Could You Benefit From Intermittent Fasting? | Chris Kresser
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Could You Benefit From Intermittent Fasting?

by Chris Kresser

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Intermittent fasting is a powerful tool for preventing and reversing disease. Learn how this dietary approach could help you optimize your health.

In previous podcasts and articles on this site Chris discussed some of the factors to consider when deciding if intermittent fasting is the right approach for you. While the decision to use intermittent fasting as a strategy to improve or optimize health should be considered carefully, it is a powerful tool when used appropriately. In this article, I want to discuss some of the potential benefits offered from intermittent fasting.

Intermittent fasting is a general term used to describe a variety of approaches that change the normal timing of eating throughout a day, with short-term fasts used to improve overall health. In other words, the one consistent theme of intermittent fasting is that individuals periodically fast for a longer duration than the typical overnight fast.

Some approaches to intermittent fasting include skipping one meal of the day, extending the duration of the overnight fast to anywhere from 12 to 20 hours. This may also be referred to as time-restricted feeding because it shortens the feeding window. Some people prefer whole-day fasts that usually involve fasting for 24 to 30 hours, performed anywhere from once to twice per week to just once or twice per month. Most of the research on intermittent fasting more specifically uses alternate-day fasting, where participants fast for 24 hours every other day, alternating days of eating without restrictions (1).

Intermittent fasting is associated with decreases in body weight and body fat percentage

Several studies have shown that intermittent fasting is associated with weight loss (23456). While many of the patients I see are more concerned with overall reduction in weight, I also see a lot of patients who want to gain weight, specifically lean body weight or muscle mass. And some of these patients express concern that intermittent fasting may lead to a decrease in muscle mass. Fortunately, research shows evidence that intermittent fasting causes a favorable shift in metabolism that preserves muscle.

Here’s why …
During the most common fasting duration of about 18 to 24 hours, our cells shift from using glucose as their primary fuel source to using fat (789). This means that our fat stores, namely triglycerides, are broken down and used for energy. The breakdown of proteins for fuel does not begin until the third day of fasting. Thus, intermittent fasting remains an option for optimizing health even in those wanting to maintain or gain muscle mass.

Without going into too much of the science here, the shift in metabolism from glucose to fat may be most pronounced after about 18 hours of fasting, suggesting potential benefit from occasional whole-day fasts (8).

Improved cardiovascular disease risk profile

Several studies show intermittent fasting may lead to a reduction of total cholesterol by about 20 percent (724510). This becomes even more impressive when we look at the breakdown of the effects on LDL, HDL, and triglycerides.

The following is an over-simplification, and Chris has written extensively about cholesterol and lipids in the past, but for the purposes of this article:

  • LDL is the “bad cholesterol” (the worst is small, dense LDL, and the less offensive form is large, fluffy LDL).
  • HDL is the “good cholesterol” (we don’t want to see HDL decrease, and most often we would prefer it actually increase).
  • Triglycerides are a type of fat used to store excess energy from our diet, and high levels may be associated with cardiovascular disease and insulin resistance (we want low levels of triglycerides).

Since the total cholesterol on a blood panel is derived from a formula including LDL, HDL, and triglycerides, we want to make sure that a decrease in cholesterol comes from reductions in LDL or triglycerides, and not lowered HDL.

So, what happens to cholesterol with intermittent fasting?

Not only does LDL decrease by about 25 percent after eight weeks on an alternate daily fast, but even better, we actually see a decrease in small LDL particles (101112). And remember, small, dense LDL particles are associated with an increased risk of cardiovascular disease when compared with an equal number of large, fluffy LDL particles. (Note: small, dense LDL is best viewed as a proxy for LDL particle number, which, as Chris explained here, is a more significant risk factor for heart disease than total or LDL cholesterol.) Thus, intermittent fasting favorably shifts LDL both by decreasing total LDL and also by decreasing the small, dense LDL particles.

We also see decreases in triglycerides by as much as 32 percent below levels measured prior to implementing intermittent fasting (271013).

And, as hoped, with intermittent fasting, there is no significant decrease in HDL (14).

Intermittent fasting is associated with decreases in inflammation

A study published this month investigated the effect of intermittent fasting on a marker of inflammation, specifically looking at NRLP3 inflammasome activation (15). The results indicated a decrease in this measure of inflammation with fasting.

Another study evaluated the effect of alternate-day fasting in adults with asthma and found a decrease in symptoms along with striking decreases in markers of oxidative stress and inflammation (7).

Intermittent fasting may improve brain health

One interesting study published earlier this year investigated the effect of intermittent fasting on motor coordination skills, protein, and DNA damage in specific regions of the brain in middle-aged rats (16). This study also measured markers of cell metabolism, cell survival pathways, and synaptic plasticity (you can think of synaptic plasticity as a measure of the ability to learn).

The findings indicated that intermittent fasting was associated with improved motor coordination and learning response and a decrease in oxidative stress (think of oxidative stress as what we often consider “normal” age-related change). So, intermittent fasting may improve healthy aging of the brain and decrease the cognitive decline that is generally considered a normal part of aging.

Intermittent fasting may be associated with decreases in neuroinflammation

Chronic neuroinflammation is increasingly associated with neurodegenerative diseases like Alzheimer’s and mood disorders such as depression. One study published earlier this year looked at the role of intermittent fasting on markers of neuroinflammation in rats and found that this dietary approach actually changed gene expression to allow for an adaptive response (17). These results suggest that intermittent fasting may have a beneficial role in conditions associated with neuroinflammation.

While there are even more potential benefits to intermittent fasting, like improving insulin sensitivity and promoting a normal migrating motor complex (important in preventing SIBO as discussed here), I’ll have to save further discussion for another post to prevent this one from becoming too long. But hopefully at this point it’s clear that intermittent fasting can provide a number of measurable benefits.

Intermittent fasting is not for everyone

There can be risks associated with intermittent fasting, and I would strongly recommend that it be pursued with the guidance of a qualified healthcare provider or nutritionist who understands the risks and benefits and can help determine if it’s right for you.

Intermittent fasting should always be avoided during pregnancy and breastfeeding and should generally be avoided during times of increased stress that contribute to Adrenal Fatigue Syndrome, or more precisely, hypothalamic-pituitary-adrenal (HPA) axis dysfunction.

Additionally, there are health risks associated with diets that are too low calorie, including concerns of nutritional deficiencies, electrolyte abnormalities, and potentially more serious risks if extreme diets are undertaken without appropriate supervision. Intermittent fasting can be a great strategy for weight loss and overall health during the right time for you and when approached cautiously.

Now I’d like to hear from you: Have you found any benefits from intermittent fasting? What type of intermittent fasting works best for you?

Amy NettAbout Amy:  Amy Nett, MD, graduated from Georgetown University School of Medicine in 2007.  She subsequently completed a year of internal medicine training at Santa Barbara Cottage Hospital, followed by five years of specialty training in radiology at Stanford University Hospital, with additional subspecialty training in pediatric radiology.

Along the course of her medical training and working through her own personal health issues, she found her passion for functional medicine, and began training with Chris in June of 2014.  She subsequently joined the California Center for Functional Medicine to work with patients through a functional medicine approach, working to identify and treat the root causes of illness.  Similar to Chris, she uses nutritional therapy, herbal medicine, supplements, stress management, detoxification and lifestyle changes to restore proper function and improve health.

113 Comments

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  1. I have adrenal fatigue and according to the tests I did with my functional medicine my cortisol levels are way to high. Would therapeutic and intermittent fasting make my cortisol worse?

  2. Oh I thought intermittent fasting doesn’t work, but it does. Thank you for sharing the post! This information helps me understand more about intermittent fasting. Gonna find one schedule, which is suitable for myself.

  3. Should intermittent fasting be done while working out? Will it help me lose weight and add muscle?

    I recently did read an article about a guy doing it for a year and it did help him become stronger and leaner.

    What’s ur take on it? Is it risky?

    • I began the year weighing in at 290 lbs on Jan 9th. I weighed in today at 233 lbs on April 7th. Down 57 lbs in less than 90 days. I have fasted every day for a minimum of 16 hours and a maximum of 22 hours. My calorie intake has been max of 2000 calories a day during the eating window beginning at 8AM. I have also worked out on elliptical, rowing machine, and bowflex max (stairclimber) as well as walking for 87 of those days sometimes 2 a day. I have had no fatigue, I have had no injuries or impediments. Oh by the way I am 50 yrs old. Once down to 200 I will add weights workout. I have not lost much muscle ( I worked out with weights in the past) also I incorporate at least 20 minutes of my workouts are HIIT – High Intensity Interval Training on any of the aparatus above. Hope this helps. Best of luck

  4. I have been on an intermittent fast of at least 16 hours every day of 2017. I have lost a total of 40 lbs as of 2-24-17. That is 40 lbs lost in less than 60 days. I realized it was time and had previously lost 40 lbs in 4 months some two years back and then relapsed into my bad habits – There is no ravenous eating as my appetite has me consuming less than 2500 calories a day and for a 240 lb male that is not bad. I alter my fast times based on events and functions but easiest is to follow during the work week. Fast starts betweem 12 noon and 2 PM and first meal of the day is at 8AM. There is an occasional hunger pang at night but it does not carry over to the mornings. Green tea (specifically matcha) is helpful – no cream or sugar. Also I have worked out in the mornings some 35 days of the new year but none all to strenuous. This is the magic bullet from everything I have researched and you would be surprised how many people still adhere to the false belief that they will waste away to nothing. We have adaptive features in our bodies that prevent this as well as multiple bodily functions that are never triggered because we are NEVER in a fasted state including autophagy, HGH production and high levels of alertness as well as preventative measures against Alzheimers et al… Give it a go – start 16 hours per day for 3 days a week – go all work week if you can. Best to do it every day as it gets hard to get back on the wagon after a weekend away. Am measuring my biomarkers after 4 months – had hypertension before this as well as breathing issues and fatigue – Fatigue and breathing issues are gone will test hypertension in April – BEST of LUCK

  5. I lost 10 lbs on a ketogenic diet and another 15 lbs on intermittent fasting… And I’m still losing weight. I eat from 5pm to 10 pm, 1500 calories. 200 of those calories is fish oil. 20 caps might not be healthy long term, but for now the weight is coming off.

    • Hi Lynda, I would recommend Martha Christie’s book on “your own perfect medicine ” she had suffered from chronic constipation all her life and explains in her opening chapter how it all changed permenantly. It will really open your eyes I promise you.

      • Will this book you recommend run through the effects that fasting has on constipation though? I work in the area of constipation and am reluctant to advise fasting in fear that it may exacerbate the problem.

        • One of the reasons I started IF was to help promote regularity of my BM’s. I’ve been experiencing constipation since a pelvic floor collapse 2 years ago. Fasting has made my BM’s softer and regular. Hope this helps!

  6. I try to keep an eye on my weight throughout the year, and use the 5:2 diet only if my weight ticks over a certain threshold. The first couple of fast days can be difficult, but I keep at it because I know I won’t need to do it for long to get back in shape. I find this approach to be very effective.

    • From what I have read about intermittent fasting in the USA bears no resemblance to the yoga idea of fasting I have followed from my twenties. This form of fasting involves preparing your body in advance (say 2 or 3 days prior) bearing in mind the body responds to every thought you have that on such a day you will avoid ALL food, liquid or solid for 24 hrs minimum drinking only water, plenty of it. And if you REALLY want to help your body consume your own urine during the day. It is full of amino acids vitamins, mineral antibodies and strengthen your immune system in the process.(for further info on u/t read Martha Christie “Your own perfect Medicine.

  7. I use IF as a staple choice. I never experienced any troubles. It comes naturally to me. But this is not for everyone. I never get used to 6 meal a day type of a diet. I use 16h fast and 8h feed window. But I also tried Warrior diet and I was fine but IF is for me. Especially for workouts in the gym or on the golf course. I recommend everyone that try this diet.

  8. I have found fasting every other day greatly helps my general health especially my Trigeminal Neuralgia and depression. I no longer take any meds for my Trigeminal Neuralgia.

  9. I’m interested in trying IF, but I’m confused. I always thought fasting was not eating, but everyone talks about eating during their fast. What do I need to do or what’s acceptable? I have a lot of gut issues that I need to fix (hoping that IF will fix them), and I’ve been having issues getting into and staying in ketosis. I’ve been low carb strict paleo for 2 months now but my blood sugar is higher now at 110 than it was when I started at 94. Perhaps IF will get that ship righted as well. Any help would be much appreciated.

    • See my comment read Martha Christie and your problem will disappear her book is based on the most up to date scientific studies or look at ancient Ayurvedic texts.

  10. Living half the year in an 11hr time difference And–Only eating when i’m hungry—has created a lifetime habit of intermittent fasting.
    (I do add 2 this mix B-12 injections and Multiple B Complex injections that I administer myself.)
    How old wld u b if u didn’t no how old u r? I don’t feel any age whatsoevr.
    One of my other habits is workin out and adding a physically challenging sport-few yrs ago it was skiing n now it’s squash (which is addictive!).
    I’m wanting Chris’ expert nutrition as I only have any health complications with food in the US! Lydia Bach

  11. I began a system of IF every other day in early August. On fasting days I did have about 500 calories. I found that I could easily skip breakfast, have about half my calories in proteins for lunch and then sip on juice, fruit, vegetables, etc throughout the rest of the day. It was challenging, but I came to look forward to fasting days. On eating days, I also reconsidered choices. I became ill (probably due to a new immunosuppressant) in early November, so I focused on addressing those issues and gave up fasting. After reading these posts, I think I will launch a new IF routine. Thank you for the information. Any input is appreciated.

  12. Kept looking for a baseline anchorage. Isn’t it implicit that diet during regular non-fasting periods is unchanged in all respects ?

  13. I pracited IF, lost 5 lbs/week for the first month so 20lbs that month. Contunued to lose a total of 50lbs over the course of 6 months, all while lifting weights. I was the strongest I had ever been, and felt better (had better moods) than I ever have. If you wanna lose weight and mostly body fat I highly recomend this. First few days are pretty tough tho.

    • Intermittent fasting really does help in losing pounds of weight. I remember I was watching an interview with Hugh Jackman (yeah, the Wolverine) where he confessed about the hellish diet regimen he used. He coined it “The Wolverine Diet”.

      He told the interviewer that he would eat for about 8 hours and fast for 16 hours. It even went on a water dehydration diet where he deprived himself with fluids just to so he can be as ripped and cut as possible.

      What you are doing right now Brian is totally impressive. It is great to hear that you are lifting weights as well. For everyone who is interested in building muscles fast, check out http://www.musclebuildingmasters.com/

      Thanks for the article Amy. Your contribution to the community is truly appreciated.

  14. I have been fasting for 18 months now and I do once a week 24-36 h. The biggest improvement was that I got of my meds for restless legs syndrome. If I cheat for a week I have to take meds again, so for me I can’t be without fasting! Thanks to Dr Moseley for the tv show about intermittent fasting.

  15. I have heard about IF and I really want to start because of my weight issues. However, I am hypoglycemic and when I try fasting, even if I eat every 3 hours, I am dizzy, tired and cannot function throughout the day. What would you suggest to keep from feeling so hypoglycemic and ‘absolutely starved’ during a fasting day?

    • How can you be fasting if you’re eating every three hours?

      I was on a low carb diet for over a year before I started using IF. I started skipping breakfast two days a week, then having a bullet proof coffee and skipping lunch two days a week, then skipping both breakfast and lunch two days a week, then not eating two days a week, then trying longer fasts (many three day fasts, one five day). I still eat low carb, and additionally I’ve increased my fat content as much as I can per day. Doing this, I’ve lost about another 30 pounds since about March of this year. I like IF so much that I no longer eat breakfast.

    • Anytime you enter into a fast and you get dizzy or light headed, that means your electrolytes are low. especially if you are Keto or Low carb. Its an easy fix, just eat some salt. 1/2 teaspoon, usually chicken or beef broth will do the trick. Takes about 30 minutes to recover. The better approach is to automatically drink the broth when you start the fast.

    • I am also hypoglycemic, I still practice IF when I wanna lose weight. Hint: vitamin waters. They provide your brain with sugar witch is what our hypoglycemic brains need, and I found the IF still works, im assuming because its not solid food.

      • I’m also to the degree that blood glucose swings would cause heart arrythmia. However this was self- inflicted due to a high carb diet which was not usual during human evolution. Adapting to a low carb diet permanently fixed the problem. Its difficult to get large glucosec swings when there are no glucose jolts caused by starch and sugar. I’m probably keto adapted because missing meals or not eating for a day are not an issue. If you eat a species-appropriate diet you really can get busy and forget to eat.

    • Hi Mary,

      Based on the information you’ve provided I would not recommend you try intermittent fasting at this time. It sounds like it could be a worthwhile investment to work with a health care practitioner for adrenal testing, and/or a nutritionist to help you find a strategy that works better for you. You might be able to practice intermittent fasting in the future, but it sounds like right now is not a good time for this approach. You should not feel dizzy or unable to function with IF.

      • I’ve been hypoglycemic my whole life, now 73. Getting light-headed for me is a normal result of not eating often if I eat the traditional American diet. I’ve been tested and I have normal reactive hypoglycemia. You should be tested, very simple, takes about 4 hours. Reactive Hypoglycemia is normal for millions of people, particularly with a North and Western European and Native Indian heritage. If this is the case you need to eat a lower carbohydrate and higher fat and protein diet. Thenyou don’t get light-headed when you fast because your body is adapted to what is its normal mode for your genetic make-up. Instead of running out of fuel you automatically metabolize body fat stores. During WW2 the Partisan couriers of Crete were so well adapted they could run a double Marathon, 50 miles, through the mountain passes without eating or resting. First step is to have your Doc order up the test for reactive hypoglycemia, you may well be just acting normally for your genes.

    • I’ve been this way my whole life and I discovered going LOW CARB first was the key. The issue is your too insulin resistant and you have unstable blood sugar and insulin. Once I went low card I was able to do IF no problem and I feel 10 times better when low carbing or fasting and never have any of the hypoglycemia issues and unless I have too many carbs.

  16. Amy:

    I have tried intermittent fasting and found it works great! I do eat healthfully: EVOO, wild salmon, avocadoes, organic chicken, organic fruits and vegetables. I also drink lots of water and have a “green” drink most days. I typically eat my first meal around 10:00am or so and my last meal around 6:00. My cholesterol levels, triglicerides and glucose levels have been excellent. My question is that I recently was diagnosed with arrhythmia and have an implanted defibrillator. I have to take medications twice a day. I am wondering if I can still do IF and take my meds, too, in a timely fashion. Thanks for your thoughts and your inspiring columns.

    • I have roasted periodically all my life ranging from whole day to several days 1week and.three weeks taking one yoghurt a day at meal times with my family. I have always found it beneficial. I have recently been diagnosed with ITP with a platelete level of 3000 (they should be a minimum of 150,000) I refused further treatment as steroids and IV/ig had no results they had remained at 3000 for some months until I took a 7 day fast with urine therapy and water. This kick started the immune system (ITP is an autoimmune challenge) and they are now rising steadily. The point here is the fasting as urine therapy by itself didn’t do it. I am 75+ been a vegetarian for over fifty years. Had atrial fibrillation for over twenty years but BP of a twenty year old. Fasting enables the body to go into repair mode. Urine therapy returns aaminos.vitamins protein etc etc to the body. Let go your fear and go for it

  17. Thank you so much for this article. I do some IF and will do more from now on, only thing i noticed sometimes when I do IF is that I get cold hands and feet. I would make coffee with some butter and MCT oil or just have black coffee and then occasionally like I said i do get cold hand and feet to the point where it’s two steps away from being uncomfortable.
    Do you have any suggestion on this? Its my understanding that its thyroid issue and that more carbs can usually make it better.

    • Hi Ivan,

      It sounds like it would be a good idea to run a thyroid panel to evaluate if low thyroid function is contributing to your symptoms.

  18. I am a big fan of IF. However, I “cheat” by having about 40oz of coffee with grass fed butter, coconut oil and MCT oil, which allows me to go a full 16-18 hours with no “glucose” fuel.

  19. NOPE! Not for me! I get horrible symptoms from trying to IF. A high fat/low carb diet are also disastrous to my body. I’m surprised so many people here are having such great success!

    • Well…maybe it depends on how you approach the diet. I eat protein and good fats, EVOO, flax seed oil, avocados, bacon, ham, eggs, tuna, chicken salads, etc. This diet keeps me in Ketosis 24/7. All my sinus allergies have completely disappeared (after 50 years of suffering) and I no longer have to take an inhaler for lung inflammation. I also take numerous vitamins and minerals (in pill form) to compensate for not eating fruits and vegetables. I’ve been on this diet for almost 2 years and have had numerous “full work up” blood tests and they all come out great. Since being on this diet my resting pulse rate has decreased from 99-102 down to high 70s low 80s. My cholesterol is great, I have plenty of energy and my Diverticulitis symptoms have completely disappeared. It’s like a “fairy tale”.
      I guess I’m doing something right, I’m not sure how good I’d be doing if I wasn’t taking the vitamin and mineral supplements. I’ve always been slender ad actually had to stop exercising to keep from losing too much weight. The funny part is that on my “old” carb/sugar diet I used to exercise for an hour a day (cardio) and my resting heart rate wouldn’t go below 97/98 (it was scary!!) but on the low carb/lo sugar diet my resting heart rate is much, much better even though I haven’t exercised in over a year!!

      treblig

        • Zoli,
          By “supplements” I’m going to assume you mean everything that is not food?? For example, because I don’t get much fiber I take 4-5 Citrucil tablets with each meal (gotta have fiber). So I’ll list everything I take that is not food. Let’s see:
          Lots of Water
          Calcium 1200mg daily
          Potassium 1100mg daily
          Vit D3 5000IU Daily
          Lots of water
          Magnesium 500mg Daily
          One Adult (over 50) multi-vitamin daily
          Vit C 1500mg daily
          Lots of water
          Flaxseed Oil 3600mg daily
          4 Tbls of EVOO (there are many different ways EVOO is produced/manufactured, do some research and get the cold pressed with the least additives!!).
          EVOO and Flaxseed oil are extremely important in this Caveman diet because these oils (just like avocados) help make your cholesterol levels correct and actually fight the bad cholesterol. You can actually eat much more bacon (I eat 25 strips every morning) because the good oils will negate the effects of the bad oils/fats. Of course…I only buy bacon that has the most good oil/fats and the least bad oil/fats. You also have to make sure you get enough “good” fats/oil because this is what your body will burn instead of carbs/sugar. In the absence of fats/oil/carbs and sugars the only thing left in the human body that can used as energy (fuel) is “protein” and you don’t want to burn protein (muscle).
          If you want to gain weight you simply increase your intake of EVOO, if you want to lose weight you simply decrease your intake of EVOO. Since this a “good” oil/fat it won’t do you any harm, in fact, I think the EVOO is one of the reasons by pulse rate dropped down to normal, along with a BIG decrease in inflammation (Ketosis).
          And with respect to the term “supplement”….I frequently eat an avocado with my evening meal (steak, pork chop, grilled sausage). So in essence, I’m getting even more “”good oils” in my body than listed above.
          And lastly, you also have to eat enough protein to sustain your muscle mass, very important!!!

          Good Luck,
          Treblig

  20. What about decrease metabolic rate as a result of IF and thyroid function. Is it necessary to have a higher carb eat up day to restore leptin and thyroid?

  21. Thank you, Amy. I thought I’d weigh in here, as a woman who’s had great success with IF. I’m 61 and post-menopausal, which could affect things, but my 27-year-old daughter has had similar success, so maybe it’s partly genetic. In any event, I have only bulletproof coffee (Kerrygold butter, MCT oil, and cinnamon) in the morning and am not hungry until early afternoon. I eat when I’m hungry, usually between 1:00 and 2:00 p.m., and when I’m again hungry, usually between 6:00 and 7:30 p.m. Aside from the butter (and occasional cream or cheese), I’m pure Paleo, since February 2013, and have been doing the IF (feeding window approach) since August 2013. I generally run ketone levels between 1.3 and 1.8 mm/dL. When last tested, my triglycerides were 30, LDL 35, and HDL an astonishing 118. I weigh 130 and feel amazing. I’d like to experiment with multi-day fasting (for its potential anti-cancer effects, as my fasting serum glucose tends to run around 85), but even though I’m fat-adapted, when I’m hungry, I’m hungry, and so far I’ve wimped out on dealing with the “pain” of fasting beyond about 20 hours.

      • Not a dedicated meter. The Precision Xtra takes both glucose and ketone strips, which I got online from Canada, as they can be pricey. I do eat fairly low carb, but I’ve never calculated exactly how much. I suspect I’m under 50 grams most days, but I don’t really know. I never eat grains or potatoes at all. But I eat some fruit occasionally (mostly berries), and have red wine at least a few times a week. I often have a sweet potato after my weekly weight lifting (in the style of Doug McGuff), because they are delicious. So it’s low carb, but not obsessive. Clean meats and fish, lots of veggies, lots of good fats, and nuts. I don’t feel deprived; I feel awesome.

    • Naomi – today, I turned 59 and am drawn to your comments for a variety of reasons, not the least being that I long for a generational tribe! How I wish I could ‘pick your brain’ since we seem to be on the same wellness path, although I’m just taking my first tentative fasting steps – and feeling so full immediately when I start eating after a 7pm – 10 or 11 am fast.

  22. I fast once a week. It breaks my weight loss stalls. I am ketogenic also ~ for the last 15 months. Keto makes it easy to fast. I have some much energy when I fast. I do 36 hours fasts, basically I skip a day of eating. I do a strict water fast.

  23. I once did a 35 day fast with just water and the occasional carrot and celery juice bc I was so overloaded with prescription drugs and was not getting any better so Being raised with parents who fasted from time to time and after doing research on how to do it properly, I went on the fast. I felt so much better after and had lost 25 lbs. (I was overwt.) that I was glad I did it. I do not take meds anymore except occasionally and do short fasts from time to time. The way the body heals is to stop dumping garbage into it as does a body of water. Nature heals itself.

    • I would like to know did you eat anything during the day when you did the fast ? As I have also taken lot of prescription drugs and would like to stop them . These doctors here have no idea about anxiety and they are pill pushers ? Please let me know how you did it ? Would appreciate greatly .

  24. I sent a detailed description a day or so ago about my three-months experiences with intermittent fasting, but received no reply.

  25. Great article Amy!

    I was excited and relieved to see the disclaimer at the end for clients that have adrenal stress. I’ve never run an adrenal profile on someone that is NOT under some sort of adrenal dysfunction/fatigue.

    If we get to the IF stage of the nutrition program, I usually make it based around a good dose of healthy fats in the mornings to keep them feeling good, just nothing added to spike insulin levels.

    Keep up the good work!

  26. I am 60 years old with metabolic syndrome. I am also a shift worker. I go from working four 12 hour nights to working 12 hour days with a couple days off in between. Almost impossible to get normal sleep but I work hard at it. About two years ago my weight peaked at 214 lbs (I am only 5′ 4″). I couldn’t walk more than about 50 years without having to sit down and then I developed a very bad autoimmune skin condition. My doctor’s solution was to increase the pills I was taking.

    I started walking about 50 minutes 5-6 xs per week and began to use intermittent fasting along with generally improving my diet. Avoiding processed food and cutting back on sugar and carbs. Because I work 12 hours shifts (and lots of them at night), I would eat a good healthy dinner shortly after arriving at work and then stop eating (but drink lots of water). I would get off shift and go right to sleep so by the time I woke up I would already have been fasting about 18 hours. The only time I got hungry was about 4-6 hours after I ate dinner but that was easy to ignore. It was very easy to do. I would walk before going to work while still fasting and eat when I got there.

    I lost more than 50 lbs. and improved all my blood markers. I got off Lipitor, got a handle on my blood sugar, eliminated one BP pill and cut the other in half. It’s been two years now and I have 5xs the energy. Whenever I start feeling sluggish and start gaining weight I go right back to IF. It’s been a wonder for me. I would recommend it.

  27. I was diagnosed with Graves Disease resulting in I-131 ablation of my thyroid. After some tweaking, I seem stable on daily synthyroid. 2X a week I exercise without breakfast, resulting in a 16-18 hour fast. I feel fine and functional. my doctors are against it, but then, they want me to eat low fat and 1200 calories a day (back to 1950s) but I need to deal with them until new health insurance kicks in. Does the exercise (1 hour of aquafit) really make a difference? I’m not losing weight , but I am finally starting to build muscle after losing so much during the thyroid fiasco…. It’s been a couple years to heal my metabolism.

    • It amazes me how backwards doctors are. A recent study showed that doctors are, on average, 17 years behind the latest studies. The reason? They don’t have time to read new information. Instead, the study found that 86% of over 13,000 doctors in the study, said they get ALL their information from Big Pharma.

      Thats like getting ALL your information about the car you’re buying….from the car salesman.

  28. In addition to following my own nutrition plan, Paleo with some variation, I have been doing intermittent fasting with excellent results. My goals are fitness and reduction of fat %. Right now, I am 57 years old, 163 lbs and body fat around 8%. What amazed me is, I can keep up my training schedule and fast. My workouts are 2-5 hours at a time with a heavy emphasis on the high intensity biking and core fitness burning 2 to 3k cals sometimes more. Sometimes, when I really push the length of my workout, I will drink some diluted Gatorade. However, 90 % of the time, just water. Amazing!

    • Wow, amazing, info, I am still off work sick (1year now), however as I have not used any strong muscles for this length of time and I am still a couple of kilos overweight, and due to my problems I cannot work out (I am doing some exercises at home) where if I have any problems I can stop and rest.
      I was wondering along with starting a new eating programme if Fasting or Detoxing would be good for me.
      I want to return to work ASAP and need to gain strength again to do my job, which is physical.
      My Drs just want to keep me on Meds which have crazy side effects, non of which I take any more. So dieting, changing eating habits, careful exercise, and fasting sound like a way forward.
      Thank you.

  29. I’ve been doing intermittent fasting for about two years now. I don’t do it to lose weight – I’m skinny – I do it to control IBS and associated symptoms. I eat two meals per day – a good breakfast about 7 a.m. and then again around 2 p.m. Since I have digestion issues with carbs and anything sweet – including fruit – I also eat a reduced carb diet. I don’t get hungry as long as I eat enough fat. I’m 62, very active with a farm and I also do constroction work off the farm.

  30. How about using “bulletproof coffee” as your first meal of the day? Does that mimic IF? I feel great when I have high fat coffee just 1 or 2 mornings out of the week and don’t eat my first meal until around noon. I also do morning workouts in a fasted state.

    • Jacqui-I do the same in A.M. since I adapted the Nutritional Ketogenic. I do 20oz BPC in the morning and bring it to work. I wasn’t familiar with this IF till I noticed that not hungry for breakfast till around 1pm. My energy cognitively is sustainable all morning without sluggishness.

  31. I have been reading an interesting book on the subject of diet and heart disease called “Epi-Paleo Rx” and Dr Kruse explains how it is the oxidised cholesterol that is the big issue. He states it is very important to have breakfast and if you are going to miss meals to miss lunch. What are your thoughts? I have been a 2 meal a day person for 30 years yet got metabolic syndrome. When I went to 3 meals a day I felt much better though now I eat mainly paleo.

  32. Does the IF have to be done with regularity to be effective? For anyone who does on-call work (I’m a midwife) it would be hard to keep a set schedule for eating when sleeping at odd times.

    • Hi Mary,

      You can absolutely benefit from intermittent fasting even if it’s done only sporadically. And you’re right to acknowledge that when working such long or irregular hours it can be difficult, and may even do more harm than good, to aim for longer fasts.

  33. Is there any evidence that intermittent fasting could help aid in the treatment of Small intestinal bacterial overgrowth (SIBO)?

  34. I vaguely recall reading that the benefits of fasting may not be the same for both men and women. Were the studies gender balanced?

  35. IF works very well in regards to weight loss, mental clarity, energy and mood for myself. While I agree that you can maintain lean muscle mass with IF, gaining significant muscle requires more precise timing with when one eats or fasts in relation to workouts and their intensity.
    Certainly, working out in a fasted state will accelerate fat loss and convert the body to burn fat as fuel but strength will be diminished in such a situation. Also, post-workout recovery for optimal muscle gain and protein synthesis after resistance training will be somewhat inhibited. This might be a factor of you have a goal of significant gains in muscle or have difficulty gaining muscle. In consideration of these factors, IF can be utilized within a muscle gaining agenda by only partaking in it 36-48 hours after an intense resistance training workout and after proper nutritional recovery and cortisol suppression.
    Personally, I benefit from IF once or twice a week when I train 3 or 4 days a week with the above mentioned time constraints.
    Great article! Thanks!

  36. I IF’d while in ketosis (after 3 or 4 wks) but was calorie restricted also so that I wasnt full after my meal and wanted to eat again rather quickly. I actually got to the point where I wanted more of the meal I was eating. I would try telling myself, just wait for the fat to kick in n you ll be ok. Well then I finally wasnt. IFing got too hard the more I did it, supposed to get easier, rite? I wasnt losing weight, hence the not eating to full. So I just slowly gave up becuz not IFing made no difference. I wasnt super lowcal, did no exercise burning tons of cals. Im pretty sedentary n old so 1600-1800 cal should have been fine. The more I ate as I gave up didnt kick my body into wgt loss either.
    I liked IFing as Im not a brkfst eater but wanting the final meal of the day at 3:30 when youve just eaten a good lchf meal at noon is maddening. Waiting till 5:30 would make me scarf it down and then just be hungry (wanting SUMthing to *chew*) the rest of the day.
    Once in my late 30s I went raw for a number of months, inadvertently going vlc, and quickly didnt eat till 2pm. Then I would stop eating around 7pm. I ate ALOT so i was content I guess, always chewing lol. But the cal count was quite low, as it was all raw, no dehydrated denser stuff, too low in protein Im sure, consciously very lowfat. I just love to eat is my problem I guess.
    But that raw diet put me into fat burning as I could IF and be happy with little fat. Ketosis (lchf) IFing did not.
    Im such a weirdo but maybe someone else, older woman, will see themselves n not feel so ashamed n frustrated with their bodies.

  37. I have not intentionally fasted but not infrequently I’ve gone without food from one evening meal to the next. This is usually due to an outdoor hunting trip or a long day of field dog training without time for a break. Since I normally eat a low carbohydrate diet I think this may be why I feel no urgency to eat during such times because my metabolism is able to use body fat for fuel immediately glucose becomes in short supply. I do suffer typical reactive hypoglycemia and remember getting light headed as one person stated if a meal were missed, but this was many years ago when I ate the typical high carbohydrate diet. As speculation I suspect that eating more protein and fat together with an intermittent pattern of eating may provide necessary exercise to the metabolism. Its only recently that food became instantly available to the human population so we must have evolved for millions of years in an intermittent food regime. Since evolution adapts the organism to suit the environment we should be mighty suspicious that a change in the nutrition environment would not be detrimental to the metabolism, entirely without evidence. It seems that the benefits of the mythical Mediterranean diet were actually based upon data from the island of Crete. However the data was not valid for the purpose claimed for the diet. It was collected during Lent. Crete is a place of devout Greek Orthodox Church members. Such people fast particularly intermittently and usually eat a particularly high fat and protein diet and not what is recommended as a Mediterranean diet. Perhaps it is the fasting which imparts their unusually long and healthy lives. I was recently in Sparta at the conclusion of Lent and the diet then was spit roasted lamb, visible roasting outside in their front yards. I suspect the archaic origin of lean times followed by feasts continued into biblical times when food became more reliably available, but the pattern persisted because anecdotally those who followed it were simply healthier and longer-lived. If we wish to replace archaic belief with science then the science has to be right and we have done an astoundingly poor job in this area, particularly in nutrition science. After a hundred years how could we still be unsure as to whether fasting is good for us? Its left to the few, like those producing this site, to scramble and pick up the pieces.

    • I think becuz IF results in different things for different ppl, even at different times FOR those ppl. The n=1 rules. Always.

  38. I practice intermittent fasting for about a year now. I have lost about 40 lbs (combining with Paleo diet), lover my cholesterol and cut by half a dose of insulin for type 2 diabetes. The only negative side effect of fasting is that my blood pressure goes up, probably because of the stress, I put on my body, during fasting. I don’t know, if anyone else have noticed higher blood pressure. I would like to avoid it, as my pressure is already higher then it should be.

  39. Just a quick question…and I hope I am not repeating something that has already been addressed! But WHAT and WHY exactly are the reasons people, say a friend of mine, 🙂 suffering from Adrenal Fatigue Syndrome should not practice IF? Great article! Thanks!

    • Hi Colin,

      Adrenal Fatigue Syndrome (or as those of use who love being more precise about these things like to call it, hypothalamic-pituitary-adrenal, or HPA, axis dysfunction) is essentially due to too much stress on the body. Sources of stress can be internal and external, whether from inadequate sleep, poor diet, feeling overwhelmed at work, etc. And yes, fasting is also a source of stress. This is where the concept of hormesis comes in. Hormesis implies that at low doses we can receive benefit from something that at higher doses would be toxic or lethal. Fasting too has to be done with some moderation. If the body is already overwhelmed by working 90 hours a week, dealing with a chronic GI infection or heavy metal toxicity, fasting is going to further tax the adrenal glands and potentially worsen the HPA axis dysfunction. IF is best done when you’re able to listen to your body well enough to know when it’s okay to add that additional dose of stress to receive the benefit. Hope that helps!

      • Exactly!
        This is the take home, guys!
        IF should not be stressful. It should aid in recovery, not hinder it. Starvation is not energy building. I tell my clients to pick a day they are feeling great, continue to blow sunshine up your butt and fast for as long as you feel comfortable. If it’s stressful then don’t do it!
        Also, gearing IF for fat loss all one needs to do is drastically reduce caloric intake. You don’t have to eat 0 calories. If you need to eat fewer carbs then do that too but you’ll still shred body fat on rice and potatoes (or candy for that matter) if you’re only eating 400calories during the “fast”.
        I like to schedule a fast and still have people be able to eat unlimited greens, water and sodium. Add whatever protein and fat yiu need to keep your sanity but understand the goal is decreased calorie intake and decreased use of ingested glucose for fuel.
        I’ve exercised intensely on a day where I only ate a banana, salty bone broth, and 6 eggs. I had a scoop of whey and another banana after the workout. Very few total calories consumed but I did have adequate (previously filled) glycogen stores to do the workout). You could do this on varying levels of macros and calories. Getting the requisite fitness levels is usually a good idea BEFORE starting IF for fat loss.

  40. Must read for women:

    I have used IF in the past using a 16hour fast (including over night) and 8 hour feeding window. The first time I did it all I would do was skip breakfast. Then have lunch a snack and dinner. I was not eating Paleo at the time but I would watch my macros a lot so on workout days I would eat more carbs and on my off days I’d eat more fats and protein.
    My body responded very well fat loss wise but my adrenals did not.

    Now I am doing really well with it but I have changed my approach. I eat very high quality real foods. Follow a Paleo diet (once in a while I will add some legumes). But the MOST important thing I have changed is:
    I drink a cup of bonebroth every morning with coconut oil. It’s like my Bulletproof coffee without the coffee. (Coffee really fries my adrenals even top quality) but bonebroth is so healing my body welcomes it with open arms.

    This is what I recommend to my clients. Another option for women is to do IF everyother day. So you’d skip breakfast (or dinner) every other day.

    • Bulletproof coffee or coconut oil – it is a MEAL – not a fasting.
      in my opinion, If you do so, you cannot consider yourself being on IF regimen.

  41. Amy, I regularly fast from 8 am to Noon the following day (16 hours), then a 24 hour fast from dinner Thursday to dinner Friday. It has been wonderful for weight loss, relieving symptoms of depression, and keeps me more alert. One Problem: I had to stop taking a Vitamin C supplement in the morning because I was getting nauseated. Now I take it at lunch and am back on track!
    Thanks for the information and support!

  42. I have found skipping dinner once or twice/week to be the only “diet” I’ve ever pursued that has actually resulted in weight loss. The difficulty with this is the inevitable hunger pangs I’ve felt in the middle of the night when skipping dinner. But if one can handle that, it’s appears to be a great way to take off some weight, not to mention the cholesterol lowering effects mentioned by Chris.

    • I’ve found skipping breakfast and possibly lunch to be much easier for me when I fast. By the time I wake up in the morning it seems much easier to continue the fast as you are usually already about 10 hours or so hours into it and my stomach has adjusted. Hunger pangs (if any) usually don’t start until late morning or right before lunch so they are not disturbing your sleep at night.

    • Hi Kathy,

      There are many different approaches to intermittent fasting. Some people do prefer water only fasts, but some people prefer including fats during the fast. For example, you can add cream or coconut oil to your coffee for some calories and still receive the benefits of intermittent fasting. I don’t generally recommend drinking juice since it’s most often high in sugar.

      • Thanks, I drink coffee with coconut oil and raw cream in the morning and eat again at noon. Would I get the benefits of an alternate 24 hour fast by including this coffee on fast days, or do bbc I have to skip the coffee of those days?

  43. The article clearly states to use with caution if you’re under high stress.
    Morbidly obese, poor nutrition, lack of fitness, high stress and lack of sleep and low levels “happy energy” (positive outlook) are all reasons not to employ intermittent fasting aggressively.

    I’ve seen it work great with overweight people who are prepared and I’ve seen it turn into a disaster for overweight people looking for a quick fix. Get everything else lined up. Eat some healthy food for a month while slowly improving aerobic fitness(walking YES, Crossfit and interval training NO), Lower social stressors etc.
    Don’t continue on ultra low carb for “normal” days while fasting. Eat some healthy carbs and avoid binging on junk.
    Fasting can be a great tool if you use it correctly. Most people who fail with it are using something that would be labeled as starvation. Starvation and high stress is not a good tool.

  44. I have been fasting intermittently for over three years now. I have lost 40 pounds and feel amazing. I continue to fast when I begin to feel toxic or sluggish. If the right nutrients are provided, it’s incredibly beneficial for optimal health.

  45. I have attempted to do longer fasts of 18-20 hours; however, I have only gotten to 17 hours before feeling VERY light-headed and rather nauseous. I was then forced to eat since I was at work and could not just lay down and take a nap.
    What do you all suggest for this issue? I’d LOVE to not eat for a day — that freedom of not having to make choices, prepare, etc would be a nice break, and allow me to get other things done.

    • It’s so nice waking up knowing I am fasting for the day. My day is usually jammed packed and I am MORE productive because I know what I am putting (and not putting) into my body!

    • Laura, The reason you might be feeling light headed is that you might be going into Ketosis. Ketosis is a state your body enters when you stop eating any food at all or stop eating carbs and sugars. When your body uses up all the readily available carbs/sugars it “thinks” that you’re staving. If your body thinks it’s staving it will (as an emergency) go into Ketosis. During Ketosis your body will start to burn body fat thinking that you can not get any food. Ketosis is an emergency back up system to keep you from dying when you go without food for many hours/days/weeks. During the transition from normal carb/sugar existence into Ketosis your body will feel “funny” , some people will get a headache some feel sick. But these conditions are temporary because once your body completely enters the state of Ketosis it can burn body fat just as efficiently as carbs/sugar and you will feel normal again if you don’t eat ANY carbs or sugar!! As soon as you eat any carbs or sugar in any form your body will exit the state of Ketosis (thinking that your getting regular food again) and you’ll feel normal again. I have been in Ketosis for well over a year and actually had to stop exercising because I was losing too much weight.
      Once you get past the headaches and light headedness you can basically live forever in Ketosis. But you do have to eat!! You just have to avoid carbs and anything sweet. Your body will always burn carbs and sugar FIRST if given the chance. When the body is denied carbs/sugar it will automatically “switch” to Ketosis for survival.
      Ketosis is not recommended for Diabetics. However, one of the great benefits of Ketosis is that it floods the body with Ketones! The medical community has determined that Ketones reduce inflammation. On the other hand, the same medical community has determined that “sugar” increases inflammation in the human body!!

      Good Luck

      treblig

    • I don’t know why my username Ryry was auto filling as Johnny t lol.

      Any how,

      I doubt you’re going into ketosis inside of 1 day. It’s most likely low blood sugar and low sodium combo (exacerbated by drinking too much water).
      If you’re bonking because of low blood sugar just make sure you have adequate liver glycogen to get you through the fast. In other words, eat plenty of carbs the day before the fast ir dont fast too often.
      Increased sodium is also a boon while fasting as you’ll excrete it more rapidly on low/no carbs.

      Drink a cup of salty broth (or salt your water) and see if you come back “on line”. If you do them you now know to increase sodium.

      If the sodium alone doesn’t work within an hour then eat about 10gms carbs from some whole food. Berries are great as they are high in fiber too. I
      If you do bonk and want to keep fasting you can restore blood sugar via some quick acting protein like whey or simply have a bite or 2 of fruit. It usually takes very little carbs to get your blood sugar back to normal.

      If you’re going crazy after 8 hrs then you are either way to stressed (eat/sleep/relax more) or most likely need to learn , experience and then rationalize (with a positive outlook) what being hungry really is. It’s ok to feel hungry. It’s not ok to feel like crap.

  46. I have been practicing intermittent fasting everyday for about three months. I never eat anything after 18:00 until 13:00 next day, then I eat a single full meal between 13:00 and 16:00 and a light snack between 17:00 and 18:00. I also exercise everyday using intermittent walking technique (1 minute, all out speed, 2 minutes slower speed) for about 20 minutes/day.I also do exercises every second day with light weights for about 15 minutes/day.
    I find no difficulties with this lifestyle except that I am not losing much weight at all.
    I am not diabetic, have no high blood pressure or heart problems of any kind, and my annual lab results are normal.
    Why am I not losing more weight? I weigh 75 kg, and am 81 years old.

    • Hi Ian you sound one fit kind of guy a man after my own heart. The body is incredibly adaptable and yours has adapted to your routine and functions accordingly. I respectfully suggest to change your routine and fast from 1800 to 1800 once a week or twice once on Tuesday then Thursday the other thing you might consider is looking up urine therapy to apply during your whole day fast. This may sound off the wall but a little research will appraise you of the benefits of this ancient and scientifically proved therapy.

  47. I practiced intermittent fasting for about a year during which time my health declined substantially, esp markers for thyroid dysfunction. My fatigue became so bad that I had to leave my job. Like so many others, I dove into it on the recommendation of a health blogger who did not consider the endocrine system. I now believe that IF might be appropriate for women with thyroid or endocrine problems maybe once or twice a week, no more than that, and I would strongly argue against it without caveat.

    • Hi my two cents:
      It seems that you are not keto-adapted. When your body is used to burn fat/ketones as the primary, fuel long intervals without food are a piece of cake (eh, I mean, a piece of bacon!)

  48. back in 2012 I tried IF. What a revelation! Pounds lost. No issues. Ended up doing 2 x 36 hr fasts per week. Fast forward 2015….not a hope! Menopause has set in & nothing works! I can physically still do it but not an ounce will shift! 🙁

  49. I think it is crucially important to note that intermittent fasting can be more difficult for women and lead to serious hormonal imbalnces and problems. Women’s bodies have different fuel needs in the context of a healthy reproductive system, and if the body thinks there is not enough food, problems may develop rapidly. I actually have successfully practiced Dave Asprey’s version and suggestions/biohacks regarding intermittent fasting on most days of the week for quite some time; however other women close to me, my sister included, have had a lot of difficulty with fasting, even with high fat hacks in the morning. While it is clear there are some awesome benefits for many people, I have seen that it is certainly not a one size fits all approach. There is lots of information available to those who are interested online. Dave Asprey is very clear that women need to proceed with caution, and has a great post entitled A Bad Combination for Women: Intermittent Fasting and Paleo. He cites Stefani Ruper of Paleo for Women and I found the article she wrote to be very helpful!

    • Thanks for pointing this out and suggesting additional reading. I was surprised that, given how much I generally appreciate Kresser’s blog, there wasn’t more information about women-specific issues with IF. I understand he needs other people to write content to keep his page views up, etc. but hopefully increased content can happen without decreased quality.

      I also am very cautious about recommending IF to anyone who has struggled with disordered eating in the past.

  50. Amy, you stated, “(Note: small, dense LDL is best viewed as a proxy for LDL particle number, which, as Chris explained here, is a more significant risk factor for heart disease than total or LDL cholesterol.) ” Did you mean, “…elevated LDL cholesterol was more of a proxy marker for elevated LDL particle number….,” which is a quote from Chris’ article which you cite?

    • Hi Diane,

      Hopefully I can clarify this a bit more here…

      There remains some controversy as to which measures of LDL can best identify people at increased risk of cardiovascular disease (CVD). At one point it was generally accepted that small, dense LDL particles are inherently more atherogenic than large, buoyant LDL particles. But now several studies have shown that small, dense LDL particles lose their predictive value when adjusted for LDL particle number. This means that LDL particles don’t have to be small and dense to increase CVD risk.

      Here’s one study that discusses this in a bit more detail:
      http://www.ncbi.nlm.nih.gov/pubmed/15296705?access_num=15296705&link_type=MED&dopt=Abstract

  51. Fasting works, I’ve done it myself, family and patients. The only time I run into trouble is with very obese people especially women, when they fast, the toxin release and stress can get them violently ill. They have to do it on a very gradual level with lots of support, especially from the family and probably under the guidance of a naturopath, as they do need lots of adrenal support.

    • Does anyone know how we can tell if our adrenals are under stress? My naturopath does a test with a string that she slides down your throat. I cannot do that!

      She believes I needed adrenal support, so I took the remedy she suggested, but I noticed no change at all.

      I just started IF a few weeks ago. My energy level has plummeted. Physically, I’m very healthy, but lately, my depression has been at an all time low. Today, during my weight training, I felt dizzy, fatigued and out of breathe. Not sure if it’s because I hadn’t eaten for about 18 hours or not.

      • You could have methylation issues so you can’t clear toxins released from fat when fasting or there’s always heavy metal toxicity. A good naturopath should be able to figure it out. I’m just a simple medical doctor, we don’t train in this stuff unfortunately. I had to learn all on my own.

        • Kudos to you Dr. Jeff you’re a smart man! I wish I had a Dr. who would do a bit of research outside of prescribing me medications. I’ve been on asthma meds for a few years now with no hope in sight 🙁

          Hey maybe you can help me with something.. I’ve been doing the ketogenic diet for a couple months now and have also been taking the cutting stack supplements from http://legalsteroidresearch.com and I’m down to about 6% body fat. I’m wondering if it’s healthy to stay that lean? If I go off the supplements I think my body would go back to 8% or 9%.. what is the ideal “healthy” range for my body fat levels?

          PS – I’m trying to stay quite aesthetic since I want to compete in fitness modeling.

          Thanks for your time sir!

          -Jake Peerson

  52. So I have all the symptoms of HPA axis dysfunction except for one – I am morbidly obese. Should I try intermittent fasting? Could there be ways I could modify it so that it would work better for someone with adrenal issues? Like the bulletproof coffee method, and maybe adding some collagen protein to it. I realize that’s not technically fasting but do you think I would still reap some of the benefits?

  53. Amy, you wrote,

    “A study published this month investigated the effect of intermittent fasting on a marker of inflammation, specifically looking at NRLP3 inflammasome activation (15). The results indicated a decrease in this measure of inflammation with fasting.
    Another study evaluated the effect of alternate-day fasting in adults with asthma and found a decrease in symptoms along with striking decreases in markers of oxidative stress and inflammation ”

    Did the study consider whether the decrease in inflammation was a result of Ketosis (Ketones in the body that fight inflammation) or a result of not eating foods that are inflammatory to the test subjects??

    treblig

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