recommends a high protein breakfast (can be a shake), a green leafy lunch with protein, and a relatively high carbohydrate dinner (no junk) for optimum adrenal function and energy. He also has information on resetting circadian rhythms. That should fix your fatigue and energy issues. Lean about healthy carbs–fruits and vegetables and incorporate them into your diet. Alcohol–I would cut back and aim for one or less per day, Alcohol can really mess up your energy, not to mention mess with your liver and your head! Aim for 7 to 8 hours continuous sleep. Sleeping is for regeneration and repair. It should be high priority.

    • Jesse,

      Those are great numbers and don’t suggest any blood sugar issues. If you’re concerned, try eating a highly carby meal of around 50-60 carbs from starches and fruit. Test your blood sugar at 1, 2, and 3 hours. If your readings are no higher than 130 at 1 hour and then begin to drop back down, you’re likely just fine and don’t need to worry about your blood sugar. The fatigue might be from some adrenal issues (as Gloria already said) and I second her opinion about alcohol. A nightly glass of wine or whatever might be completely fine for you, but I would be cautious about anything more than that – and I would certainly take out all alcohol for at least 30 days and see if that helps.

  22. Hello I want some advice, I’m a thin type 2 diabetic (5’4 134 lbs) , very new to the “Keto” diet, I’ve been on it for 3 weeks and emedietely saw my glucose go down, used to be in the 300’s high sugar levels, now currently down to the 140’s max, but anyway is intermittent fasting recommended for type 2 diabetics, I workout 3 times a week in the mornings on an empty stomach since 8pm the day before, I workout for hr and a half ( weight resistance and running intervals) I feel great so far and I know I still have work to do, eventually my goal is to have fasted sugar readings under 100, but anyway another question, when I workout my sugar levels tend to go up, by being on a low carb diet, will my body eventually switch and start lowering my sugars? And if so for how long and if not is there anything I can do to stop this from happening?

    • Arod. Question # 1. Intermittent fasting is recommended for Type 2 diabetes. It should reverse the disease. Keep in mind that your fasting blood sugars do not only reflect the carbs you are eating, it also calls into play gluconeogenesis wherein morning blood sugars are elevated due to the action of cortisol causing the liver to make glucose out of proteins and fats. Intensive exercise will raise blood sugar also, and this also involves pathways other than carb restriction. I don’t really understand your second question. On a non-ketogenic diet, your sugar levels go up, but on a low carb diet will your body starts lowering blood sugar levels and how can you prevent this?

      I understand the goal of ketogenic diet is to train into fat burning as opposed to carb burning as a source of energy. Since you are already lean, you may want to modify the ketogenic diet so it works better for you, since you don’t have that much fat to burn. Iintermittent fasting is good for “resetting” and unbalanced immune or hormone system. Above all, eat high quality food and space it such that during the time you are eating, you have enough fiber, carbohydrate, and protein in your last meal so that you are not triggering high cortisol levels during your fasting period. The point of fasting is not to starve, its just supposed to reset mechanism that have gone haywire for some reason–usually bad food.

      • Thank you Gloria I will definitely take your advice in regards to my Keto diet. I’m sorry about my 2nd question, but you pretty much answered it. But you know what was weird is that I felt I knew more about my type 2 disease than my Dr. He was telling me that the only way to lower my blood glucose would be by medication and maybe in the future get some insulin. When he said that I knew he didn’t understand my disease like me… From what I know is that too much insulin would make things worst, but anyway we did some blood test today and i don’t expect good numbers since I just barely started my Keto diet 3 weeks ago but I will be seeing him back in 3months. So far I only take metformin 1k ml 2 times a day (1 morning and 1 night) and 1 baby aspirin. I hope that with my momentum I will prove my Dr. Wrong and will soon not need medication to lower my gluccose levels, I have started eating big meals on my eating window low carbs high protein, another thing, my Dr. did mention that I shouldn’t worry about eating too much protein, that if anything I should make that a priority since my diabetes triggers my body and supposedly that’s why I’m a thin type 2. He said my body needs more insulin, but I say I just need to be more insulin resistant, I was just so disappointed how quick my Dr. was add more medication vs letting me try to fight this naturally but anyway thank you once again, I truly appreciated and I will keep an eye on that cortisol as well, I feel awesome so far, thank god I haven’t had any complications yet.

        • Hi Arod. Im amazed that you are diagnosed with diabetes 2 at all since you are lean-5.4 134 lbs and working out. Unless you were eating really bad food, there must be something else going on to get your blood sugar up into the 300s. I think you will see results soon if you adapt to a plan of intermittent fasting. Unless you have other reasons for going ketogenic, I would even out to a more balanced diet — leafy greens in the carb category at least. Most nutrients are in vegetables and fruits so if you don’t eat any, you can set yourself up for some nutrient deficiencies. Ive found when doctors start loading you up with drugs its time to move on. And when they start suggesting surgeries you don’t need-run!

          Don’t know what the baby aspirin is for. It may do more damage than good. And insulin for a type 2 diabetic is like prescribing alcohol to an alcoholic. Its the last thing you need. Insulin use can lead to “double diabetes” you lose your a bility to make insulin and become both Type ! and Type 2 at the same time. Note. I am not an M.D. I am an anthropologist and I do have diabetes (or did have before intermittent fasting). So for what its worth … here’s hoping next time you will be report to us on your good health!!

          • Thanks Gloria and I will definitely keep you guys posted on how I will overcome this disease. But as far as how I caught this was hereditary (Dr. Explained) because both of my parents are diabetic and eating a lot of fast food must have triggered something in me.

            • Arod. Recent studies in epigenetics show that genes (as in Type 2 diabeltes) allow but do not determine a disease pathology, so saying that you have Type 2 diabetes because of your genes is a cop-out. its not like blue eyes. The reason you have diabetes (Type 2) is from your own behavior and environmental pressures. And you can recover from the disease by learning to eat nutritious foods (instead of nutrient depleted and toxic foods), and getting a moderate amount of exercise. There is probably a psychological component in there also. A lot of it is just learning to respect your own biology. Good luck.

              • Sometimes things ARE genetic and while we can make modifications to optimize our health, telling an active, lean individual that they’ve done something to cause their diabetes is very unhelpful. Despite a very careful diet, I have blood sugar issues that have amplified during my pregnancy. My doctor isn’t concerned because I “passed” my OGTT, but just barely. Once I started monitoring myself with my glucometer, I learned that my fasting glucose is always between 90-95 (it should be in the 70s while pregnant) and very low carb meals still bring me up to 120ish for hours – even after 3-4 hours sometimes. I reduced my carb intake from 100 grams per day to 50-60 grams per day and took out all starches. I keep 1 serving of berries a day just to stay sane. If I eat anything carby (yes, I mean the good ones), my blood sugar spikes into the 140 range and stays there for a while before making me feel sick and shaky. I didn’t cause this by eating too many bananas and sweet potatoes. It’s more likely connected to a) my reaction to pregnancy; and b) my mother’s daily tray of butter tarts when she was pregnant with me (resulting in insulin resistance from day 1). I also have issues with high cortisol which I am sure contributes and which I am working on.

                • I agree with Sarah, especially about the alcohol. I think the major problem here is that we are worried about blood glucose, when the real problem is insulin–too much of it. But we have no way to measure it.

  23. Hi, I am a 44 yo female dx’ed with late onset congenital adrenal hyperplasia in Sept of 2009, I have done search after search and haven’t found any information telling me if I should or should not be doing IF.
    My adrenals do not make much cortisol, it all goes to androgens which is why I have had a higher testosterone level all of my life. I was on prednisone for a few years but decided to wean off of it because I was not seeing any benefit of being on it.
    I have been doing IF for almost a year now. I was seeing great results at first but I am back up about 5-10 lbs over my maintenance weight. I am 5’5″ and right now weigh about 125 which is ok with me I just don’t want it to get any higher. I also have hashmoto’s thyroiditis.
    So my question is should I NOT be doing IF with this condition? Or can you point me in the right direction to do more research?
    Thanks so much.

    • I have the same diagnosis, but no thyroid issues. In paleo code he does not suggest doing IF for thyroid issues. Do you trend toward low blood sugar or symptoms of low blood sugar? For then you would want to eat every 2-3 hours. The only supplements that worked for me was Chinese medicine….i did all the adaptogenic herbs and stuff for cortisol there was…but that did not work for me, and many made me feel worse.

  24. I’ve been doing IF for about 2 years and started on a ketogenic diet in Jan 2015. I have noticed my FBG to be in the 85-100 range in the a.m. But my Hba1c just tested at 4.5 so I have a hard time seeing that I’m insulin resistant.

    I’m no expert, but I’m not so alarmed given these facts, especially given that my BG will continue to drop throughout the morning until I break my fast. I see something in the range of mid 50s to high 60s by that point, depending on when I eat.

    this lays out an argument that this higher, early morning FBG is a natural adaptation when one gets adept at metabolizing fat:

    It’s intuitive to me that my body has adapted to a low-carb, fat burning state where I might fast 16-20 hours and even do an intense workout in the middle by scrounging up or sparing glucose. I don’t see how this is “insulin resistance” when overall there’s never that much glucose floating around in my blood stream (HbA1c test shows that). It more like my body has a plan B now that it has the option to burn fat or use glucose.

    There’s the cortisol angle, I suppose, which might mean that I’m unduly stressing my body, so it’s something I intend to watch. I’m probably going to play with adding some more carbs in a dinner more consistently to see what that does to FBG….

    • Tony. I like the idea of high FBG driven by cortisol as Plan B.
      I am type 2 diabetic and my A1c’s so far during intermittent fasting were 5.4 and more recently 5.7, at the same time my FBG hs gone haywire 170 or 180 on some mornings. The IF plan Im using to the daily window routine — I eat between 10 and 4 pm. This was a problem and this is when the high FBG occurred. So now Im shifting to finish eating later in the day and fasting later in the morning. I don’t have the results yet. I am hyperthyroid. I don’t see a good reason not to use a mild form of IF with hyperthyroid. i am losing some weight, but it is not excessive. And I am determined to reverse my diabetes. Somehow I think if I get rid of the diabetes, I will also get rid of the hyperthyroid issue. I never have low blood glucose on my monitor, but I still get a radical cortisol surge with gluconeogenesis, running morning fasting blood sugars sky high.

      • I have always had high morning blood sugars, whether my A1C was low or not. I find that eating something around 10 at night lowers the morning BS a great deal: normally 150 or above – this morning it was 110. The numbers have really come down with the keto diet. I starter IF last week so I hope to see a big improvement in the BS levels.

        • Susan. I think you will see amazing results with intermittent fasting. The problems you may encounter are high fasting blood sugars due to morning cortisol. Hunger isn’t a problem after a few days. While some people recommend eating frequently –every 2 or 3 hours to control blood sugar–I think this is mainly if you tend to hypoglycemia. For me that just shoots my blood sugar up into the 300 range where I dont want to be and do not feel well. I think the key to high morning blood sugar is to eat a relatively high carbohydrate meal for your last meal of the day, and include lots of fiber with it. Maybe even a fiber supplement such as inulin or glucomanan. A good guide to controlling blood sugars set off by cortisol is Christianson’s Adrenal Reset Diet. Incorporating circadian rhythms with intermittent fasting I think is the answer. I dont think eating frequent meals is a good idea for someone whose glucose control is problematical–based on my own experience.

          • Yes, eating something with a little carbs works best for me for my last meal. The night before last I ate a small nectarine (1/2 of my carbs for the day!) at the end of my window. Yesterday morning, the numbers were 88. The key is to not eat too many carbs or the numbers are higher in the morning!

  25. Thank you so much for this posting. I know that I have blood sugar regulation problems and have not known how to resolve them. I appreciate the advice to eat every 2-3 hours- makes sense to me, as I feel like I could eat all day long. The challenge is to figure out how to do this on such a restrictive diet. I am following the Autoimmune Paleo diet, the Candida diet, and also a low-oxalate diet. Based on these restrictions, there are only about 15 foods I can eat. I also have to be careful to rotate my foods because of food sensitivities. Does anyone have ideas how to eat frequently on such a restrictive diet? Recommendations for a nutritionist? I would be grateful for any suggestions. Thank you.

    • I would advise everyone to get on a low carb, high fat and protein diet. And than after a few moths, begin intermittent fasting. You will find doing both will be tremendous.

      Eat your fruits and vegetables and keep your carbs between 50-100. You will melt away fat and health problems. You will be amazed. EAT WHOLE FOODS. This is a perfect fit for everyone. Try it.

      You see, fasting gives your body a rest period, and releases all kinds of wonderful hormones, fat burning, muscle building hormones that will burn fat in your body. Doing both will keep insulin levels very low.

      • That is good advise however doesn’t always work. I have sluggish adrenals and liver detoxification and if ..even after ketogenic for years causes my blood sugar to sky rocket.

      • Sal: I guess you didn’t read this article. Chris Kresser says fasting can cause cortisol levels to increase and affect your blood glucose. Funny, I guess you missed that Chris recommends not to do fasting if you have blood glucose regulation problems and to eat every 2-3 hours.

        • But IF has been shown to improve insulin sensitivity.. so if you keep eating ever 2 to 3 hours you are not teaching your body to deal with the problem.

          • I guess it is true to teach your body about dealing with fasting but everyone is unique. First of all we don’t live in the same world as our ancestors so I believe you have to stay on top of what you eat and the chemicals around you. Fasting today is different than our ancestor since anything affects cortisol levels. I’m finding personally cortisol is a problem with my own health problems. I believe stress is a big a factor in our modern lives.

            • I sense the problem might have to do with different genetic problems associated with the pathways involved in processing glucose. The glitches may be at different points for different people, with various hormones as potentially flawed. One of the places this is being studied is the Salk Institute. So different genes for different people that control these hormones may be implicated.

              I myself am overweight and I get some activity, although in the recent winter, not nearly as much. My A1c went from 6 to 8 in this period and I have been prescribed Metformin.

              Meanwhile, I know that in the past I did well with intermittent fasting. I believe that my weight gain made me not so much unstable in blood sugar readings, as predictably lousy.

              For now, my solution will be to make sure each meal is calorically less because even if I think I am getting enough activity (say 2 miles of walking per day on average), this is not adequate to deal with the problem until there is significant weight loss. Twenty pounds off, if carefully maintained (not like the last time I did this), will help. Also, probably some vitamin supplements. I know that my family has a lot of type 2 – my grandfather, mother and half my siblings. The grandfather lived to be much older than the average in his day (83) and my mother is alive at 91 (though blind – which is soooo scary for me – it happened in a cascade when she was about 87, perhaps partly to do with a shock to her system with cataract surgery – don’t really know). We may have some “thrifty genes” which allowed ancestors to get through long periods of near-starvation. But like sickle cell anemia being protective against malaria, this kind of diabetes may have saved lives which later were shortened when food was more freely available. However in our having Type 2, my family is not so unusual for Americans since it is rising here.

              Here I am at my laptop, and the level of sitting during a New England winter is far too much to be healthy in any case. There have to be some guidelines – like getting up for several minutes of any hour for all chair-workers. One burst of exercise in the day, as we know, does not help enough.

          • I have IF’d for 3 years – skipping breakfast, fasting 16 hours a day. Every year my cholesterol gets better, and my blood sugar worse. Over 3 years it’s gone from 99 – 107 – 124. I’m going to give breakfast a shot, and maybe even eating every 2-3 hours.

      • Absolutely disagree. I have been on a strict ketogenic diet for over 100 days. My blood sugar would not come down. Then I tried intermittent fasting and the same results. There are those who do not gain control of their sugar levels. This is not a theory but my own experience, regardless how much sense it makes – IF. My blood pressure increased and my sugars would not drop. I appreciate the article because it makes sense. IF is not for everyone. I am one of those.

  26. I have a feeling that one of the answers to the increase in blood sugar might lie in Stephen Gordon’s post further up the page.

    We are broadly applying the thinking that ‘paleo’ or ‘IF’ etc diets may be helpful because they are more in line with the nutritional environment that we evolved for. It would then make sense to modify other aspects of our life in the same manner.

    Perhaps the increased blood sugar that results from these diets is actually a natural healthy response if we look at the big picture. Maybe our body is moving back towards its natural apex physiology which suits a much higher/intense activity level (hunting, gathering, fighting predators etc) than we are exposed to in modern sedentary society?

    I think Boyd-Eaton(?) had some papers on the activity levels of indigenous/paleo peoples compared to today’s society. Showing that the old “30 minutes of moderate exercise 5 days a week” was nowhere near the levels of activity required to trigger healthy cell function.

    In fact the 30 minutes thing has only ever been the bare minimum required to avoid a diagnosed sickness – which is actually a totally different goal to creating health.

    I wonder how many of the people here have introduced a lifestyle change to a fairly high/intense activity level such as Stephen Gordon’s boxing training etc alongside the IF nutritional changes?

    Also, what about the mental-emotional component of our lifestyle. If this is not also changed in a manner that honours health it can easily contribute to amplified/misplaced endocrine responses. This could also make an otherwise healthy diet appear to be unsuitable?

    Everything is connected – the way we eat, the way we move and the way we think are all interrelated when it comes to non-linear endocrine and neurological feedback loops. Helping the body make its way from high allostatic load back to homeostasis requires an orchestration application of lifestyle change.

    Hence, I wonder if it is not so much a failing of the IF diet, but an erroneous expectation that a nutritional change alone is a fix-all solution a highly complex problem… Seeking to make food a natural ‘medicine’ to fix a diagnosis, rather than seeing it as an integral aspect of a living environment which facilitates for the creation of health.

    Without requisite changes to the interdependent physical and mental-emotional aspects of life we may be compromising or confounding the IF/paleo diets elgance or effectiveness.


  27. Yes doctor, you’ve got the answer why my blood glucose is much more higher at the end of the day than when I get up during fasting.

    I’m so confused whether to take my medicine or eat my low-carb diet or what? Now I’ve got it to to eat every 2-3 hours but moderate amount of food.

    Is there some way to control or reduce cortisol during fasting?

  28. TL;DR: I’m an archaeologist. The paleo-diet is not “one size fits all.”

    I’m an archaeologist who specializes in the studies of diets of hunter-gatherers. I’d say eating every few hours is actually pretty normal. Hunter-gatherers spend a large amount of time foraging, during this time they’re snacking more or less constantly. Like, if you go out picking berries, you’re not going to snack on a few? Also, hunters would usually take food with them.

    What we have to remember is that the hunter-gatherers you see today are disadvantaged, fourth-world peoples who have been forced into marginal environments. Many of our ancestors lived in much more accommodating environments.

    Furthermore, hunter-gatherers live (and lived) in wildly variable conditions, with wildly varying diets. The Inuit eat 90% meat whereas the San eat 90% plants (give or take). If your body tells you to eat every few hours, then do it. It might have something to do with hundreds of thousands of years of your ancestry.

    • Hi Laura. I am an archaeologist, also, and thanks for setting the record straight. Our ancestors normally had plenty to eat. They did not normally spend a lot of time starving. If they did, they would not be us!

  29. Hey thanks for the post. It was very helpful.

    Over the past 3years, I have lost about 30lbs by just eating meat and vegetables with regular exercise. I am a 5’8″ male and weigh about 210lbs.

    I believe I hit a plateau. I am looking into intermittent fasting. I want to start very slow. I find that I have more bowel movement when I fast, once/week. I came to use fasting since I found that after about two weeks of intense/cardio exercise (5x/wk) and eating 3x/day, I was tired and my weight fluctuated between 205-210lbs.

    What are your thoughts?

    thanks so much again !

  30. I just switched over to a 30 day paleo meal plan from “Practically Paleo” from a typical diet high in carbs and sugars. I have PCOS and to help prevent insulin resistance I am on metformin 500mg twice a day. My question is this: I am 4 days in and seeing spikes in my blood glucose levels. I monitor with a meter as you suggested in one of your articles. I typically have very normal non-diabetic numbers for blood glucose. Now I am seeing my baseline at 93-95 and my fasting at 100. Is this typical? should I see it level out and return to my old levels if I just stick with the paleo diet?

    • . getting too much protein can work against the metformin
      by raising glucagon that increases liver-made sugar;
      remember, the magic of the Atkins diet
      in the way it lowers blood sugar and cholesterol
      is not just from being low in carbs,
      but also by being high in fat
      rather than high in protein .
      . try getting less than 50g protein per day;
      and get more gentle, low-glycemic carbs
      like greens, cabbage, broccoli … .
      — peas are a low-toxicity, nearly-Paleo legume
      and hence a good carb according to the Perfect Health Diet .

  31. I have been intermittent fasting for several years now. I stop eating at 4 pm and start again around 9 or 10. I would not eat every 2 or 3 hours — that would only run my bood sugar up. For me eating is a problem, I feel much better when I dont eat. I eat 2 or 3 small meals a day. More ketogenic than paleo. I am diabetic and hyperthyroid. I am now off insulin. A1c 5.4. So Im still working on diabetes. This summer I started having unreasonable fasting glucose readings–to 180. It turned out to be due to deydration — and a faulty blood glucose monitor. I can recommend IF as a means to deal with diabetes.

    • Hi Gloria,
      Thanks for your post. Can you clarify your IF for me? You stated that you stop eating at 4pm and you start eating at 9-10. I assume that is 9-10 AM but don’t want to assume….

      I have been doing IF from 8p-about Noon…. having my first meal at lunchtime. The morning I am drinking some bulletproof coffee. Gets me through the morning fast…

      Trying to get my morning BS’s below high 90’s. Some days it is and others it isn’t. Having quite figured out the trick yet….
      I’ll just keep on working at it.

      • hyperthryoid. No. In fact its worse. Yesterday, the M.D. recommended radiation therapy to destroy my thyroid gland. Also, high morning blood sugars continue. I like intermittent fasting. To me its simple to do, and it does keep my insulin levels low–so A1.c 5.4 tells me there is something right about the method of IF I am using. I don’t want to eat every 2 to 3 hours. It seems to me this discussion is focusing on blood sugar, when the real problem in diabetes is insulin.

    • Well this is June, 2015. The high fasting blood glucose problem continues. I replaced the monitor, and I am trying to drink more water. My fasting blood sugar is sometimes as high as 180. Clearly there are endocrine complications. In addition to the not controlled diabetes, hyperthyroidism has kicked in. I didn’t need to lose weight, but I did lose 20 lbs –and atrophied muscles are starting to show. Also bulgy thyroid eyes. You would not want to meet me on a dark street at night! Houston. There is a problem! Yes I do have chronic stress, from the apartment complex next door–a blaring stereo 24 hours a day.

  32. Sigh! I eat a low-carb, ‘clean, wholefood’ type of diet (spend quite a bit of time in nutritional ketosis), and I fast daily for about 18 hours, plus a 24 hour fast weekly.

    I LOVE fasting – it gives me a sense of control, and wonderfully level energy, and for the first time in my life, I am free of cravings.

    But my blood glucose sux – fasting can be as high as 7, and I spent most of the day at around 6. It drops to 4-5 soon after eating (the strange patterns you mentioned). HBA1c has gone 34mmol/mol -> 35 -> 37 over the last year (which my Dr says it completely normal, as is my BG).

    I am very frustrated – I desperately don’t want to stop fasting and go back to feeling out of control, hungry, and like I am on an energy rollercoaster.

      • Except I’m pretty sure I am not high protein – I am a pescetarian, but my diet is largely planted-based. I worked out I am eating about 50g/day protein.

        I had a look at Zone, and why it may cause high BG – but if it was a cortisol issue then I think I would be experiencing loss or muscle mass, possible weight gain etc, but I’m 14% body fat, and pretty strong, so I’m not convinced it is that. Interesting trying to work it out.

        • I wasn’t referring to your cortisol;
          the zone diet says dietary protein raises your glucogon hormone levels
          which cause your liver to produce more glucose;
          you don’t need 50grams per day unless you’re doing major weightlifting work .

          • PhT. – I believe that this is what occurs with me. If I eat more protein than 50, my morning FBS seems to be elevated (high 90’s to low 100’s). If I eat limted protein the day before, I have been getting FBS’s in the 80’s. I am finally getting to the bottom of this. I think I am very sensitive to carbs and protein. Too much protein is not what is needed for me.

    • Fasting and consuming high fat only gets very old. If I fasted as much as you did, I would be ripped to shreds.

      You never want to totally get rid of wholesome foods, like vegetables and fruits. I understand fruits have sugar, but eat small amounts.

      I seldom use ketosis. I like staying between 50-100 carbs per day.

      I like ketosis in theory but giving up my fruits, can’t do it. Wholesome nutritional foods have too many benefits for the human body.

      Ketosis is overrated. 100 grams and below should do you well. You need some carbs to keep your body to trigger bother energy sources fat and glycogen. Have the best for both worlds just do not blow out you cabs consumption. Works for me.

    • I agree. And I think the problem is that we are using blood sugar levels to guage how our diabetes is doing–when we should have some way to measure insulin.

  33. Cortisol is a hormone that’s released when we are physically or mentally under stress (the body can not tell the difference between the two) the reason that blood sugar increases is because your body thinks you are about to be physically active. So it provides glucose for your muscles… Even if you aren’t going to use them

  34. I find this very interesting. I believe that I am similar. If I don’t eat for a long period of time, my fasting BS is high 90’s to 110…. When I eat prior to going to bed, my fasting BS is better. I think I am going to have to do some more reading on this to get a better handle on this. I had no idea. Thanks everyone for sharing your stories.

  35. Thanks for these fabulous posts! It is refreshing to hear some data from a practitioner who is NOT just pushing pharmaceutical solutions. I am attempting to lose weight low-carb style. I know I’ve been insulin resistant for years. After a week and a half averaging 14g of net carbs per day, I’m only losing a small amount of weight, and my blood sugar is hovering between 95-100 (fasting and after meals). Why would blood sugar remain so high, and why am I not seeming to stay in ketosis with heavy carb restriction? Thanks!

    • I’m anxious to hear some responses as I am in the same boat as you. I don’t think I am as low as 14 for carbs each day…. that’s pretty incredible.

    • . if 14g of carb hinder ketosis,
      consider less-glycemic carbs, eg, for 2 weeks
      try your only carbs are a soluble fiber supplement
      and remove conditions causing insulin resistance
      like caffeine, alchohol, other meds .
      if stress or lack of sleep is causing
      too much cortisol and not enough DHEA,
      do weightlifting or peak resistance isotonic exercises .

    • moderately educated theory here:

      protein, especially in excess(high) amounts as in many low carb diets can undergo the gluconeogenesis pathway. If you were eating a traditional/standard american high carb and relatively frequent meal schedule prior to switching to low carb but high protein, perhaps the body is trying to do what it’s used to – using the enzymatic pathways that are ramped up – burn glucose for fuel. To get the body shifted to fat burning, we have to eat fat and moderate/adequate protein (approx under 100 g perday) and fasting should help with that, but it takes some time for the body to build up the fat/ketone burning enzymes. Apparently, I believe I heard in an interview with Tim Noakes, full ketoadaptation can take years.

  36. Hi Chris:
    This sounds like me! I’ve had reactive hypoglycemia for years. Now I’m dealing with post-menopause while on bio-identical hormones. Meanwhile, my fasting blood sugar is hovering around 100, my cholesterol is over 200 even on a statin & I just feel old & gross. I’m 51 & weigh 170. Yuck! I know eating my husband’s BLT, tuna melt or chicken parm w/ garlic bread along w/ several glasses of red wine on a Saturday night aren’t helping! I know I need to exercise but I feel so wiped out after work & a 40 minute drive. I also have a spouse & an 11 year old (which is great) but does take some time. Sorry this is so whiny but it’s been hard to find sound realistic diet & exercise advice for women my age! I’m having a hard time with sustained motivation! Thanks!

    • I think it is very difficult to focus on personal habits and needs, when your life is focused on others. Getting healthy is about personal responsability –and that is not an easy thing to do when your life is oriented to responsability for others.

    • Having cholesterol over 200 is not a bad thing , as long as the HDL / LDL ratio is right . We need cholesterol to make vitamin D and many hormones , as long as we are consuming healthy fats ( butter and eggs included ) thats fine. A great book to read on the subject is ” The Great Cholesterol Myth “.

  37. hey everyone- i have a question. can anyone tell me why i get horrible hypoglycemia, weight gain, and just feel horrible when my cortisol is LOW? i have had cushings disease, and when my cortisol is high i immediately lose weight, feel wonderful, and my blood sugars normalize. this is the opposite of what should be happening. any advice is greatly appreciated. i recently had to have my adrenals removed because of the high cortisol- and the cure from cushings and the “low cortisol” has brought on serious weight gain, blood sugar issues, and pre diabetes. it is insane. any a dice is greatly appreciated.!

    • if you felt great, why remove your adrenals? just kidding 😉
      too much cortisol is like too many pain killers …
      you feel great but you die young .
      . usually people who feel bad (as from low cortisol)
      abuse food — which would be the likely cause of your
      “serious weight gain, blood sugar issues, and pre diabetes.”
      . it’s not high cortisol that causes blood sugar instability;
      rather, insulin rebound from a glycemic (grainy sugary) diet
      (which mean having too high then too low of blood sugar)
      causes cortisol to be raised in order to
      protect the brain from low blood sugar
      (cortisol causes insulin resistance in the body
      so there is a guaranteed supply of sugar for the brain).

    • From what I’ve learnt on my MSc in personalised Nutrition, when your blood sugar levels are low, your body needs to pump cortisol & adrenaline from your adrenals to raise your blood sugar levels, so if you can’t produce enough cortisol to do this, your BS will remain low. It also uses glucagon from your liver to turn glycogen into glucose but if glycogen is depleted through low carb diet then you won’t be able to increase your blood sugar that way either…just a thought

  38. I didn’t hear any mention of time frame. Yes, glucose may temporarily be worse, but is blood pressure when you exercise. What matters is the long term benefit.

  39. Hi thee, Just got diabetes, eat no carb or sugar for 3 weeks now. My FBS was 283, now when I test myself in the morn it’s 220-240. As soon as I eat something it drops to like 178. & steady or drops more throughout the day to never as low as 173 so far. Still working on that. But my post meal never spike more then 20 points. Sometimes it only spike 2 points. I try to always snack & morning readings is still high. Fasting about 12 hrs. Please help. Any ideas? Or do I need to be patient, it’s been only 3 weeks. And am I lowering the numbers fast enough? Is hardly any post meal spike more important then the over all high number.? HELP!

    • I believe waking up with high glucose
      is a sign of too much protein;
      get most calories from monounsaturates or mct oil,
      get a little fish oil, and cut back on vegetable oils (omega-6).
      . get most protein from raw yolks
      (Eggland’s Best or pastured eggs).
      . get carbs that increase insulin sensitivity
      like greens and brocolli . puree the hot greens in olive oil .
      take supplements that enhance metabolism:
      carnitine, alpha lipoic acid, Q10, mct oil .
      . if that wasn’t working for me,
      I would see my doctor for metformin (Glucophage).
      google this: metformin

      • PhT, who are you and what is your background/what are your credentials?

        You’re giving out a lot of advice here and IME not all of it is good.

        Be careful what you say to people.

        • . I get the thread is about
          hyperglycemia due to high-stress cortisol;
          but if a person is still not getting results,
          then according to the zone diet’s Dr.Sears,
          high protein will raise your blood sugar levels .

    • It takes longer than 3 weeks, and insulin levels, not transient blood sugar levels are what’s important. Blood sugar is just a down stream event. Hang in there and stick with the program.

  40. In 2007 I was diagnosed with diabetes Type 2, cholesterol of 340, blood pressure 210 over 179. & a liver enzyme count that was headed straight for cancer. I was 57 years old, 5’8 & weighed 223 pounds.

    Luckily for me I spent a lot of time in hippie communes in the 60’s & i already knew a lot about diet & herbal medicine although I had obviously not been applying such knowledge.

    The day I was diagnosed I quit smoking & drinking. I refused all the poisonous meds that the doctors offered me & put myself on a basically vege diet & cut out all sugars hidden or otherwise. This eventually evolved into the Paleo diet which I have been on very strictly for the last 4 years.

    I also started exercising heavily. I had been an amateur boxer & long distance runner in my youth before everything start falling apart in my early 30’s. I started an intense program that has evolved to 2000 crunches 5 days a week, weight lifting twice a week & hitting the heavy bag for 3 sessions of 3 – 15 minute rounds a week. Plus a lot of floor exercise & stretching

    Lastly just under a year ago I took up a heavy intermittent fasting protocol: I eat once every day after fasting between 20 & 24 hours. The results of all this is that I’ve gone from 223 pounds to 142 (what I weighed at 21, I’m 64 now). My diabetes has been gone for over 5 years, I now have low blood pressure & cholesterol of 167.

    I have never felt stronger or had more endurance in my life. The point of writing all this is to let people know that it’s never too late to improve your health. Also, I was never a paragon of virtue & will power. If I can do this as messed up as I was, anybody can.

    Reading the article posted here & the comments got me to write all this as I have never posted on someone’s blog before but this is a terrific site with some great information!

    • Stephen Gordon. Have you ever had a fasting blood sugar problem? I mean high fasting blood sugar?

      I agree with you, intermittent fasting is the best way to fix a diabetes/obesity problem.

  41. I am newly diagnosed with diabetes type 2. I also have high blood pressure. I take nothing for the high blood pressure…and currently on metformin 500mg 1 time daily. When i had a random test two months ago my sugars were 256. Since then i have gone on a low carb diet/high protein. I eat about 25-30 grams of carbs a day. I also walk every day and ride my bike 5 miles every other day. I am 50 pounds overweight. The weight is coming off and the sugars are down dramatically. But not as far down as i would like to see them. My morning is usually around 106, eating walnuts before bedtime helps that. My after meal sugars are usually around 117 to 122 except for dinner which is usually under 140 unless i eat anything with starch- then it zooms near 160. I just cant seem to stop thinking that my morning sugars should be much lower and that i should be seeing more readings in the 90’s. But anytime im in the 90’s which is rare i feel really horrible. I have also noticed that when my period comes thdn my sugars go up no matter what i do and even if i have a simple cokd they also seem to rise a bit. I sleep 5-6 hours a night then nap in the daytime after work. Even on the weekends i cant sleep more than 7 hours. Im so worried that I’m killing myself and that something is very abnormal that even eating a half cup of low carb pasta would send my sugars soaring to 155! I’ve been told that things will get better after i lose more weight…but I’m truly scared about my fasting sugars and the fact that starches of any kind send me soaring. Im 47 and other than being overweight much of my life i dont have any serious health conditions…til now. Any suggestions or info would be really appreciated. Im thinking maybe fasting would help…but of course Im scared to try it.

  42. Hello Mr. Kresser –

    The patients you mention are clearly clinically abnormal, and their results or experiences are not at all representative of those achievable by the general population.

    If conventional dieting strategies do not work for this particular set of patients, its hardly fair to malign IF for not working either.

  43. Can you recommend some instructions re: how to use a glucometer to assess potential blood sugar issues? I’d like to know when I should test, and basic reference ranges.

    I recently began IFing as per PHD suggestions, but I’ve been eating low-carb for nearly four years and have also just begun introducing more “safe starches.” I am trying to understand whether these changes are making things better or worse!

    Much appreciation for this article, and the podcast I listened to today where Chris/Laura discussed various low-carb challenges and possible treatments!

  44. after reading all the comments i have a question: if i have become insulin resistant due to long term fasting and low carb diets- but am not in the pre diabetes stage as yet- is there any way that i can reverse this condition? because frankly, the thought of diabetes really scares me…

    • I believe the answer is “yes, it is reversible”. From reading this post from Peter at Hyperlipid, there are different mechanisms behind what he refers to as physiological insulin resistance (what you experience on a low-carb diet) and pathological changes that causes diabetes.

      On a very low carb diet, your body makes your muscles and other tissues less insulin sensitive to spare glucose for those tissues that absolutely require it (brain, red blood cells, etc.). Once you start eating more carbs, your body will sense the higher availability of glucose and allow your muscles and other tissues to take it up.

  45. okay, this is wierd. i have never had sugar issues before. infact, it almost always was on the lower edge. now suddenly my fasting blood sugar is in 90s. my bmi is good…. so is my blood pressure. my diet is fine as well…. no high carbs or high fats. my h1ac came back 5. last night before going to bed my sugar was 79. yet in the morning it was 96. i dont get it. my peak comes at about 90 minutes after a meal and it is in 120s. so i think my only problem is fasting blood sugar. any suggestions on what i should do now?

    • Hello Ambreen. I recently started IF and I am getting similar results you are. Post-prandial BS is below 85, I eat nothing of course since I am on a fast and take my BS in the morning and it’s 99. I don’t get it. Are you still having this issue or have you found a way out of this by manipulating your macros? Would really like to know. Thank you. — Michael, Tampa FL

  46. I was going crazy with worry before finding this article. I eat low-carb and have been getting blood sugar readings in the 190’s post meals!
    I have been on a low-carb diet for 4 months (less than 25 grams per day). I work-out 45 minutes to an hour 6 days a week (alternating between kettlebells and recumbent bike).
    After a month of this diet and exercise routine (just recumbent bike at first), I bought a glucose meter (ReliOn) and started tracking my sugar levels. After a dinner of spinach salad and chicken and lime vinaigrette, I would consistently see readings of 135 mg/dl an hour after eating, but I wasn’t too worried and would lower the levels with a post meal workout. My morning fasting blood sugar has always been good (mid 80’s). After a 3 egg and cheese breakfast, my levels generally would rise to 115 and fall quickly. For lunch I’d have chicken and broccoli and see 135 an hour after eating. This was consistent for 3 months. I had couple of post-dinner readings in the 150’s, so I had an A1C test done at this point, and it came back normal. My fasting was also normal; my doctor wouldn’t perform the OGTT.
    Then, I started adding weight training to my workout routine via kettebells (love them). Additionally, I started intermittent fasting by skipping lunch at work. My afternoon blood sugar levels are in the low 70’s during this period. I drink one cup of coffee in the morning and another at noon. I eat my normal dinner of chicken and spinach, but now my blood sugar levels are in 190’s a half hour after eating and 170’s an hour after eating. This is not normal. I immediately go and workout to lower them back down, but I really am not eating carbs!
    After reading this, I think it may be attributed to cortisol imbalances from either overtraining or fasting or both. I have a heart condition (LQTS) that requires that I take a beta blocker, which can cause blood sugars to increase, too. But, I really think my issue may be cortisol. As much as I feel good on the afternoon fast between breakfast and dinner, I am going to try to have more frequent small meals or snacks (low-carb and high-protein) to see if I can fix these high blood sugar readings.

  47. THANK YOU! I have been low carb for many years, and after listening to the mainstream of reducing calories, and intermittent fasting gospel, it is good for someone to come out and say hey that doesn’t work for everyone. I even gained weight by eating less and fasting. I am one of those people, the longer I go without eating the higher my numbers go. The problem was also that being I was eating low carb I really wasn’t hungry. Now I have to force myself to eat regularly, this does work for me and keeps my blood sugars below the 100 mark. It would be nice if there was more information out there on this. It is hard after years of being engrained on the the eat less theory that maybe we actually need to eat more.

  48. Thanks for the useful information you are giving people who need to keep their blood glucose level normal. diabetes is a serious health condition and proper dieting is one crucial solution to keep it t bay.

  49. Prolonged fasting or severe calorie restriction causes elevated baseline levels of cortisol. This occurs in conjunction with depletion of liver glycogen, as cortisol speeds up DNG, which is necessary to maintain blood sugar in absence of dietary carbs, protein, or stored glycogen. It seems someone looked at what happens during starvation and took that to mean that short-term fasting is bad.

  50. shredded you are misinformed. It is not a false reading. You have a high fasted glucose level because the low carb has made you insulin resistant. Low carb is bad news for a lot of people and you are one of them!

  51. I did IF and low carb for about 6 months. Prior to that, my fasting glucose was always in the low ’80s. I went for a test in December and it was 96. I freaked out, thinking I was becoming diabetic. Then I read on several sources that prolonged low carb can give you a high fasted glucose level. I’ve heard it’s not dangerous, it’s just a false reading, but it scared me enough to cut out fasting and eat more carbs. I might also add that I gained nearly 20 pounds doing IF and low carb…

  52. I really need someone’s opinion on these hormonal isssues, eating low carb, and IF because I have had some very confusing contradictory experiences, and now I don’t know how and what to eat anymore.
    When I try eating high fat low carb diet tohether with IF (but even without), it always leads me to immediate fat loss (i am a woman with 21% body fat), high energy, glowing skin, no blood sugar issues, and just everything seems great. But after just a week or 10 days, I always encounter some unpleasant effects. Namely: hypoglicemia (for example the other day, after skipping dinner, I woke up with fasting glucose reading of 58, and so I ran for a sugar fix), i get very angry or anxious very often(as if my body is either trying to raise cortisol levels or maybe they re too high already…i dont really know how this works…), I d say it happens especially after a meal of protein and fat (I always eat vegetables, and i have often a glass of wine, so I am far from zero carbs). but it happens also in between meals. Another issue: night sweats and waking up around 3/4am each night (yet it doesnt make me tired). But I feel just very uncalm, I become obsessive, and it is rather a hell. Yet, when I complain, no believes I feel so crappy because it is during these periods that I look the fittest. So then I usually go back to eating pasta and bread, having breakfast. The symptoms disappear immediately. I become calm, I sleep normally, I always start to gain weight. I must absolutely eat 5 times a day food with carbs and protein to avoid shakiness from hypoglicemia. But overall, I certainly feel less energy burning all those carbs then when i have very little (I play tennis competitevily- so I notice immediately whrere my energy levels are). So if it wasnt for all those side effects, I would happily continue eating high fat-moderate protein-low carb. But it just doesnt seem sustainable for me. And having glucose of 58 is even rather dangerous I think. It is probably hormonal issues. When i eat paleo, i become so insulin sensitive that I think I realease too much insulin even just with a portion of fruit and some vegetables. And then the cortisol is obviosly there to raise the glucose to make up for thw catbs I didn’t eat….so I do t know what to do? Should I go back to my standard “balanced” diet of 3 meals (with starches), and snacks inbetween?

    • I agree with everything you say!
      Why don’t you just eat good carbs like veggies. but still follow the protein/fat/carbs diet (but good carbs).
      I think cortisol is a big factor in all this and cortisol regulation is the factor in weather or not your body can handle fasting and low carb. I just don’t think the anxiety and side effects we get are worth it. It is too much stress on the body not eating any carbs. I think everything is so linked… it all gets so confusing!

  53. Also I think it would be worth me using a blood sugar monitor a testing which foods and what amounts keep my sugar levels in the healthy range. As I will do anything to keep those panic attacks away!! They are absolutely dreadful.

  54. Thank you for the article.
    I have hypoglycemia and pcos (hormone issues) and for a period of about 6 months I did fasting for about 20 hours 3-5 days a week. I felt great while doing it, lost a lot of weight! Although one day I started getting horrible panic attacks which I am still suffering from here and there to this day. I believe that it was the fasting, that put such a strain on my body and elevated cortisol levels. Do you agree with this? Right now I kind of follow a paleo, low carb, High protein kind of lifestyle… Thinking this is the best way to keep my hypoglycemia and panic attacks at bay- as they both go hand in hand. My naturopath/homeopath seems to think this is the best way.. Do you agree and what are your thoughts?

    I think fasting is great for those with no sugar imbalances- but I also know that fasting can lead to sugar imbalances! My hypoglycemia was unnoticeable till I started fasting… It was just something the doctor told me I had but I felt no affect from it prior to those months of fasting. So I think people should be careful before entering into fasting as it must elevate cortisol and put a lot of strain on the adrenals and other organs. Now if I feel I need to shed a kilo or two I just eat a very small protein breakfast such as an egg or a small can of tuna, and this really seems to work as eating less in the morning seems to make me less hungry for the rest of the day.
    Sorry for rambling but I would love your opinion!

    P.s just read your article on stress making you fat.. This couldn’t be truer. My body is in such harmony when I have inner peace. The weight seems to fall off no matter what I eat and food digests so easily!

  55. My blood sugar ranges from 84 to 125. Usually anytime I test it, it is around 115 to 125. I haven’t eaten for two days. My sugar began at 135 the evening I began fasting. It was 115 in the morning and 96 that night. It was 114 the next morning and 84 that night. What’s going on is that my liver dumps sugar into my blood in the early morning to fuel my body. I suspect my sugar will be in the 90s in the morning. I think it is important to get one’s sugar down below 85 part of each day – whether it’s before bedtime or when waking up in the morning. Below 85 is when the pancreas stops producing insulin constantly. If you don’t give your pancreas a rest it wears out over the years, and your diabetes gets worse. I need to lose about 15 pounds. I gained 10 over the past two months, and my blood sugar rose slightly as a result. I am beginning to believe that a low fat vegan diet is the way to go.

    • I agree that a vegan diet is the way to go, since I myself have been mostly vegan for some 40 years. Vegan, low fat–no. Vegan plus moderate amounts of healthy fats–yes.

      I still get very high fasting blood sugars, though.

  56. Thank you so much for this article. I started monitoring my glucose two weeks ago and my fasting blood sugar upon waking has never been under 100 – usually in the 110’s. Is this really a problem though? By lunch time, my first meal of the day, it’s back around the high 80s/low 90s.

  57. Would this also explain why glucose readings before going to bed can be lower or the same as when one rises (morning fasting numbers)? I have that problem. (note: I am still learning about this diet and have not implemented it; was following a dietician).

  58. Very informative article. I am following IF with pretty low carbs for weight-loss and despite having pretty low bodyfat, around 13%, I find my fasting blood sugar to be in the 90’s no matter when I test it, after 8 hours, 16 hours, or 16 hours + light cardio. The strange thing is, that even after a high-carb meal, blood sugar goes down to 82-83 or so, and stays there for a couple of hours.
    I have diabetes in my family and am worried I could make things worse with the current pattern of low carb IF + high carb refeeds 2x/weekly.
    I’d like to add in to Ryan’s question about carb/calorie levels during the normal meal pattern test period. Should I also switch to a moderate carb diet and near-maintenance level calories before I check for improvement?

  59. Interesting post. This sounds like it could be the cause for my high fasting glucose. In addition to my high fasting glucose, my total cholesterol has been creeping up, to where it is now over 300 last time I had it checked. Could the high cholesterol level also be caused by excessive IF? I have been using daily IF for well over a year, sometimes one meal a day, along with heavy weight training 3-4 times a week.

    How long does it usually take to see improvement when switching from IF to several meals a day?

  60. is IF not recommended for people with adrenal fatigue? and what if you have cravings from neurotransmitter imbalances. i also have hormonal imbalances. in other words, should people who do not have optimal health be IFing at all?


  61. Chris..thanks for this. Very interesting!
    I’ve been intermittent fasting since July 2011 using the Warrior Diet concepts. Big meal at night, undereating during the day, using whey concentrate and water before and after workouts, etc. I was only 116 lbs when I started and got to about 108.
    My post prandial numbers were fine and my AM Blood fasting numbers were low to mid 80s since I got my glucometer in November.
    For the past week, I have tested randomly in the mornings. I have been getting readings of 70, 73, 78 and today I got 65. This scared me a little.
    I’m wondering if it’s a good idea to go back to 3 meals a day..with some snacks.
    Also, I eat pretty low carb and have been for quite a long time. I’m adding a lot more fat than usual lately since the high fat/mod protein theory has come about.
    Any thoughts? Should I be worried about these low AM fasting numbers and what can I do to correct it?

  62. This makes sense. I doubt if our ancestors would choose to go 12-14 hours without food if they didn’t have to. Fasting is a stressor, and cortisol is a stress relief hormone.

    How do we know that our ancestors didn’t take “snack” food with them on hunting expeditions? (e.g. dried meat or pemmican). I’m sure the more intelligent groups (i.e. the more adaptable and more resilient and the ones more likely to survive and propagate) would have done.

  63. Chris,

    I also wanted to add something to my last post. Sometimes at night my blood sugar will feel low. I will check it and it will be in the 90’s. If I don’t eat anything, I will continue to wake up off and on and feel bad in the morning. If I do eat something then my numbers will be up higher when I check them in the morning. I really want to maintain good blood sugar control but short of not eating at all, I am not sure what to do.

  64. I have been hypoglycemic since I was young. I had borderline gestational diabetes with one pregnancy and had gestational diabetes with another. My endocrinologist told me I was fine after my baby was born when I had a follow up appt. She said I wouldn’t have any problem as long as I continued to stay thin, which I am. A few years ago, I had a blood test for life insurance and saw that my A1c was 6.1 and my fasting was 78 so I knew there was a problem. I have been low carb since then but my fbs now is usually around 90-100. After a low carb meal, it usually stays under 120 but hangs around 98-105 2-3 hours after eating. It takes several hours for it to come down into the low 90’s or 80’s. Do you think eating every 2-3 hours would be helpful? I recently tried pgx for blood sugar control which kept my bs low but I think I had an allergic reaction because I was very itchy. Do you have any suggestions?

    • Cristie – Hi! I wonder what has transpired for you over the last few years since your post. I have had basically the exact same presentation of dysfunctional blood sugar regulation. I rarely run across someone whose story fits mine so closely. Would love to hear what has transpired and what you’ve learned. I wasn’t tested in my first pregnancy at age 31, and ended up very, very sick with HELLP Syndrome. I was borderline gestationally diabetic in my second and third pregnancies. I’ve considered myself “diet-controlled” pre-diabetic ever since. Basically, anyone who has gestational issues has underlying dysfunction and it’s just a matter of time, diet and lifestyle. My numbers have been on a gradual decline over the last 7 years since my first pregnancy despite my fitness, thinness and low carb high protein diet. These days I can’t get my fasting under low 100s no matter what I do. This morning it was 131 and I cried. Anyway, hope you are still getting the email follow-up for this post! Hope you are well!

      • Christie, Amy, are we all the same person? 🙂 I don’t know if either of you are still reading this, but I have a very similar story. After gestational diabetes with my second baby, my blood sugars never returned to normal. I have a BMI of 20, I am fit, I have great cholesterol numbers, I eat a strict low-carb diet. It doesn’t make sense and my doctor has no explanation. For two years now I have been diet-controlled, with my a1c right around 5.6. But my fasting blood sugar, which always used to be normal, is creeping up now into the 90s. I’m just not sure what else I’m supposed to do.

        • Add me as a 4th with the same issue. 😛 I also discovered prediabetes during pregnancy, have had to take out more and more carbs to keep blood sugars low and stable. And lately, they’ve crept up, too, where fasting is ~90 in the morning. It sometimes used to be 70! I’ve read about physiological insulin resistance from a low carb diet, but I don’t think that’s it. When I add carbs back, I feel awful, on that blood sugar roller coaster. I do only eat 3 low carb meals a day–meat, veggies, and coconut oil.

          • Hi, me too. I had gestational diabetes with my second baby, however, it was gone after baby delivering. Last month my a1c test was 5.7! I am prediabetic, but fasting was 68! Then, since i cut almost carbs (sweets, noodle,rice…), my fasting increasing to 100!!!! two hours after one cup of soy milk in the moring, raising to 190!!!
            I have no idea…

  65. you mentioned at front of the article that some IF’ers had high fast glucose, then, listed 90-100 as high? I always thought that was “acceptable”? I’d love to have a fasting glucose of under 100– haven’t had that since I was born.., I think? I was 120 fasting at one time, since have gotten down into the hundreds with IF, and just loosing wt. and healthy life.

  66. I have Crohn’s disease and have been interested in giving my gut more of a rest by intermittent fasting, just having an 8 hour feeding window, the Lean Gains approach. However, I’m flaring and am currently on prednisone, which I know raises your blood sugar and cortisol. Am I making things worse by intermittent fasting while on prednisone? Also, do you recommend IF for people with autoimmune diseases like Crohn’s, or are our adrenals probably too taxed to be doing something like this? What are your thoughts?

    • Hey Cg,

      I, like you, are a crohn’s sufferer, and contemplating intermittent fasting for the reported healing benefits. Currently undergoing a flare as you were and i’d be very interested to know how you got on if you ultimately decided to go ahead with IF.



  67. I’ve been searching long for a discussion on fasting and cortisol/cortisone levels.
    Several years ago I came across published results on the effects of fasting. This was publicised on (ABC Radio National – Health Report) and the Sydney Morning Herald.
    18 hours of fasting each day caused
    production of glucocorticosteroids sufficient to counteract inflammatory responses
    stimulates production of growth hormone
    strengthens the immune system
    With this regime I have managed to control (poly) arthritis in my body. I have a gouty arthritis condition. Stopping this regime brings on severe joint aches and pains within two or three weeks.
    Unfortunately I have developed type 2 diabetes. Together with a previous condition of sleep apnoea and a sleep requirement of 5 hours or less per day has precipitated a complex metabolic outcome for me.
    I continue to fast 16 to 18 hours a day. I feel all the better for it.

  68. I have had “reactive hypoglycemia” for years, and had kept it under control by very careful staging of meals and snacks. My experience is that “intermittent fasting” works BETTER than such staging. I do IF three days a week (20 hours with an eating window of 4 hours). My blood sugar is MORE stable, I have MORE energy, and my mental clarity is better than on the days I eat normally.

    • That’s interesting. I suspect cortisol dysregulation is the x-factor which determines whether people do well or poorly on IF.

  69. Perhaps the reason for the continued blood-sugar control issues in patients going paleo is rooted in under functioning adrenals. I have been following your blog for a awhile and I do not recall you ever addressing adrenal fatigue issues which are rampant in our super fast paced culture. I know that thyroid dysfunction is an area you specialize in and there are many hypothyroid patients that potentially have adrenal fatigue as well.

  70. Thanks for your comment, Paul.

    I think your last suggestion of including fiber and ensuring enough coconut oil during the fast is key. I can see that helping to balance the blood sugars and prevent cortisol – and thus glucose – spikes during the fast.

    It’s certainly an interesting topic and one well-worth exploring further.

    • How is “taking coconut oil and fiber-rich foods like berries and leafy green vegetables during the fast” considered a fast?

  71. Hi Chris,

    It’s a very interesting and complex topic, and great to hear your clinical experience.

    Fasting is a stress on the body, but it is normally a healing stress, because it stimulates cells to exercise metabolic pathways that are damaged in people with blood sugar control issues.

    Like resistance exercise, which is a stress that builds a stronger body, IF can be a stress that makes cells function better.

    So the fact that people don’t deal well with fasting doesn’t necessarily mean they shouldn’t do it. But it’s good to fix diet and nutrition first. A well-nourished body will get the most benefit and the least stress from fasting. (Thus, in our book, fasting comes in Step Four, the last step toward health.)

    In regard to high fasting blood glucose, one should also look at other causes — like very low carb intake. If people eat sufficient starches during their feeding period, fasting blood glucose shouldn’t be elevated by fasting.

    Also, taking coconut oil and fiber-rich foods like berries and leafy green vegetables during the fast can help reduce the stress of the fast, provide some benefits from ketosis, and improve gut flora.

    • How is “taking coconut oil and fiber-rich foods like berries and leafy green vegetables during the fast” considered a fast?

    • Fasting blood sugar dropped to Normal for me on strict LCHF = ketogenic diet, but ONLY after intermittent fasting. Water fasting for five days in a row, 3 times, fixed it for me. Before the fasts my FBG rose steadily, on same LCHF as after the fasts, and I leaned toward explanations like yours, gluconeogenesis and cortisol. Now instead I think the fasting cleared up visceral fats around and inside liver and other organs, enabling their full function again. FBG 80-90 now. Around 110 before. Fung hinted me in the right direction!

  72. Dierdre,

    If you limit your snacks to high-fat, low-to-moderate protein choices, they shouldn’t spike your blood sugar/insulin so much. Eat just enough between meals to keep your blood sugar stable.

    Mike: sounds like a reasonable approach. Let us know how it goes.

    • Hi Chris

      Great post. You mention “blood sugar issues” and irregular patterns, but what are the negative health effects of these? It seems to me that may people learn to live with that without ill effects.

      Look forward to your insights on this.

      Much appreciated,

      • I have had issues with blood sugars for a year now. they drop low, 50-60 and I feel shaky and anxious.
        My fasting Insulin level was 12. I switched over to a paleo diet and now my fasting insulin is <2 (in june) and 4 now.
        My fasting blood sugar is between 83-86.
        My morning cortisol is 10.6
        I have gained 15lbs!
        Oh and my fructosamine is 283 (borderline high)
        my A1C is 5.
        something is not adding up.
        anyone have any ideas?

        I am eating 3-4 times a day and have a snack when I feel I need it, avacado or yogurt.

        typical day
        eggs with greens and pancetta
        decaf coffee with coconut oil/butter and tsp coconut sugar, oh and a bit of whole cream
        steak/chicken and vegetables and olives
        yogurt or goat cheese
        meat and veggies

        • I am pretty sure you are not even counting calories it doesn’t matter whether you fast or not,it is all calories in calories out. Intermittent fasting is only good if you are trying to build muscle while gaining fat

  73. Thanks. I may try it. I find eating to 3 times a day to be so much easier, plus grazing tends to get me into trouble. I definitely have reactive hypoglycemia, and I hated to see them up, so I figured if I minimized eating, even though my net carbs are usually under 30 per day, it would help. This is all very interesting, and there are so many differing points of view. I know that as long as I am paying attention and not following any advice from the ADA, I am much better off. Love your advice on this blog! Thanks again.

  74. Good points! I tried IF for muscular definition, etc, and it did not work initially. If anything, I felt like I had more stubborn belly fat. I am trying IF again now (“leangains” approach). I am careful to keep my (subjectively measured) cortisol levels down and to only IF when I feel like I’m not stressed. I minimize coffee, get adequate sleep, eat properly, then IF. The results seem to be better so far.

    Looking forward to future posts on the topic,

  75. It depends on your pattern. For people with reactive hypoglycemia, they have an overactive insulin response after eating a larger meal, and their blood sugar plummets. Then cortisol kicks in and raises it back up – but higher than it needs to go. This creates a “yo-yo” pattern throughout the day.

    You might try eating every 2-3 hours (small snacks between relatively smaller meals) and test your blood sugar throughout the day to see how that changes things.

  76. Thanks for this post. This is me exactly. Paleo and very low carb, yet higher than I would like blood sugars. I have been trying to do 3 meals a day, thinking that if I didn’t eat snacks, I wouldn’t increase blood sugar post eating and release insulin and would be able to shed that last 10-15 pounds. Is my thinking wrong? I also recently started taking some herbs and cinnamon to try to bring it down.

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