Is Intermittent Fasting Healthy?

If only I weren't so skinny!

One thing is certain in the field of health: what is common wisdom today can easily become “misapplied science” tomorrow. What’s “in” this year may be “out” next year. Often it’s hard to arrive at the right answer.

For example: Oily fish is good for you because the Omega-3’s are so healthy, but oily fish is bad because it can be contaminated with heavy metals, but oily fish is good because recent tests prove it’s not actually very contaminated, but oily fish is bad because the fishing industry paid for those tests…you get my point.

The Fats vs. Carbs argument is another. So when a reader recently asked about regular fasting as a means of maintaining good health, I had to re-evaluate my point of view slightly. What I found surprised me and convinced me to add a new twist to my ongoing health-and-anti-aging regimen. It’s called Intermittent Fasting – or IF.

Twenty years ago, as I was first forming my Primal Health point-of-view (based on a model of how humans evolved), I found it very easy to embrace the concept of “grazing” that seemed to represent the collective conscious of the weight-loss-and-health movement at the time. After all, eating several small meals a day – grazing to maintain even blood sugar and to avoid having your body go into starvation mode and start hoarding gobs of fat – seemed to fit my picture of early humans roaming the plains of Africa foraging for roots, shoots, nuts, berries, grubs and the occasional road-kill leftover from a hyena feast. The explanation that we in the weight-loss business gave the public was that by maintaining this steady supply of protein, fats and carbs throughout the day we would never experience a wild swing in blood sugar due to rapid rises and falls in insulin, therefore we would be less inclined to store fat and more inclined to burn off our existing fat stores. Heaven help us if we skipped breakfast, overate or starved ourselves periodically. That would surely wreak havoc on the delicate hormonal systems keeping us in homeostatic balance.

Well, maybe not.

The truth is, many people have succeeded in losing weight and keeping most of it off using this simple grazing method, which consists of eating 5 or 6 small meals or snacks spread evenly throughout the day, with no single meal exceeding 600 calories and where each meal or snack contains a little protein. This grazing method is the ultimate in portion control: take the 2400 (or more) calories you might otherwise scarf down in 2 meals and simply spread them evenly throughout the day. I think it’s reasonable to project that many more have avoided or postponed getting type 2 diabetes using the same method.

But like many behaviors in the fitness and health world, there comes a point where the benefits decrease and we find ourselves on the dreaded plateau.

The first thing most people will tell you about their attempts at grazing is, while it usually works well if you are diligent, it’s pretty difficult to stick with, since you need to be near a source of quality food every few hours. If you work at home most days as I do, it’s not a problem, but it can make life difficult if you work in an office setting or happen to be a road warrior.

The next common issue is that after a few months of progress, you arrive at a frustrating point where the weight stops coming off, the initial high energy levels decline or you stop building muscle. That makes sense from an evolutionary perspective, since the body is so well-tuned to adapt to any situation – including a perfectly even flow of nutrients. In this case, the body’s reaction to this steady supply of nutrition is to actually decrease insulin sensitivity. It “knows” there will always be food, so it “down-regulates” insulin receptors, and probably down-regulates other metabolic systems as well.

In my Primal Health articles here at MDA, I am always looking at ways we can harness our DNA blueprint to maximize health. I like to see how we can shake things up a little and trick the body into burning more fuel, creating more lean muscle, repairing cell damage and staying injury- and illness-free. So when my 79-year-old buddy Sid at the gym started raving about his weekly 24-hour fast over a year ago, and my friend Art started writing about his own fasting experiences, I decided to look into it further.

The results were surprising and impressive.

Numerous animal and human studies done over the past 15 years suggest that periodic fasting can have dramatic results not only in areas of weight (fat) loss, but in overall health and longevity as well. A recent article in the American Journal of Clinical Nutrition gives a great overview of these benefits which include decreases in blood pressure, reduction in oxidative damage to lipids, protein and DNA, improvement in insulin sensitivity and glucose uptake, as well as decreases in fat mass.

How can you argue with results like these? And it all makes sense from an evolutionary perspective, because our predecessors almost certainly went through regular cycles where food was either abundant or very scarce. The body may have established protective mechanisms to adapt to these conditions by sensitizing insulin receptors when it was critical that every bit of food be efficiently used or stored (as in famine), or by desensitizing them when there was a surplus, so the body wouldn’t be overly-burdened by grossly excessive calorie intake.

Beyond insulin sensitivity, it appears that caloric restriction and intermittent fasting may “turn on” certain genes that repair specific tissues that would not otherwise be repaired in times of surplus. One could surmise that this adaptation serves to allow certain cells to live longer (as repaired cells) during famine since it’s energetically less expensive to repair a cell than to divide and create a new one. That might help explain some of the extended longevity seen in animal studies using caloric restriction and/or intermittent fasting (read about here, here, and here). Intermittent fasting has also been shown to reduce spontaneous cancers in animal studies, which could be due to a decrease in oxidative damage or an increase in immune response.

So, what are the practical applications of this research?

It depends. There’s probably no right answer (remember what I said at the beginning!) Art suggests mimicking the experiences of our ancestors, which is to say don’t plan any fast, just surprise your body every once in a while with 24 hours of little or no food. My friend Sid does his fast every Tuesday like clockwork, so he has a light final meal on Monday night and doesn’t eat again until Wednesday breakfast. He does drink water and a little juice on his fasting day. Some fasting programs suggest you take a two-week “cleansing” approach where you eat regularly every other day and fast (or eat 40% of normal) on alternate days for two weeks twice a year.

One thing that is most interesting about the intermittent fasting studies is that slightly overeating on the non-fasting days (to make up for the lack of calories on fast days) yielded similar results, so it wasn’t so much about total calories as it was about the episodic deprivation.

As for me, I’m going to try the once a week deal, but I’ll start by no longer agonizing over a skipped breakfast or late dinner. What I used to think was the end of the world might just be the beginning of a new one!

Let me know of your own fasting experiences.

UPDATE: See this post on Women and Intermittent Fasting.

Further Reading:

My Carb Pyramid

Healthy Recipes

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About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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439 thoughts on “Is Intermittent Fasting Healthy?”

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  1. I used to do (once upon a time!) papaya juice fasts for 24-48 hours. While my whole system seemed to enjoy the “rest”… I dont think there were any long term beneficial results.. I think intermittent fasting is good for head and heart

    gp in montana

    1. My fasting experience has been successful. I did it three or four time a week. I know some people did it once or twice a week, but still achieving good results. March marks the 5th year of my IF. I lose weight, stay fit and feel much healthier than before. Though more people should go on the IF way of eating.

      1. Just remember NOT to fast right after an intense workout and do give your body a chance to recover completely before start on a fasting program.

        I agree with some of the users in here that drinking juice on a short fast is NOT ideal since your body will think you are on a low calorie-diet instead of really fasting.

        I fast on water/herb teas once a week on a Sunday for 24 hours starting after lunch until noon on Monday. Again, the reason for Sunday since it is a quiet day for me and I have done my intense workout during the week, which my body completely recovered by then.

        I alternated between drinking hot water with lemon and herb teas throughout the day. The kind of herb teas I drink are detox teas like kidney cleanse, liver cleanse, artichoke leaves etc.

        I break my fast with a vegetarian protein shake, which consist of two tablespoons of organic brown rice sprouted powder (85% protein digestibility), two cups of coconut milk, one tablespoon of wheat grass, a large ripe banana or pear and a handful of baby spinach.

        Cheers from Karl 🙂

        1. Great explanation, thank you so much. I am starting a once a week 24 hour fast. I will be traveling so will bring along teas and citrus for my water.

      2. Just curious what your IF schedule was like. I just started learning about IF, I would like to give it a try I just don’t know what to do. Thank you in advance.

    2. This is interesting, because I have always been one of those people who can’t not eat for longer than a few hours. I my stomach would literally rebel if I didn’t eat, and I wouldn’t then be able to eat without feeling super sick and crampy in my stomach. Lately, I have been intermittently going for like 12 hours without eating, because I have time and access to good food in the mornings, (wake up at like 5 for breakfast), and after about 1pm I usually stop eating until 10pm, sometimes I don’t eat from 10 to 10, and I have found that it doesn’t hurt me like it used to any more, and I have been surprisingly ok with it. However, with workouts it seems to make me lag when I haven’t eaten.

      1. I lIke the additions to your book and I lenraed some new things that were very useful.However, I was surprised that you made little mention of autophagy-one of the major advantages of IF. Of course autophagy might mean more to me than you as I am close to 70.I have done a link chase on autopphagy and there is a wealth of information available. Based on that information, I use IF to do cell hardening, strengthen muscle cells and to kill random cancer cells floating around in my body. There is enough information available to justify a chapter in yet another edition in your book when the time comes.Otherwise, congratulations on your great work.

      2. Hi bud just seen comment and taut would give some advise. Most of your IF should be done while sleeping to make it easier and fasting like 16 to 18 hours each day. What i do is wake up skip breakfast like half 2 i hit the gym so i eat a wholegrain bananna sandwich to carb up and have some energy for the lifts , then have your protien and a small dinner and then at half 6 or 7 have your main dinner and thats your fasting done wait until next day to start cycle over again. And like commented above on your off days (non working out) kind of carb cycle so during the eating period avoid your carbs and you can stack up on your juices through out the day while body is in recovery mode. Hope this helps

        1. Thank you for your input. Your explanation makes the transition achievable. Just to clarify, is it best to eat prior to a workout to maintain best results? I’m an early riser and prefer my training in the mornings which would be prior to the completion of the fast for that day.

    3. There seems to be a great deal of confusion about the idea of fasting… With the so many variables at work, it seems that one beneficial step for fat loss (fasting after a workout to increase growth hormone release) would also be detrimental for muscle-building/retention (a catabolic state due to muscles being “starved” for food). Perhaps the best approach is to see what works for you, evaluate and measure your progress, and tweak appropriately.

    4. The problem with juice fasts is you are still taking in massive amounts of sugar, thereby negating any health benefits

  2. I knew a guy who did a juice fast one day a week. He said it cured his sleep issues and gave him greater mental clarity. Haven’t ever tried it myself. I’m way too much of a foodie. 🙂

    1. i had similar results…with 48 hour fast…..There is actually some research that say fasting helps de-calcify the pineal gland….basically helps it reset and get all the fluoride and other crap out of your pineal gland.

  3. Only problem with a juice fast is that you may be defeating the purpose. Many forms of juice are high in sugar and might lull one into thinking they are fasting when they are not really. I think you have to achieve that true low blood-sugar state to start prompting the desired changes.

    1. Yes, fasting means water only. The moment you take in any external calories you break your fast. Then it becomes a low calorie diet not a fast. Juices are loaded with calories.

        1. Personally I find that drinking tea (no milk/sugar of course) or black coffee does not upset the fast the way juice or other caloric substances do. I just spent several weeks eating one meal a day (except sundays) and felt great by the end; to help me get through that last stretch before the meal I would drink coffee, and it was a nice boost, didn’t destabilize me like calories did. (I felt especially good the week I did zero grains – my main food was almond butter.)

      1. home-made vegetable juices would seem ok, e.g. cucumber and celery

  4. I can personally attest to IF working wonders. Most people especially in the gym are so brain washed into thinking they need protein every 2-3 hours or they go into a catabolic state and wither into nothingness. I say the body is smarter than that and can do with what you give it.

    Personally I do a daily fast and only eat from 1-7pm taking in enough calories that I would normally take in and focus on lots of protein, quality fats and vegetables. I mix in some carb up days whenever I need them for a more explosive activity such as playing ice hockey.

    So far I have lost 10lbs of fat, gained 5 lbs of muscle and hover at around 8% BF. I have plenty of energy in the morning to do a strength workout 3x a week and add in some walking and hiking. Needless to say I had to see for myself and I did not lose any muscle during the fast but rather gained and lost fat. I am sure my LDL and BP have gone down, I have more focus in the AMs with only a cup of coffee (and I only need one to last me a whole day) and my life does not revolve around food and I enjoy my meals when I have them.

    Best part is IF is a lifestyle, not a fad fast. You can do a 16-18hr fast daily(like I do, 24 hr fast 1-3x a week, or just fit it in whenever. That’s not even to say the healing powers of fasting go back 100s of years.

    Sorry for the long post, but as a fitness professional and working with many people with chronic illnesses, I can’t stress this lifestyle enough.

    1. Quick question Mike -Will taking ACV with water during my fasting period affect the quality of my fast?? Normally I stick to water and black coffee during my non-eating time, but have been trying to incorporate some ACV into the scheme lately and it suddenly dawned on me that i have NO idea what affect that would have on my blood sugars… thanks!

    2. Thank you for the long post mike! I was curious if it was healthy to do this on a daily basis as most posts only seemed to focus on a “once and a while” or once a week basis. As a new father, student, and having 2 jobs, this way of eating is so much easier for me then the every 2-3 hours diet. I started last night, eating a normal healthy dinner about 12-14 hours before I knew I would be training the next day. I must say that I couldnt be more surprised at my energy level and stamina during my intense 12 mile bike and hike.

      I will be sure to post back after 2 weeks with my results. Feeling great right now!

      Thanks for everyones advice and input.

    3. You sound you got off to a great start. How are you maintaining your goals since this last post? That window for you fast is the one I will try, any tips regarding how to stick to a clean lunch when bringing it from home?

  5. sorry just to clarify too, it’s not a reduced calorie/calorie restriction diet, it’s just a smaller window of eating with the same healthy calories (within 10%) I would normally intake in a day. Also the fasting is strict water and only coffee for me, no sugar added. I also add in some apple cider vinegar and fresh lemons during the water fasting periods.

  6. Mike
    That sounds worth it! I believe i’ll give it a try, thanks for sharing how well it works, i’m convinced. Oh, i always drink water with a fresh squeezed lemon after a good work out.

    I have a friend that did drank juice for her fast. She did not complain about being hungry, it didn’t bother her not eating, You’re right, it does defeat the purpose. I told her i did not think drinking juice was a “fast” that she was just sacrificing eating.

    1. I think that drinking juices and more so mineral based beverages are essential to physical health. keeping in mind that a certain amount of natural sugars are very good for the body. you may choose a more deprivation based fast but the body needs some form of nutrients in order to survive in a healthy manner. I started my fast two weeks ago. I only eat twice a week within a 24 hour basis and plan to go the entire month as a starting point. yes it doesn’t sound but so interminent but i find that my body does need these vitamins. i tried only on water and the effects were not favorable. nonetheless i think anyone at least trying a little deprivation in an overindulgent/obese country is admirable in there actions to break societies’ poor habits. anyway…the fast feels great and i encourage anyone to try as within reason.

      1. Megs
        Please be careful. What you are doing is definately not healthy. Even Alternate Day fasting is hard on the heart:

        “This is not a positive report.

        CONCLUSION: Chronic ADF in rats results in development of diastolic
        dysfunction with diminished cardiac reserve. ADF is a novel and unique
        experimental model of diet-induced diastolic dysfunction. [!] The
        deleterious effect of ADF in rats suggests that additional studies of
        ADF effects on cardiovascular functions in humans are warranted.”

        Ahmet I, Wan R, Mattson MP, Lakatta EG, Talan MI. Chronic alternate-day
        fasting results in reduced diastolic compliance and diminished systolic
        in rats. J Card Fail. 2010 Oct;16(10):843-53. Epub 2010 Jul 1. PubMed PMID:
        20932467; PubMed Central PMCID: PMC2953475. ”

        Please, Meg, reconsider and reinstitute at least 5 days per week of 2000 calories. Two days of water/lemon fasting per 7 day period is plenty for quick weight loss.

        1. been fasting three days a week for three months– maybe lost a pound. on my eating days, it was maybe 1300 cals of very healthy foods. I run about 10 miles week. I’m about 190 at 5’4″ 34″ waist (rolly polly) very healthy, never get sick— just meant to be chubby I guess? before doing three days a week I was doing two for nine months– didn’t loose then either. I started two years ago with Tuesday fasts and daily 1200 cal days. over two years lost maybe 10 pounds? I’m close to 60, so maybe that’s it? people say I look early fortys, and that’s the way i feel— just thought by now I’d be.., maybe, 170?

      2. That is not the type of fasting we are talking about. Eating only twice a weeks is starvation not fasting; however the compressed eating window or one or two 24 hour fasts thrown into the diet is healthy.

        Furthermore, your dogma sounds extremely pro-ana to me, being a recovered anorexic(26,4’7,134lbs oh healthy!) I know the kind of things we come to beleive. This is not deprivation for the sake of deprivation, it is about health but it is a fine line.

        Please do a little more research on the difference between intermittent fasting and eating disorders.

  7. I’ve fasted for 24 hours on water only. I do feel better. Monday night to wednesday morning may be difficult. An easier 24 hr. fast would be to quit eating on say Saturday 2:00pm and eat again 24 hours later Sunday at 2:00pm. It seems easier, anyway.

  8. Hi Mark

    Inspired by Art Devany, I’ve been doing IF for a while now – combined with a low carb / paleo approach – and find it is realtively easy to stick to. I’ve leaned out a little bit from it and it actually frees up time from food prep.

    Eades wrote about this earlier int he year on his blog too.

    The method I use is typically to eat only in the evenings – like the Warrior diet or It is realtively easy to eat nothing during the day and feast at night. Loren Cordain had an article on this in his paleo newsletter a while ago

    saying that the evidence suggested that typically hunter gatherers would tend to eat big once a day. Which is sensible when you think about it – life was feast and famine in general and this approach mimics the same hormone drives.

    IF you search pubmed for “intermittent fasting” there are loads of interestig articles. There are a few on my blog too.

    1. How does that affect your workouts? Do you exercise in the morning on an empty stomach?

      1. I don’t know loads about IF, but I’m curious enough I may try skipping breakfast. I did, however, used to run in the mornings before breakfast. I was a bit more into mileage back then than I am now, I can remember going for 6-8 miles before breakfast. Seeing as primal workouts are less demanding on glycogen stores, I can’t see it taking that big of an effect.

      2. Lot of people do this, Chris:

        – fast from 6 pm till noon (your body will do a cleansing during this time, and start cleaning out old broken cells)
        – exercise vigorously at 11 a.m. or 11:30 a.m. (right before you break the fast)
        – then have a big healthy meal at noon, right after exercising (it needs to be within a half hour) (your body will use the nutrients to rebuild, repair and rejuvenate)

        If you do it this way it’s important not to eat anything before you exercise, but eat very healthy foods (lots of healthy fats, carbs and protein) right after exercising.

  9. I read it too fast and thought it said Intermittent FLASHING. Keep’in cool in the summer!

    Seriously, as I initiate a dramatic change in lifestyle to a Primal Diet, I have attempted to IF in the evening and it is too difficult at this time because of the already drastic reduction in caloric intake.

    However, I am able to sustain on a High Protein Shake (Meal Replacement) at 5:20 AM until a 12:00PM lunch weekdays.

    Honestly, I am not ready for any food consumption that early in the day. Shake and DCMF for breakfast.

  10. While I think that intermittent fasting is reasonable within the context of how we evolved and life prior to farming, I do have one caution. If you are susceptable to gout you may not want to fast or try it in short bursts and build up to longer ones. I’ve had a gout attack flare up practically every time I’ve tried this (voluntarily or not). Fasting tends to increase uric acid levels and increase your risk of having an acute attack. That said, losing weight will significantly lower your risk for getting gout so I am working on lowering my weight and taking the med’s necessary to stave off an attack at the same time.

  11. I was doing a shortened eating window like Mike OD up there (MOD, is that you?), but was having trouble getting in enough calories in a 4 hour window. I’ve since switched to a 24-on, 24-off plan and I’m enjoying it. I don’t have to gorge as much to get enough food, I don’t have to feel overstuffed, and I can maintain my bodyweight and activity. I’m doing 6:30pm to 6:30pm of fasting and then 6:30pm to 6:30pm of eating, usually four meals (dinner, breakfast, lunch, light dinner).

    Scott Kustes
    Modern Forager

  12. Michael Eades had some great write-ups on IF’ing earlier this year. I’ve been doing low-carbing (which had already become second nature) with 18/6 IF’ing since then. All you have to do is skip dinner or breakfast most days (no snacking!), which is pretty easy if you’re working.

    1. I definitely agree with this. Sometimes I’ll keep lunch too but I don’t make it a job. I just about always keep breakfast, I’m use to it now. But I decide at the time if I was to keep lunch, if I feel like eating, I eat. I just don’t make it a job or chore. Stress free as possible. I’m doing this in combination with the starch solution and it’s doing wonders for me already. I have been doing the starch solution for the last month and added IF for the last three days. My knees have been aching for at least the last two years. It’s gone! as inflammation in my arms has decreased to hardly noticeable and this is from hardly being able to move it on some days. I thank god for wisdom. Give up the meat and dairy people!

  13. I like what’s called low carb in this context. I’m referring to an earlier post where Mark describes a lunch salad. I like eating this way. I don’t know if I have my food/energy level dialed in or if I’m just more naturally aware I’m in need of a nap (no constant supply of energy coming in). Anyway, the post has inspired me to fast, today. I’ve done it irregularly (which is the right way I hear) from reading Devany’s blog.

    What kind of exercise are people considering on fasting days? Mimic the ancestor and walk a lot like I’m in search of food? Maybe an occasional run and throw a rock like I’m aiming for small tree rodents?

    I normally do 3 exercises (from a mix of about 30) at high intensity 2 to 5 days in a given week. I’m skipping that stuff today.

  14. After reading about this last Fall, I started doing IF, and have continued to do it with good results. I generally eat from about 6pm to 10pm at night and fast the test of the time. It is a good weight-management tool. After loosing some weight initially, I’ve stayed pretty steady for the last 5 months. This of course is without making any concerted effort to lose, but it sure is nice to not have to worry about how much I eat or even what I eat, as long as most days I eat what I feel is an optimal diet for me healthwise. So I wouldn’t say there’s no plateau for IF’ers. I think there are plateau’s for just about any eating plan. But I also think IF makes it very hard to regain weight and also potentially has some great health benefits on top of it’s facility in helping one lose weight.

  15. It was nice reading the posts. I have started this way of eating two months ago and have noticed incredible results. Mostly, I fast for 19 hours and eat in a 5 hour window. I have lost weight and inches, have more (lots more) energy, sleep better and seem more alert. Generally, I eat whatever I want to in my eating window, but since the weight loss has slowed down, I am considering making some modifications and lowering my carbs. A couple things I noticed–the flavors of all foods seem more intense, so be prepared for fruits to seem too sweet, and be careful to taste your food before adding salt.

    You asked about exercise…well I will be 69 tomorrow, work full time and exercise 5 times a week. I do yoga 3 x and work out at a gym with a private trainer 2 x. I do all of the exercising in my fasting mode and have had only one time that I dot dizzy when going from lying down to standing quickly. That may have been due to dehydration, so I try to keep my fluids up during the exercise phase.

    Looking forward to learning as much as I can about this way of eating.


    1. I’d like to add that this is what I do as well. I fast 7 days a week, eating only between 6-10pm, it’s not constant eating but I will have dinner, then maybe a little dessert and a glass of red wine all within this time frame, then I don’t have anything but black coffee till my next day.

      Every morning I get in an hour of cardio; uphill speed walking or a moderate jog. Then I do some weights all on an empty stomach. I feel wonderful living this way.

      I sleep better, I am mentally more clear and focused and after years of trying to find a eating plan that worked for me I can say I finally feel this is right.

      I’m 34 yrs, 5’3″ mother of 1, and weigh 112lbs…down from 178 3yrs after having my son!

      1. Sorry but this sounds extreme. The reduced eating, the hour of daily cardio etc on an empty stomach EVERY DAY…. and your weight is ok now, you can find a somewhat more moderate lifestyle plan now.

  16. PS… Don’t get dragged in by weight loss anecdotes! Many people will experience weight loss simply because they are NOT eating as much as they used to, because, well, their available eating times are significantly reduced.

    1. Moe, do not downplay practical experience. Anecdotal evidence has its place in these types of issues where sufficient scientific evidence has not yet been completed.

      1. Or you could just try it for yourself and experience the benefits first hand! Placebo or not you’ll look and feel better.

        1. I don’t feel better doing 2 IF days a week (dinner previous day to dinner today), have lost NO weight or body fat whatsoever (in fact, I seem to have put some weight on and body fat seems to have increased!). During fasting, I got some headaches and have low energy issues: not so much physically but rather I feel unable to do any mental work (even invoicing or playing sudoku feels difficult, let alone creative thinking about where to take my business or contacting clients). Also, I am a fitness instructor, so I am expected to be active, energetic and in a good mood (not grumpy from lack of food) daily.

          I do enjoy being able to have a nap in the afternoon between classes, but overall I suspect this approach is best suited to men than women.

  17. Have many of you tried the Master Cleanser by Stanley Burroughs. Its the one done by Beyonce with the Madal Bal Syrup. I am actually the US distributor of the syrup and thought some of you might be interested. The Master Cleanse makes fasting a bit easier than juice fasting because you get more calories from the syrup yet you still give your digestive system a rest. Over the years working with this diet I have heard so many miraculous stories that I really believe periodic fasting is the missing link in western medicine.
    Be well,
    Charlie Rebich

  18. Hi,
    I have been doing intermittent fasting (eating every other day) since January of 2007. I only use water on my days off food. Many people I explain this to say it sounds to difficult for them. However I found the body adapts and gets use to the routine, you have to stick with it or it becomes difficult. That is the only trick to it, just maintain the routine and you won’t be hungry on the days off, but if you cheat and make exceptions your system gets confused and you will have trouble. When people ask why your not eating today, just say you are detoxifying today(which is true), don’t say fasting or they may start to judge you because they may not understand etc. I’m also now a 100% vegetarian with I am enjoying very much and have never felt better in my life. I also completed a long fast (healing) in January for 14 days (water only) this was more difficult and I don’t recommend anyone to do this without a lot of knowledge on it first and even medical advice from a Doctor who knows the subject. I plan on a 30-40 day fast (water only) when I’m ready. The intermittent fasting will always be part of my life and I just would not be happy going back to eating food every day. If you have any questions I checked the notification for resposnes to this post. God Bless!

    1. “I plan on a 30-40 day fast (water only) when I’m ready. ”

      I really hope you’re not serious, because this is a recipe for serious health problems up to and including organ failure, hair loss, severe weight loss, and even death…

      1. Many people complete 30-40 day water fast all the time. However, for the unexperienced faster you would want to be under medical supervison as you have to monitor the body carefully. For the experienced faster you will know already if you can undertake a 30
        -40 day water fast. Also you would want to ‘fast prep’ meaning living a ‘very’ healthty lifestyle for as much time as it takes to be in excellent health – otherwise the toxins released during 30-40 days could cause complications. I’ve completed 5 – 15 day water fast with no supervision and no trouble and will complete a 30 – 40 day water fast when I know I’m ready for the journey.
        There is over 100 years of medical data showing the safety of water fasting.

        1. You posted this in January so you’re probably dead by now, but if you’re still in the process of “prepping”, please don’t starve yourself for 40 days. You will die. You’re a lunatic.

        2. I’ve never starved myself and your generalization that fasting for 40 days causes starvation is incorrect. A complex organism in a true fasting mode has no direct biological relation to the state of starvation…starvation only occurs when all the bodies reserves are depleted and you start converting energy from the vital organs. A person in starvation mode would be hard to miss – skin would be tightly wrapped around all the bones and they would look like they should be dead. I’ve been fasting periodically for many years so my body is well adapted for this lifestyle. Anyone without years of experience should probably not attempt a 40 day water fast but rather stick to 15 days or less under medical supervision.
          Final note: Comparing fasting to starvation has been an error I have seen in some medical books – this is due to lack of knowledge on the subject and also often used as a scare tactic to keep the general masses from discovering the power of fasting. However, I do not see fasting becoming very popular as many people I find ‘live to eat’ instead of eating to live.

        3. i find it interesting how so much of this parallels the eating patters of an anorexic/bulimic.

          i should do, i am both.

        4. According to Bragg, starvation does not occur in a 30-day fast. It is only if you fasted, over 40 days that you would incur starvation. He should know because he did lots of (distilled) water fasts and healed lots of people that way (and lived a long and healthy life). However, I simply cannot accept the highly ketonic state they cause – it makes me feel very sluggish and unwell.

        5. Props to Jordan, who seems to really know what he/she is talking about. I’m curious as to whether you ended up taking on the 30-40 day fast, now that it’s October, 2013?

    2. Hi Jordan,

      What do you find to be the benefits of alternate-day fasting?

  19. Hi I was just wandering around looking for more information on fasting, I myself am on my 8th day of just water, I am feeling so much better, I havent cheated once and I started at 242lbs and now Im at 217lbs, the weight came off quick in the begining and now I loose about 1lbs a day, I am so pleased that I dont feel hungery I never thought I could even go 1 day without food. So to anyone that has doubts( You can do it!)

    1. Hi,

      I have done the master cleanser and lost about 40 pounds, How many days have you gone and how many have you lost. I am now a hardcore grok, so no fear in gaining the weight back after losing it.


  20. IF may be good for your health but not for losing weight. As soon as you eat the next day you start gaining it back at least for me.

    1. One thing about water fasting is that it forces your body to use the energy stored to maintain activity. That’s its only choice, since no energy is entering the system.

      Because of this and the fact that fat is the body’s optimal source of energy, IF is excellent for decreasing BF levels. I certainly suggest that everyone try short fasts at first, as recommended in the comments previous to mine. Maybe 16-20 hours at first. Maybe one day out of the week. Something like that.

      As for you regaining some weight (did you mean fat or just BW?) after you stopped, it could just be water weight OR you were simply eating the wrong food.

      Another thing to keep in mind is that body weight fluctuates to some degree. If you gained weight the day after your fast ended, it could simply be because you had extra weight in you! The food!

      All the best,

    2. Cheryl, I agree. I also think this is more of a problem for women than for men. Men seem to do better on IF diets (also the “5:2 diet”) and similar. Women may need to keep a more balanced food intake (including enough good fat) for hormonal balance, for instance.

  21. well it has now been a little over a month and as I said I started at 242lbs and now Im at 192lbs. I have now started eating a little veggi broth and every other day a mashed up veggi like a carrot, I mash it so it digests faster and easyer, for me this whole thing has had to be a change that will be with me my whole life, you see my grandmother died at 700lbs, my mother is 450lbs and I have a younger brother that at 22 weights about 360lbs so my fasting has been to correct my eating habits and make the change that will keep me around longer for my 3 children, I cryed when my kids got excited that they could give me a hug and fit their little arm’s around me all the way, I feel great inside and out, I will never make excuses again!

    1. I know this was 3 years ago.. but reading this comment made me want to cry (happiness and hope)! I hope you’re still strong!

      1. I’m real inspired at this post. In my 20’s I IF’d after two childbirths and lost about 75 pounds after each child. I kept it off until age 35 when my job and a divorce got too stressful. Then at 40 I was disabled and jumped to 235 pounds with hypothyroidism. I fasted off 35 pounds three years ago. Then got into cycling and lost to 187. Then injured a knee for a year and up to 216. Last week decided to IF like when I was in my 20’s. I mainly fast and only eat a full large meal every 48 hours. I’m on blood pressure meds with a diuretic so on fasting nights I have bullion so I don’t get sick from the blood pressure medicine. I spice it up with jalapeno, fresh basil, chinese 5 spice, onion and it feels like a meal! If my stomach hurts I might have 4 crackers or a cup of soymilk right before bedtime and take calcium, vit D and magnesium. I am on calcium and D per my doctor for deficiency. I do this for 5 days then eat for two days. I just did my first week and went down a size. What I like about IF is freedom to eat foods I like again without guilt. I still eat mostly vegetarian but BBQ or ice cream doesn’t freak me out like it used to on occasion. I am prediabetic so I am hoping to lose 100 or so pounds in a year and reverse the diabetes and high cholesterol and not need blood pressure meds. I have to get my health back. Everyone nearly in my family is diabetic and I don’t want to be one. I’ve tried every diet in the world and IF is the only thing that works for me. I believed the media on low fat etc and I ended up fat again listening to the media and the government/ food industry hype. Never again! I IF’d from age 18 to 30 doing it two days a week for maintenance. I was in perfect health and slim. I **will** do it again. Also to Mary Titus. Watch the fats. The liver will turn it to glycogen and it becomes sugar in the blood on your morning fasting glucose meter. Fat is ok small amounts.The liver turns any food group into sugar as needed. Carbs spike glucose right away whereas fat becomes blood glucose 8 hrs later.

        1. Soymilk? I hope you realize soybeans cause so many problems from reproductive organ disorders to hypothyroidism to brain shrinkage that they are basically well-marketed toxins, right?

    2. Wow…that is amazing weight loss!!!! Did you notice having a lot of loose skin after losing so much weight so quickly? I enjoy fasting but never wanted to lose more than 10 lbs at a time so skin can catch up!!

  22. I have being on a 20-hour daily fast since 04-01-07 and the result has being amazing.Prior to this fast ,i was lethargic,having chest pains,weighing 83kg(height 5ft 4inches),depressed.presently i am weighing 65kg which i have maintained for past 6 months.I have never experienced so much energy and happiness in my life.I am focused and rearing to go.I eat as much i like after 6pm daily and stop eating at 10pm.i have not being sick since i started this program.I hope this helps someone

  23. Yeah same here atumu I have been doing 20-hour daily fasts on water for nearly 2 years I dunno if its working but I am about 54kg 5’7. I eat as much as I want anytime really. Sometimes I start at 8pm, sometimes I start at 5 – 5:30pm. But no earlier than 4:30PM. When its cold and rainy and I have got nothin to do in the evening I just start whenever.

  24. One meal every second day would be the best lifestyle for humans-(super). The meal should be of the highest possible nutrition such as oranges and apples and only small amounts eaten over a few hours. If one absolutely feels they need more calories then adding juicing to the meal would work. But remember the trick is to provide only what the body needs nothing more and nothing less. All cells in their natural state are immortal until debris is introduced (caused by eating) which leads to cellular death-(aging). Since humans have no other method of cellular stimulation – (needed to live) besides eating we are stuck with eventual death. To reduce the speed of cellular death we need to eat only what is required for stimulation allowing human life using food types that have built in cellular protective characteristics such as anti-oxidants.

    1. Boy I don’t know about just eating apples and oranges cause you would be a twig literally starving wouldn’t you? If you have NO protein you have NO muscle. Which means you can pump all the iron you want and its not gonna do anything if you can even still lift it. Won’t your body start eating your muscles?? Can’t you do a water fast like two to three days a week then on the other days eat 4 to 6 meals with lots of protein, complex carbs like red and sweet patatoes and veggies?? What do you all think?? Lose fat, still build muscle?

    2. Interesting. Too intense for me, but I do a cleansing fast ever quarter. Stanley Burrough’s Lemonade Clease. I love that for 10 days or more. It renews my resolve to stay healthy. I started at 317 lbs now I am 227 lbs. Not sure of a weight goal, just a how I feel and look goal. These stories though encourage me. I commend anyone who sticks to what they believe in.

      1. Actually Master Cleanse. It’s a whole lifestyle change. Eating veg. after a 10-60 day cleanse. Small amounts of fish organic only. I don’t striclty adhere, but I do get as much organic food as possible. I still do pork and beef a few of times a year.

    3. Correct, absolutely correct. Young
      children and adolescents need at least
      3 meals a day. Young adults to age 30
      probably only two. From age 30 or 35
      to age about 50 one meal a day is
      ideal and beyond age 50 only
      one meal every two days. I currently eat
      only once every two days. The single meal should include all food groups and, (unless you are trying to lose weight), enough
      calories to keep the weight stable. Absolutely the worse diet you can have
      is ‘grazing’; this overworks the Beta
      cells in the pancreas (these produce insulin) and continuous eating is the major cause of the rise in maturity onset diabetes and obesity in our
      society. The human body has evolved to
      not only tolerate episodes of fasting
      but this is the NORMAL metabolic state.
      During fasting insulin drops and the
      pancreas releases glucagon. Glucagon
      raises the blood sugar and tells the heart to stop burning sugar and start burning fat; the heart is an obligate
      fat burning organ but only burns fat
      when the glucagon is switched on
      (i.e., only during fasting). The heart is the only obligate fat burning organ in the body. Dominance of glucagon metabolism over insulin (in terms of time) slows down the aging process, raises the good lipoproteins and slows down the rate of vascular atheroma development. Hence it lowers the risk of
      stroke and heart attacks (smoking is a much bigger risk factor however; so stop smoking before you even think about doing any fasting). It also reduces the blood pressure. It takes getting used to but, believe me,
      it’s actually easy once you become accustomed to eating every second day
      only. (N.B. I regularly swim 3 kilometers before I eat my meal, having
      not eaten for at least 36 hours – no problem at all).
      Hope this helps people.

      1. greg, I love your type of knowledge, can you recomend books, or sources where an exposition of your thoughts can be found?

  25. Why does everyone choose to do an eating window
    at night? I much prefer to do breakfast thru
    lunch and then fast for the rest of the day.
    It just makes more sense to me. I have only been
    trying it a few weeks just to loose some additional fat to increase my running speed. In the past the easiest way to loose weight was to
    concentrate on limiting my evening meals. It also
    frees up more time for you to do other things…
    like the exercise of your choice.

    1. I prefer the evening window because it allows me to have dinner with my family. I struggle with not eating in the evening when I have to cook and the rest of the family gets to sit down and enjoy it. I’d rather not eat while I am at work. I use my breaks to read my favorite books or magazines instead of eating then enjoy dinner with the ones I love. 🙂

    2. Not everyone is the same. What works for you may not be ideal for others. For some people it may be easier to sleep through the first 6 to 8 hours of their fast. what better time to be hungry than when you’re asleep?

    3. I do so in the evening simply because I’m not hungry in the morning. I’m at 84 kilograms, by the way. My healthy weight range is from 60 to 80, so I’m aiming for the happy medium of 70. Last Sunday, I started doubting the often repeated advice that breakfast was necessary for weight loss, and I stopped eating breakfast, starting my day with just water. At my age, 43, I don’t think I even need lunch. The usual mantra is that you’ll eat an entire warehouse full of food in the six hours a day that you’re not fasting. Ha! I’m eating the same amount at every meal as I normally do.

  26. I like your concepts, Jordan. You would become
    really lean and effecient on that type of diet.
    Getting going on it would be an adjustment though…

  27. Regarding the eating window. My theory behind eating a super only instead of breakfast or lunch is this: Digestion takes allot of nerve energy, if you eat breakfast and lunch the body is busy assimilating food all day. If you avoid eating breakfast and lunch, you instead detoxify all day (repairing) and you have all that extra nerve energy to use on what-ever you want…work etc. Some of the Free E-Books on my website discuss the NO breakfast approach to health.

    1. I love my breakfast… I feel hungry in the morning (within 1 hour of being awake) and it is hard not to eat then. If I don’t eat (ignore tummy noises) because of time-pressure or as an experiment, I then start feeling weak by lunchtime and weak/grumpy/hating life by 2pm. My diet is fresh foods, mostly veggies, some fish, fruit and nuts/seeds, no dairy, no grains.

  28. Jordan,

    Now I understand…you mean supper instead of
    super, right? I thought at first you were saying
    that eating once every other day would make you
    a super human.

  29. Mark,

    I think you might have to do a more clarifying post. I don’t think IF is meant to be long periods of starvation, and it seems some of the people responding think that is what you mean. People SHOULD eat, but there are benefits to intermittently not eating. I’d love to hear more about what are acceptable intervals and what is just plain starvation.

  30. First I should mention that fasting and starvation are two different things completely. During fasting the body uses Ketones for energy built primarily from fat reserves. During this time the body cleans house…removes any debris and attempts to rebuild any damages that it finds. Starvation only starts after all possible Fat and lastly muscle reserves have been depleted-basically you would look like a walking skeleton with some skin on it before you begin to starve. This takes many months to start for the average size human.

    Starvation with an IF lifestyle is impossible in my opinion. IF generally includes eating one day and fasting the other. I practice this lifestyle. I take in vegetables and fruits in liquid form every second day – no solids. I then Dry Fast (no water – no food) the other day for about 36 hours. (Dry fasting only recommend for experienced fasters) In total I go for over half the year without food or water, additionally I do at least two 15 Day water fasts. I maintain a weight of 190 pounds and I am very physically active. If fasting every 2nd day is too difficult then even 1 day a week would be very beneficial to the body and mind. For anyone truly serious about adopting a lifestyle involving fasting then you may wish to visit This site has fasting MD’s who are very experienced with supervising fasting. It was a great help to me when I was just starting a transition to this lifestyle. Remember… we are not nourished by the amount of food we consume but rather by the amount we assimilate.

  31. I can offer a comment to G’s question about why some of us choose the evening as the eating window. I used eat only during the day but it often proved challenging to refrain from eating at night if hubby was cooking something that smelled fantastic. Not to mention air popped popcorn (one of my weaknesses). As a result I was sure I consumed more calories than I was aiming for.

    Since reading this website and trying the reverse – black coffee between 9 and 10, water with lemon all day and breaking my fast with fruit, then easing into a big salad, protein and steamed veggies at night. I have had postive results overall.

    In addition, eating at night will allow me to fulfill all my social engagements without having to be so fearful of eating. I am definitely less food obsessed and look forward to eating rather than having it be all about weighing my food and trying to figure out how many calories etc.

    I use the 3 days on, 1 day off schedule promoted over at and do a run with some intervals followed by a cf workout.

    Thanks so much for this website, Mark!

  32. I have really enjoyed reading all of these very informative posts. I found my way to IF through a diet called The Doctor Johnson’s Up Day Down Day Diet. He suggests eating no more than 500 cals one day, then eat to satisfaction the next. But he had also talked about intermittent fasting, but said that “most” people could not do that, so their goal was to stay under 500 cals. But being the hard headed person I am, I was determined to not be “most” people. I have been fasting every other day for 2 weeks now, and find my fasting days much more pleasurable, than my eating days. I have more energy, better mood, and all around improved perspective on eating, and my relationship with food. I enjoy my ability to eat more intuitively now. I will be following this way of eating the remainder of my life!

    1. This page hasn’t been active for a while, it seems, but still a wealth of information and sharing. After an accident resulting in severe hip injury, I was extra-motivated to lose weight. At 40, I was about 75 pounds over. Factors such as difficulty exercising due to pain and reduced mobility, plus a change in my living situation, led me to what seemed an easy and natural solution: I just stopped eating alone. Sometimes I would eat one or two meals every day, sometimes I would go up to 4 or 5 days fasting. When I do eat, I eat whatever I want. And this ”whatever” has changed, as now I only want to eat healthy foods. I have done up to 15 days water fasting in the past, and find it easy. I’ve lost over 50 pounds in the past 7 months. During periods when I eat ”normally”, I don’t gain weight, but maintain. This is working for me. It’s easy, both physically and psychologically. For most of human history, eating has been a collective activity.

  33. Excellent Jackie! With strong will power and our advancing knowledge one can achieve a level of health that is un-heard of ever. I hope to be dry fasting 3 days and one day eating within this next month. Right now I’m still only 1 day on one off. Definitely I too fell much better on my fasting days. Good luck and stay strong!

  34. I’m interested in starting this diet. Help me out! What does the one day on and one day off consist of? Do I eat anything I want the first day, then on the next day just drink water? HELP!

  35. From some experiments that I have read from the National Library of Medicine it seems you can eat as much as you want on your eating day and still get the health – life extension benefits of fasting. The benefits are much more powerful then caloric restriction and you don’t have to get so skinny. The eating every other day such as 1 day on – one day off extends life generally about 30 – 40 percent an average suggest many experiments. The longer in between eating the longer the life extension. Reason seems to be (my theory) that the huge energy draining process of digestive metabolism and natural toxic properties of food cause what we like to call aging. Think about this: Even Fruits don’t want to die (be eaten) so they have a substance call fructose which is poison for mammals; luckily the fruit has anti-oxidants to protect itself from the poison fructose which also may protect us from the fructose to some degree. The simple method for eating every other day is not counting the hours but simple by sleeps. So Monday you Fast then go to bed and Tuesday morning you can eat all day if you want; then Wednesday Fast again etc. After you do it for a while to get use to it. But if you cheat you have to get use to it all over again. The body seems to get into a rhythm of eating and fasting which actually helps to make it easier. If your new to fasting you can use water on your fasting days; when you get lots of experience you can do dry Fasting (no water) the body obtains water from fat cells and other means but with that you need to know your body well (listen to your body). Dry fasting gives your body total rest from processing external substances forced into it hence making it a bit more powerful then water fasting, but it’s only for experienced fasters. If you want support from the fasting community including an experienced Medical Doctor who supervises Fasting check out I have a hundred or so forum posts on that site.

    Good luck,
    Jordan O’Hara
    Cure Zone Ltd.

    1. “Even Fruits don’t want to die (be eaten) so they have a substance call fructose which is poison for mammals”

      This is absurd- the purpose of fruit is to convince animals to eat it, therefore spreading it’s seeds. Fructose attracts mammals VERY strongly, which is why fruits contain it.

      1. Fructose seems to serve both purposes, but let’s not be fooled: it is a metabolic poison in any significant quantity.

      2. According to Michael Pollan, fruit are used by plants to attract eaters (humans, bears, etc.) so that seeds will be distributed and more plants will be produced. Plants bribe us to spread their seed; they don’t know that these days humans usually put seeds and pits in garbage bags.

    2. If fructose was made to poison humans it wouldn’t be a leptin-disruptor as well, since that would incourage us to eat even more fruits. More likely, fructose in wild fruits was only found in small amounts and while your liver doesn’t like it much it would have been better tolerated than in today’s selectively bred fruits.

  36. I have been following an IF diet for about 2 weeks now and i feel great. on the days i go to work and school I fast for 20 hours and eat around 1500 to 1800 kcal in a 4 hour window. I feel completely free from having to plan my day around my meals I now plan my meals around my day. On days i don’t have school or work(the weekend) i follow a paleo grazing diet with one “cheat” meal. The results are amazing, my wieght has gone done and my strength has gone up. I also have no early mourning slump i believe due to my old “larger” breakfast.

  37. Jordan, your last comment belies a fundamental misunderstanding of biology –

    “Even Fruits don’t want to die (be eaten) so they have a substance call fructose which is poison for mammals; luckily the fruit has anti-oxidants to protect itself from the poison fructose which also may protect us from the fructose to some degree.”

    This is ENTIRELY false. Many plants rely on their fruit being eaten by animals to disperse their seeds – the animals eat the fruit and then crap the seeds somewhere far away, where the seeds never would have gotten if it weren’t for the animals. Many seedlings that just fall to the ground beneath the plant may not thrive due to shade from the mother plant. Also, why do you think most fruits are so colorful? You’d think if they didn’t want to be eaten by animals, they’d camouflage themselves in green. They’re colorful to attract the eye of roaming animals.

  38. This is not Entirely false. We’re talking chemical warfare and plants are damn good at it. We only eat the failures. Otherwise they do their best to kill us. Why should it be any other way?

    We seem to be in the midst of an “evolutionary arms race”, meaning plants evolve to make us carry their seeds and/or to fend off being gobbled by poisoning us, and we in turn evolve to process those very toxins, or at least to somehow neutralize them. However at this point we are still greatly damaged by fruit toxins – i.e. fructose. Fructose triggers deleterious modification in cells through the glycation process.

    It’s all too easy to pick a nice shiny red piece of fruit. Too easy, I would say…

    Plant defenses can be classified generally as induced or constitutive. Constitutive defenses are always present in the plant species, while induced defenses are synthesized or mobilized to the site where a plant is injured. There are wide variations in the composition and concentration of constitutive defenses and these range from mechanical defenses to digestibility reducers and toxins. Most external mechanical defenses and large quantitative defenses are constitutive, as they require large amounts of resources to produce and difficult to mobilize.

    Induced defenses include secondary metabolic products, as well as morphological and physiological changes. An advantage of inducible, rather than constitutive defenses, is that increased variability increases the effectiveness of the defenses.[11] This advantage comes from the suggestion that if herbivores can choose among different plants and plant tissues, they may avoid eating plants that have both constitutive and induced defenses.

    Plants have developed many secondary metabolites involved in plant defense, which are collectively known as antiherbivory compounds and can be classified into three sub-groups: nitrogen compounds (including alkaloids, cyanogenic glycosides and glucosinolates), terpenoids, and phenolics.

    Jordan O’Hara
    Cure Zone Ltd.

    1. If a plant kills the animals which spread it’s seeds- it will die to. Fruiting plants have a symbiotic relationship with the animals that eat the fruit- not an arms race.

      Fructose will not kill or harm mammals in the levels they obtain in the wild. It’s only dangerous when concentrated and making up a large percentage of your diet (like in soft drinks). No wild mammals will get diabetes or insulin intolerance from eating an occasional fruit.

    2. This is a major part of the reason why I prefer to eat as fewer plants as possible, preferably zero.

    3. Do you realize that the bees are responsible for the fruits we eat today?

      The bees simply cross-pollinate the pollens onto another flowers, fruit trees etc.

      What makes the bees want to cross-pollinate?… Fructose!

  39. I like it simply because I am not FULL all the time. I get bloating pretty easily, and doing this is simple, I get to enjoy good foods and not worry about eating so much AND I feel lighter and only full once a day or every other day.

  40. Hi Mark,

    I learned about IF after reading a few entries on this subject on Dr. Mike Eades blog. I found it intriguing considering the fact that I had begun gaining a lot of weight on my low carb diet. Atkins is a diet that is perfect for me and I didn’t want to give up eating that way even though I had gained all of the weight that I lost and then some. I now fast for 20 hours and eat within a 4 hour window. I also increased my fat intake. The results have been great. My weight is slowly dropping and people are commenting on my weightloss.I wore my size 8 dress on Friday and it fit perfectly. Losing weight without changing the diet, so to speak, is the best part of IF. Eating a higher amount of fats have also been rewarding.I have included coconut oil and pure mct in my diet alsong with magnesium and vitamin D3. I am hypoglycemic ( self diagnosed )and have had no crazy episodes of insulin spikes.I function well during fasting. I do not experience dizziness. Once I had a headache which I blamed on my fasting but recall reading in the Brain Trust Program that headaches may be cause by low magnesium. So instead of ending my fast earlier than planned, I took one of my mag supplements and the pain went away just like I had taken an aspirin.Before I began Atkins, I had some severe joint pain. I felt elderly at the age of 45. But soon after beginning Atkins that pain dissipated considerably. However,I had some residual inflammation in my joints which vanished completely once I included IF. I am sure this is due to the anti-inflammatory properties or IF,LC and coconut oil.I really want to stand up for IF because it works and it is healthy.

    I have included IF to my diet for 1 1/2 years now and I have lost nearly all the weight that I regained and I hope to reach 135 lbs in 2009.


  41. I’d like to add that the reason that I had the guts to IF was that Drs Eades tried it…they didn’t look for human guinea pigs to do it. They did it themselves. I knew that with my healthy low carb wisdom, I too could embark on doing this. And I must say, I have been more sucessful on it than the doctors cuz I stuck to it.

    Mary again,

  42. Will it disrupt the desired benefits of fasting if one takes a fish oil or multivitamin supplement? The same goes with a simple cup of green tea.

    Will these throw off all the benefits?

  43. Yes, it will disrupt the fasting ‘detox+repair’ mode of the body & you will not have near all the benefits of water fasting. You should only have distilled water.

  44. I have been IFing since Jan 1st, so it’s been 2 weeks. I started at 125 and I haven’t lost any weight yet! I have been fasting all day and eating between 2 and 6pm. I also would out 40 minutes 5 days a week! When should the weight start comming off???

  45. Two weeks? How long did it take to prep for IF? It took at least a month for me to achieve the ability to IF. I don’t really know when the weight began coming off. I can testify, however, that it did come off. I did not starve my body and I gave it the time it needed to adjust to the new feeding schedule.At least that was my determination. I didn’t want to begin anything that I couldn’t continue, indefinitely.Kelly, you cannot begin IF, make it a temporary change and expect it to be a weightloss bullet.When you learned to drive a car, did you drive 85 miles an hour? I would assume the anser is “no”. Don’t expect IF to be any different. If you plan to do IF, you should also plan to do it as a lifetime change. Go slowly. Kelly, I lost 25(ish) lbs. in less than 2 years. I didn’t drop 25 lbs in weeks or months. As a matter of fact there were moments when my weight increased. However, my periods were lighter and shorter.Residual joint pain vanished. I felt lighter even when I had an increase in weight probably because of my increased regularity.

    I made IF my friend. As the years go on, I have grown closer to IF. My body is actually responding to exercise and other physical activity. Since nothing was guaranteed, especially weightloss, I didn’t doubt the success. I receive way more than I expected. All I had to do was wait for it to happen.

    Jon, I drink coffee with cream and MCT oil in the morning. Vitamin D, krill oil and a b vomplex tablet is also consumed in the morning. No, it does not disrupt the benefits of IF.

  46. I’ve been doing a couple of 36 hour fasts a week since last April. My experience has been that I do better with both energy and losing weight if I really, really keep up my vitamin intake. While I know it’s not “pure” fasting, I do drink a single zip fizz (10 calories) for vitamins on my fast days, and make a point of getting enough water. I have the completely unscientific impression that a body not getting enough vitamins will be more reluctant to let go of it’s energy resources, like fat!

    I also drink caffeinated tea with artificial sweetener on fast days. My energy levels, mental and physical were just too low when I water fasted. I’ve lost 30 pounds – and considering my really spotty compliance, that’s a great result!

    The way I see it, the eating plan that works for you is the one you can stand to stay on. Obviously, the jury’s still out on whether this does anything to extend my life span, but my only ancestor who I know fasted (one day per week), was also the longest lived.

    1. That’s fantastic how far you’ve come. I have been experimenting with weekly fasts for a month now and have started testing bi-weekly 36 hour ones. I tend to overeat afterward but am learning to manage.

      I’m curious what you did to prevent a binge if you ever had the inclination.

      Thanks; and I especially liked reading the longevity portion (my theory as well).

  47. Kelly,

    IF is a very slow way to lose. It took about 1 year and 8 months to lose 25 ish lbs. It took a few months to lose 5 lbs and it didn’t happen all at once. I did the fasting, taking my eyes off the scale. I began losing 2 lbs here, 5 lbs there until I began getting comments on my weightloss. The onlything I did was implement IF to my low carb diet.

  48. Please keep in mind that caffeine and fasting might not be a preferred mix. The drug Caffeine promotes physiological aging. The fasting organism is trying to repair / detoxify and stop aging damage as quick as it can – so by adding the caffeine drug you may be negatively affecting the health recovery potential of your fast. Additionally the body is not in a true ‘fasting state’ until ‘all’ food / drug is stopped from entering the digestive processes.

  49. I’m aware that it’s not a “perfect” fast, but it’s what I can do, and I think it’s definitely less stressful than trying a more traditional diet. I’ve gone off caffeine long and short term numerous times, and find that I really just like it, and like the alertness. And since my primary goal (for now) is weight loss, I’m satisfied that it’s working out.

    I pretty much do just two cups of tea per day, and the aforementioned zip fizz for vitamins. This generally doesn’t provoke the *ahem* lower digestive system response that I get when I break the fast with a 70 calorie V-8.

    But here’s something I was pondering last night: We all absorb a certain amount of *stuff* via our skin. Do you think that soaps, lotions, shampoos and hair gels, makeup, etc. also interfere with your recovery potential? I also know people who are very concerned about the amount of chlorine they absorb by showering in chlorinated water.

  50. Jordan I disagree. If you feel like your body is fasting, you are in a fasting state. I am not fasting like a scientist who has done studies on a few subjects. I am fasting like a human who is on a food restricted diet.I consider my fast broken when I eat my first meal of the day. Also there have been studies made that say that caffeine is indeed healthy. If I had to remove all drugs from my body, that would mean that I couldn’t take medecine while fasting.

    Sharon, we do absorb things through shampoos and soaps. I try to not obsess too much about that. I can’t afford the wonderful cosmetics at Mother’s Market but I do try and buy some things. I do use coconut oil on my skin and I injest it as well.

    This is just my opinion but I get my opinion from things that I have observed.

  51. A lot of changes happen when the body’s energy source is changed. From what I have learned is that the body will not make the ‘physiological switch over’ into a fasting state until all food intake to the stomach has stopped. Many processes then startup such as fatty acids are turned into Ketones, glucose is then no longer the only energy source used by the brain etc. Among the global Fasting community Eating small amounts of food is generally called Under-eating – which can also have many positive effects on life but I wouldn’t call under-eating fasting as that confuses the terminology of things. For example an animal in the wild would not be considered fasting when it is eating small amounts of food.
    Hope this helps.

    As for trans dermal absorption of substances: Yes many small substances absorb into the skin and into the blood via skin including the substances in your water – depending where you live could be chlorine + chlorine bi-products and maybe fluoride too. The lungs also absorb even more stuff & larger stuff but that’s another story. Hope this helps!

    Jordan O’Hara

  52. hey…im use to fasting because im a muslim as ramadan involves fasting without water everyday, these fasts last about 12-16 hours and then food can be eat, what i was thinking of doing was fasting 24 hours a day, and eat at night everyday, is this a good way to do it or not? seein as i will be living off one meal a day at night, roughly a few hours before bed, exercise during the day to lose weight, i will be doing HIIT cardio and strength training, would this work?

  53. I have some days where I eat only one meal at supper time. I am sure that the body can adapt to this on a regular basis.

  54. ohh was it lol…my bad didnt notice, umm yeah that sounds good, but what else can i try? once a day eating only, around the evning time

  55. Hassan, check out “The Warrior Diet” and “Fast 5”. The Warrior Diet is about under-eating during the day and then over-eating during a 4 hour window, preferably at the end of one’s day. Fast 5 is about fasting during the day and eating anything you choose during a 5 hour window.
    Each is a form of IF that has many adherents.

  56. to jordan o hara,hello i wanted to say i liked reading your post about how you have a eating window of breakfast until noon.and then you fast until the rest of the day until the next day. Thats what i do also ive been informed that my eating early in the day is considered IF and for many years id been doing this and didnt know that there was name for this.Im about 5″2 and currently 115lbs and i use IF to keep the 15 pounds at bay and if i keep it clean i wont gain weight . But i still dont understand why night time eating is preferred? if i eat at night in the past i would gain weight very easily and i have a small frame, so eating 2000 calories doesnt work for me even if im supposed to spread it out over a window of 5 hours. I only eat once it works for me i lost 50lbs 6 years ago doing this one meal a day and i work out during the day also.Sorry for the long post.

  57. Hi everyone.

    Been doing IF (18-19 hour daily fast) since Dec 1 08 and love it. I’ve lost 10 pounds with 18 left to go, and I have a defined waist again. This is my WOE for life.

    My stringbean cousin has been IF-ing with a 7-8 hour (no breakfast) daily eating window for about 30 years. A professor suggested this diet when he complained of gaining weight in college. The professor believed that everyone except infants and young children should have an established daily eating window, meals only and no snacking, and his own three kids were 7-9 hour IF’ers by age 25. Athletes and others doing physical work should IF too, but with longer windows.

  58. hi mr.JORDAN
    Im a filipino and just read the articles about IF im just started 24 IF and hope u can give me advised to work on it.

  59. I would start out in small steps – that is to allow your body time to adjust to the new healthy lifestyle of IF. You will in time notice how your body adjusts and IF becomes easier and you eventually require much less food to sustain your physical makeup. You will see that IF provides much freedom. Always try to listen to your body’s biological feed back.
    Jordan O’Hara

    “hi mr.JORDAN
    Im a filipino and just read the articles about IF im just started 24 IF and hope u can give me advised to work on it.”

  60. Actually many who have suffered with neurological incapacities such as epilepsy and Parkinsons disease have been helped tremendously with IF most likesly due to its ketogenic components. In my opinion if IF improves the health of neurons in these people it should benefit those of us without it or prhaps be used as preventative measures for those who are at risk. I have been doing this for 2 years…this week and, although low carb has greatly diminished my migraines, I still had residual auras for some reason. However, after combining a healthy low carb lifestyle with IF, my auras are now gone. This is something to cheer about even if some people might doubt its reliability.

    When it is time to break my fast I eat like a cave woman. I just finished my fast break meal of chicken thighs cooked in collard greens and black soy beans. I had a side of sliced avocado and tomatoes. What kind of mainstream science do you need if you are eating healthy? The best way to determine the health benefits is to try it yourself. You have to do it long enough to notice the results. My first theory upon beginning IF was that it, at least, enabled the gut to complete the digestive process. Afterall, some food can take up to 3 days to completely digest. Soon after beginning IF, I began having a bowel movement soon after my fast breaking meal. I believe that this was something that, at least partially supported my theory. One thing for sure, I feel much better.

    Regardless, I beleive that the neurons need fasting. After much research I know this is a fact even if mainstream science is dragging its feet in the mud.

  61. There is well over 100 years of scientific data behind fasting. Check out the National Library of Medicine for tons of great info. Many Universities are studying fasting right now and have been for many years. The benefits are well know to ‘mainstream science’ however not many people are willing to fast even if it could save there life.
    Jordan O’Hara

  62. I hope it is okay to post this here. It is a blog entry on fasting, ketosis and metabolism. Quite interesting and it is one of my favorite posts. Thanks Dr. Michael Eades.

  63. After i broke my fast is it ok that i ate solid food or ate a lot of rice and fried chicken,meat etc.

  64. Toats, there are 2 concepts on this. How long was your fast? I know that some who have lengthy fasts of 2 or more days experience tummy distress upon breaking a fast with a heavy meal. I rarely fast beyond 24 hours and my meals are according to what I want to eat. I may REALLY want a large meal. If this is the case, I eat a large meal. I do low carb so my meals will have some form of meat/fish/chicken. I also try to eat 1/2 to 1 whole avocado, veggies ( especiallly collard greens, turnips, celery root ). If I have a small appetite, I eat according to that when I break my fast. This may be as small as some homemade chicken salad with a 1/4 of an apple.

  65. you mean theres no problem regarding eating a lot of solid food after 24hr IF as long as u can bear it,ive heard people that skipping meal can cause ulcer can u please enlightened me about this.

  66. sorry i forgot, can i take my vit.calcium (500mg)after i break my fast,i prefer my window at 7 to 12pm started today.

  67. I eat exactly what my body wants at the end of my fasting. Yesterday, for example, I had a baked chicken thigh, 1/2 sliced avocado, and a mix of collard greens and black soy beans ( cooked Southern style ). I add plenty of butter and other fats to my diet. I topped that off with a a serving of sugarfree chocolate pudding. IMHO, the ulcer fear is mythical since it is bacteria that causes an ulcer…not the digestive process. Plus, I try to fast with the mind of a cave woman and she has no clue what an ulcer is. She eats when she can and all that she can cause she has no idea when her next meal might be. All I require of myself is making sure that my food is low carb and healthy.

  68. Oh and about your calcium, I think that it would be just fine to take your calcium or any other supplement right after you break your fast. That is when I take mine.

  69. how come that one of our friend she told me it might harm you due to our small intestine doesnt have anything to grind,about IF or(skipping 2 meal)

  70. Toats, I don’t know why your friend would say that. It makes no sense to me. My gut feels great. In the beginning, there were no grocery stores, no candy bars, no McDonalds, no Pizza Huts. In other words, food was very difficult to come by.There was no way that life could have existed without an extended fasting period. That being said, we all fast. I ate dinner tonight at 7:00 PM. My next meal will not be sooner than 12 hours away. That is, if I eat at 7:00 AM. I don’t even plan on getting up until 9:00 and I may not eat breakfast until 11:00. That would be a minnimum of 16 hours going by without food. My small intestine will be just fine. It takes 3 days for some foods to even digest completely, so I doubt that a reasonable fast would harm any part of the digestive tract. My husband will have surgery on his large intestine and fasting is going to be necessary for a few days. This is to allow the intestine to rest. I had a colonoscopy which required me to basically fast fro several hours. My mom had to fast to heal her pancreas from pancreatitis. If fasting can be used to heal the digestive tract of those who are ill. I am sure it won’t hurt someone who is healthy. I think that the digestive tract does indeed needs rest. After doing this for 2 years, my gut feels much better.

  71. I’ve been doing the fasting now for 3 weeks. Today is the third day. So far I’ve been doing it where I eat dinner the night before and then nothing until dinner today, about 24 hours. I don’t normally make it with NOTHING all day. Last time I ate two cheese sticks and a few pieces of fruit. I would rather not do that, but frankly the low blood sugar, shaking, and feelings of weakness drive me crazy. Is this not normal? I also notice that I have a pretty short fuse on these days. I am über cranky. Does anyone else feel this way?

  72. Jac – most people starting fasting have the same issues you mention to different degrees. However, these side effects do normally completely subside over time. Your body needs to complete a physiological adjustment to the new healthy lifestyle condition. It’s just like quitting a bad habit like smoking. Just takes time to comfortably adjust to the new healthy ways.

  73. In my honest opinion, Jac, you are not eating enough. When I break my fasts, I do it with a butt load of food to make sure that I make through to the next time that I eat. For example, a T bone steak with 3 bean salad and sliced avocado. When I began to IF, I would add a glass of V8 juice. PLUS a nice low carbohydrate dessert such as strawberries with full fat sour cream with a scoop of whey protein . Now, that’s what I call eatin’. I eat like a cave man. My blood glucose remains stable. I am also even tempered. Supplements such as MCT oil,vitamin D3,Krill and B vitamins are also a part of my diet.

    And, like Jordan O. says you do indeed have to allow your body to make necessary adaptations. But, make sure that you are eating enough food. Remember the best part of a fast is the meal that breaks it.

  74. Also, think of the financial savings! That’s why I’m doing IF. We’re basically not eating for six months a year with a one day on/on day off IF. That means no money spent on food for six months!! Imagine the savings $$$!!!

    Also, think of the time saved. Now I don’t have to stop working or whatever in the middle of the day to eat lunch – I just keep on doing whatever I’m doing. I can work later, too, because I don’t have to come in for supper on my non-eating days. IF has major time and financial savings.

  75. Hey Guys

    I did the Lemon Detox with the Madal Bal for 7days. Lost about 6 KG. I could not believe how great I felt. I eat between Midday and 8pm usually and I am thinking of bringing that in between 1pm and 7pm now. The only things I touch outside this Period is Water, Green Tea, Bee Pollen Capsules (High vitamins and minerals) and Fresh Lemon Juice.

    I have never Felt better. I am going to start adding some intencse short workouts in as well between meals in the eating period. GO IF!

    I think it is something that needs to happen more in daily living in the western world.

  76. I’m very new to this but I have a question about IF. What about headaches? If I just skip breakfast I will get a headache by 1:00 if I don’t eat lunch. It’s hard to work with a headache.

  77. If you are new at this, why would you go until 1:00 without eating? That is not the wise way to fast. At least it is not the way I began doing this. If you normally eat breakfast at , say, 8:00 AM. Eat at 9:00 AM for a few days, then eat at 10:00 for a few days. Continue doing this until you work yourself up to your desired oficial time to break your fast. If you experience headaches and have no insulinemia issues, try taking a magnesium pill. Sometimes headaches are caused by low magnesium. I don’t even use Tylenol or aspirin anymore. I take a magnuesium supplement and my headache vanishes just as if I had taken an analgesic. However, I rarely get headaches anymore.

    I do not believe that you should do intermittent fasting without allowing your body time to become accustomed to the change.

  78. I guess I wasn’t very clear with my explanation, sorry. I have not fasted in any way. I meant that I was new to the whole primal way of living. There have been times in my life when for one reason or another I have skipped breakfast, or eaten lightly, and been too busy to grab lunch until late in the day. That is when the headaches start as well as some of the same experiences that Jac expressed he was having.

  79. We all fast. It is just that we are not aware of it. If we didn’t fast there would be no need for break-fast.I posted my concept of IF. That is how I began doing it. I eased into IF until I could go successfully to 3:00 in the afternoon. I have been doing this daily for 2 years. I am also a strong believer in reducing or even eliminating all sugars in the diet. You want to keep your insulin stable so toss the sugar. The best way to make it through a fast is to eat a high protein, ketogenic meal the night before. Also take your supplements at dinner time. You are getting headaches because you are waiting until 1:00 PM to eat. Don’t do that…you are not ready. If you were ready you would not get the headaches. Also if you are not accustomed to eating low carb, that is something else you will have to ease into for what I think would be the best results.But if you want to be able to go through the day without the headaches, you first must address the possibility that you may be experiencing low magnesium. Also address glucose issues. If your insulin/glucose are not stable, that can slam you with a headache. Hence make sure that you consume a hearty protein/moderate fat meal.

  80. Thanks for the advice Mary. It is tough eliminating carbs from my diet espcially since I am a sugar addict. I am trying to ease in to that though, cutting sugar first then going for the breads and pasta. I will keep all this in mind when/if I try fasting.

  81. Yes, it is tough. You must decide what foods you want to be addicted to. Sugar is not healthy. Anything that will rot your teeth as easily as sugar should not be consumed so regularly. Just imagine what it can do to your insides.
    Good luck on your journey.


  82. Hi,, I’ve read about i. f. and it sounds really good. I have one concern though. I am 5’4 and my weight is around 110 pounds. I eat well, and although I am vegetarian, I ocasionally smoke so I want to kick off the habit and try some fastings as well. The most I’ve done water fasting in the past is 2 or 3 days. However, I want to do a cleansing, empower my brain, clean my body. My only concern is how much could I do the fasting if I am mainly skinny, and I have a good metabolism? I guess my point is, how to fast in order to detox my body and my mind, without really losing more weight? What do you recommend? Is I.F. for me? Or should I try a juice fasting instead? Thanks.

  83. I do IF on a daily basis. I do it for its ketogenic characteristics. My body runs better on high octane ketones.This meaning, I eat a normal balanced ketogenic diet in concert with IF.I think that fasting in its own right, cleanses the body without any help especially if you have a healthy metabolism. I am not a vegetarian and cannot really give you any advice that I would feel comfortable with BUT, I do think a juice fast would be counter-productive unless it is done with vegetable juice. Sweeter fruit juices have sugars that will swiftly impact your blood glucose. This would cause your insulin levels to rise and glucose levels to drop, which causes stress to your metabolism. Everyone should strive to keep both glucose and insulin levels under control.

    Keep in mind that the purpose of IF is not to eat less food…it is to eat less often to allow the digestive system to complete the digestive process. By allowing the process to complete itself you will be amazed at how your body will cleanse itself. TMI, I know but this is significant. I have a nice BM that follows within 2 hours after eating my fast-breaking meal. Please note, that I did lose weight but it was only 22 pounds in 2 years. That’s not very fast. If I wanted to do this without weightloss. I eat within a 4 hour periods each day. So between 2:00 and 6:00 is when I eat. I eat whenever I want including snacks and 2 meals, which is my standard rule. The difference with that is, once I break my fast with a large caveman meal, my hunger is much milder througout the day.
    So if I ate according to my standard rule, I am sure that I would not lose…at least not as much.

    I would like to add that doing IF consistantly for 2 years, I have concluded that this isn’t something to do on occasion unless you do it for religious reasons. I believe that it should be done with some type of regularity to maintain healthy metabolism. But, that’s just me. Good Luck,

  84. Plenty of research out there about IF and it’s benefits for the glucose metabolism and it’s neuroprotective stress responses. IF is not CR (Calorie resistriction) yet has many of the same health (and more) benefits. That is pretty amazing in itself. Here’s just one study:

    “A consistent hormonal response to a decrease in food intake in rodents, nonhuman primates, and humans (30, 31) is a reduction in insulin levels and an increase in insulin sensitivity. We found that mice subjected to IF exhibited decreases in serum levels of glucose and insulin to levels at or below those in mice fed daily but with a 40% reduction in caloric intake. The ability of IF to alter fasting levels of insulin and glucose was independent of overall caloric intake.”

    “The findings of this study suggest that IF can enhance health and cellular resistance to disease even if the fasting period is followed by a period of overeating such that overall caloric intake is not decreased.”
    both from study: Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake

    If you improve the state of your glucose metabolism, you will lose fat. IF (even if just 1-2x a week) + Paleo foods will get you lean and healthy…IFOC (IF on Crappy foods) doesn’t work as well….simple as that.

    You can also read about different approaches and 100s of comments about how people are using IF here: >a href=””>Intermittent Fasting 101

  85. Great info Mike OD,

    This is stuff that I read before doing IF. You put it all in a nutshell.


  86. Hi, I have been eating a ‘caveman’ diet for two years, eating 5 meals/day, eating around 100-120g carbs/day.

    I exercise 4x/week using heavy weight compound exercises.

    On those occasions when I have purposely skipped a meal on rest days, I notice a definite reduction in strength in my weights workout the following day.

    May be i’m doing something wrong but I can’t combine IF and weight training without a measurable negative impact on strength.

    I’d really appreciate any thoughts/comments.

  87. From what I understand growth hormone production is stimulated with a combination of factors; Decreased blood glucose levels, increased blood protein levels,carbohydrate-restricted diet, FASTING, increased protein diet, free fatty acid decrease, PGE ( a good eicosanoid ) Stage IV sleep ( circadian sleep ) and exercise.This can be found on p. 191 in Protein Power by Dr. Michael Eades. There is more info on this but I would logically assume that if I have been consuming a lifestyle that is opposite from what I have listed here, it would indeed take some time for the body to adjust to the new lifestyle.Once the adjustment has been made, you should deveope muscles that will have a better sustainimg power.I think that it is worth taking the time to do it. I am not a weight trainer nor am I an athlete but I feel the best that I have ever felt…ever. I plan on running in a 5K race in November. During this race, I will just be finishing up my fast. I will not eat my first meal for anotther hour. By-the-way, I fast everyday.

  88. I have been doing a complete fast with one 24-hour day per month for nearly 30 of my 36 years as part of my religious experience. I can vouch for how it is amazing to refocus the mind: I used to believe that I derived this benefit from all the practice I got from trying so hard to think about things other than food; so nice to know it is from a physiological effect too!

  89. I have been doing a one day a week 24 hr fast for the last 4 weeks. It gets easier every week. I find my strength and cardio workouts don’t suffer.
    Also, during the days when I’m not fasting, I eat about 100 calories every hour. This combo works great for me.

  90. In 2005 I used to follow the Warrior Diet religiously every single day. I was 21 at the time, but was growing a bit thick around the stomach. Fasting works, and it works good. WD makes you eat one large, very large meal a day and I’d normally have a huge salad with tons of protein and fats from evoo and such.

    Every morning I would wake up and do strenuous exercise including kettlebell work and a lot of dive bomber pushups, hand stand pushups, bridges, etc. lots of bodyweight work. Not only did I drop weight but I looked much leaner than I ever had. No dizzy spells or anything.

    Once your body adapts, it’s like any other normal day. I’m doing more Anabolic Diet eating, but cleaner and now I’ll start fasting again once a week. Good article!

  91. IF and Clean low carb food- perfect! Toss in strength training to complete the package. Howl at the moon.

  92. I am wondering whether or not it is okay to fast when breastfeeding. My daughter is 14 months old, but eats little solid food, mostly the breast milk. I am easing into primal eating, and it would be significantly easier with fewer meals. I’ve been told over and over that you’re not supposed to diet when breastfeeding, but I have 100 lbs to lose, and I hope to lose 50 of them at least before I get pregnant again, which is likely when I stop breastfeeding. I feel like I’m in a loop against weight loss by any form except just eating better food and exercising. I know that will help some, but I’ve had trouble being consistent and so I haven’t really lost anything.
    Anyway, back to fasting:
    Would the shorter eating window be okay (Dinner and a snack) If I ate a lot of nutritious foods and a pre-natal vitamin?

    1. Always better to wait until after breastfeeding. I tried dieting during breastfeeding (low fat) and my milk got thinner and my baby a hungry screamer. Remember, on IF you will be dumping toxins into your bloodstream the baby. Also, your baby needs consistent calories and YOUR caloric requirement needs are higher when breastfeeding. I would try the IF but add a teaspoon-tablespoon of coconut oil (lunch and dinner) before eating to keep milk supply steady and healthy and not compromise baby’s growth. Most don’t recommend IF if pregnant or brfeeding. Consult your and baby’s doctor.

  93. I can only offer up my opinion. I breastfed all 3 of my children. If I had it to do all over again, I do believe that I would be better at it the way I eat now. I do advocate eating low carb for the healthiest way to incorporate intermittent fasting. I would also use fats liberally in my diet. Fasting is nothing new…it is just new to modern civilization. Also, IF doesn’t really make you lose weight. It facilitates weightloss by allowing complete digestion.I did quite well losing weight after adding If but all in all, I only lost 15 lbs a year. A total of 30 lbs over a 2 year time frame. However, I was fifty when I began doing this and I know I would have had better weightloss results at an earlier age.

    Make sure that you are consuming plenty of fluids for obvious reasons.The idea with IF isnot to consume fewer calories, just consume fewer meals.Hope ths helps.


  94. I would like to add something else. If you have dinner at 7 PM and not eat breakfast until, say 9 AM the next morning,you’ve spent 14 hours fasting naturally. Not much different from an extended fast.

  95. Thanks, Mary
    I can make that 14 hours just fine. Maybe even up to 16, if I’m inactive. Still pretty blood sugar sensitive. I’ve been easing into this lifestyle, Trying not to be too harsh on my family (my mom complains about how she can’t seem to omit that one last eggyolk, and then turns around and eats boca burgers…) And my husband’s best friends are named Carl (Jr. of course) and Jack, who lives in a box. I’ve gotten my meals to be pretty primal, and even some snacks. Once the stress hits, though, I attack bad food. Ugh.
    Anyways, I figure that if I can keep the discipline of an eating window, perhaps it will be easier to avoid the bad foods of the world.
    Now to kick my kid of her Cheddar Bunny habit…

  96. Hi Sara,

    You have your work cut out for ya, I see. I am sure that our primal sisters had stressful moments. What did they do for that? Anyhoo, I’m enjoying our IF chats.With IF I do tend to eat less of the bad stuff. IF is work and I don’t want to mess that up with a hershey bar ;-0

  97. I have been fasting a total of maybe close to 50 days on and off (mostly 5 hour fast got me prepared for longer fast) some 48 fast diffcult need more mental control) and 24 hour fast simple if you keep it up)

    I have had great discourage from a 1 day standstill i know that was silly (suffer from alot of doubt i swear if food talks to you it does on the inside to)

    and switched back to diet pills for 3 days and horrible thoughts in my head.

    I had wls 7 yrs ago lost over 200 pds i look amazing i must say but i been trying for the last 3 years to get to my (last goal of 120) and i have tried alot of things that i knew wasn’t right..But since i started fasting besides learning a new relationship with myself with out food (which i thought i could never live without and i know if i chew even a piece of gum i have to raid the fridge i have problems with food)

    IF not hard it has been rewarding. Lol i been tip toeing around a 30 day fast i am going to have to work on that. I even thought about keeping up the 48 fast its a bit more diffcult but reguardless fasting has saved my life i think besides the fact i think GOD gives us more than what we need to survive. The health reasons must be way higher than having mcdonalds 4 times a day.

  98. Holy Cow…who the heck want to take 2 years to lose 25 lbs?? Mark, I think your original post got hijacked! Over at, I regularly see people completely transformed from 30% fat to under 10% for contests…in 3-6 months! Now I’m not interested in that lifestyle, and I don’t want to eat 6 flippin times a day, and I think fat is essential… BUT… these comments have done nothing to sell me on IF. I think, if done how you intended, it should have 3 benefits: 1. make you feel good, 2. give you the mental strength to not panic every time you don’t have access to food, and 3. help you lose weight (if you’re trying to do so) or maintain (if you’re already there.)
    Food is not evil!

    1. Agreed! Why anyone would think 25 lbs in two years or whatever sounds good, I got a bridge to sell ya! It takes way less time than that if you are eating less. This thread is also full of one or two people posting over and over. Ugh. Internet pontificators.

  99. I would much rather lose 25 lbs in 2 years than to GAIN 25 lbs in 2 years. I know this as a fact because I did both.
    No food is not evil, that is why a love IF…I get to eat all the food I want as long as it is low carb. I just make sure that I eat within a 4 hour windoq. I think that it is great to be able to eat a poop load of food AND lose weight while doing it. PLUS, after eating a poop load of food, I get to have a nice BM. My stomach is flatter without doing any form of exercise. My blood lipids and blood glucaose are stable. I can be physically active without the worry of passing out. I’m not trying to sell you on IF, I am just sharing my experience.

  100. Mary, I regretted posting that because it does seem like I was referring to your posts, when actually it was other posts that I thought turned things around a bit. Unfortunately, it was the “25 lbs in two years” that stuck with me the most, as that would be awfully frustrating for me. You’re right though, it is much better that you didn’t gain that amount instead…you’ve created a lifestyle/weight you can maintain.

  101. Marie, no worries. I actually lost 30 lbs in 2 years and have 10 more to go before reaching my goal. I post about intermittent fasting because I think that I adapted a pretty ideal manner of which to do it successfully and I just hope to be able to help someone to do this without it being a fad diet.

  102. I fasted from Sunday at 7pm to yesterday (Monday) at 5 pm…definitely a first for me barring the flu 🙂
    It wasn’t too difficult because this sinus infection has me feeling pretty bad; and I didn’t feel “light” or refreshed either because, again, I feel crappy from illness…but, I will do this again because,for me, the biggest reason is my #2 above: overcome that panic that comes in from missing a meal..teaching my body that it’s okay, I’ve got plenty of “stored energy” for use!
    So while I believe humans are designed physically and culturally to eat…to share meals… IF is a nice tool to have.

  103. IF does not remove the culture of eating and sharing meals. That is something else that you have to teach your body. Not only is it okay to skip a meal ( althoough, I do not believe that is possible ) but once you break your fast, meals are even more enjoyable
    and sharing meals are even more rewarding.

  104. very interesting reading – I started Fast 5 two weeks ago now but I don’t do it every day – only Monday through Friday and then I eat normally on Saturday and Sundays (although I do low carb on those days) For me it has been liberating to stop eating so much – I seem to be the kind of person that when I start eating in the morning I can’t stop so to not start until 2pm is much easier – then I eat what I want until 7pm but do try to keep the food healthy – keeping it low carb as much as possible… I feel great…

  105. I just discovered IF via a news article about its popularity recently in the UK. I’ve always wanted to try fasting for a spiritual experiment and to shed these extra 50lbs I’ve been carrying for too long. I also have a panic reflex in not knowing where my next meal will come from and I overeat everyday. Last Fri I was forced to fast having no income lately due to economic situation and came across the news article about IF the same day – coincidence? This was two days ago. Yesterday I ate one meal and today even though I could have eaten, I chose to stay with IF. I know my relationship with food has been dysfunctional for a while and am hopeful this might mend it a good deal. Being comfortable not having access to food can be very useful for stress reduction. Not depending on food / meals for peace of mind is valuable. Cutting my food spending in half can mean more money toward other things. I just sort of panick inside at the thought of not having my ‘daily bread’ so to speak. It’s in the lords prayer for crying out loud. Anyway, I can say I started IF out of financial distress but will continue IF by choice now that I have information that it won’t kill me to refrain from food every other day. I plan on treating myself to the pizza buffets on feeding days though but I have a suspicion that those cravings will diminish as my relationship to food improves over time and my choices become wiser. Now is no time to be judgemental on the feeding days. It’s about reducing my food bills, waistline, and depression/stress all at once. Counting carbs and calories, hours and AM or PM of when to eat, and what to eat on feed days just creates complications and stress for me. I believe in KISS. If today was fast then tomorrow is feed and it will be pizza buffet if that’s what I want. It’s one step better than the buffet every day which has been my routine and any step forward is growth. I think that as my ‘panic’ symptoms decrease over time with IF, so will my subconcious need to binge on unhealthy foods. My stomach is growling but I’m excited at the same time. Thanks for listening.

  106. hey John welcome – I’m doing it differently to you – Fast 5 is fasting everyday except for a 5 hour eating window… I need to eat an evening meal with my family for social reasons so this is what I have chosen – I don’t ever feel the need to pig out though – I eat muesli at 2pm when I break my fast – I have a snack with my son after school at 4pm (cruskits with salmon or a boiled egg or even just vegemite) and dinner with the fam at 6pm – normal meat and three veg type meal – I try to low carb but if I feel like a potato I will have it – try to stay away from white rice and white pasta though… empty calories… so even though I don’t count calories I’m aware of which foods provide me with more nutrition…

    it’s great – I’ve lost three kilos in the last five weeks… and still going down…

    just some ideas for you…

  107. Hey there,
    I thought in order to make sure we do not lose any muscle mass during a fast, we had to be in ketosis first? Has that changed?

  108. Ensure you are exercising your muscles during a fast to avoid them being used as food. The exercise will trigger Ketosis very quickly when fasting. I’ve actually gained a couple pounds during 14 day water fasts as I was exercising daily – muscle weighs more then fat. The more often you fast the better this physiological process works. Ketosis activates a critical process called ‘Gluconeogenesis’. If you don’t exercise while fasting your body will absolutely start to each some muscle.

    1. There’s no possible way you gained weight by fasting. The body cannot create matter. Basic law of physics.

  109. Interesting reading all these posts. I am mainly experimenting with an Eat Stop Eat style of IF – that is, for example, you eat at lunchtime, then nothing till lunchtime the next day, and repeat this once or twice a week. By the way – this is a true 24-hour fast — the original post here refers to someone eating on a Monday night and then nothing until the Wednesday morning — that is actually a 36-hour fast.

  110. Hi Oliver, you are only actually missing two meals – sounds very do-able… nice one… I would do that but it’s important to my husband that I eat with him in the evening… so “Fast 5” works well for me… we’ve been away on a two week holiday where we were less than careful about what we were eating and I was very surprised to weigh myself on my return and find that I had not put on weight… my main tactic while away was to low carb and keep portion sizes down… it worked… now I’m back though I will “Fast 5” in earnest… tomorrow will be my first day after the two week break – wish me luck…

  111. Fasting is ketogenic. The purpose of ketosis primarily is to keep the body from consuming itself. Which is why I beleive that it is even more importatn to go low carb when doing IF.I am low carb and do IF on a daily basis 20/4. Sometimes I eat once a day. I would wager that hunter gathererers went much longer between meals than just 24 hours. They had to hunt plus they had no access to refrigerators, Mickie Dees or the A&P. They truly roughed it so I would suspect that they did not eat on a daily basis.

  112. I tend to wait til 1-2PM to start eating and stop at 6-7PM daily. And I eat lower carb usually and if carbs are involved I eat brown rice, potatoes, whole grain stuff. I used to eat 5-6 small meals a day blah blah blah. I have GREAT results so far with this. I workout 3-4 days a week plus run 2-3 days too. Drink as much water as I can and yeah I look the best that I ever have, and my muscles are getting bigger too:)

  113. Mary, I was pleased to see someone doing something similar – yours is a Fast 4 – I prefer the eating window to the simply eating once a day – it lets me eat something earlier than just waiting for dinner – and it works for me – I’ve lost three kilos doing this over the last couple of months and I’m now at my goal weight…

    Jeff – your post pleased me greatly as it seem almost exactly what I do except you exercise more than I do – I have limited opportunities to work out – my son has a two hour tutoring session three times a week and I go to the gym… I probably could drink more water so I will try to take a leaf out of your book – I do drink copious cups of green tea during my fasting hours…

    thanks Mary and Jeff for your input…

  114. Wyngem, I also throw in a 2-3 days a week where I eat just once in a 24 hour period. That really keeps things under control. But, when I eat oncw within 24 hours I prefer to eat ealier than the regular supper time. So I do this on the nights that I come home late. That way, I can eat at 4:00 without having to eat when I get home because supper time is over. Now that I won’t be having rehearsals in the evenings fr a few weeks, I’m gonna have to develop another strategy. But Saturday has been working out well as a one meal a day, So I can at least count on that

  115. Using intermittent fasting, I lost 25 lbs of fat and 7 inches off my waist in 6 months.

    Specifically, on June 14, 2009, I weighed 186 lbs, had a 42.75 inch waist, and 27% bodyfat. On Dec 4, 2009, I weighed 159.5 lbs, had a 35.5″ waist, and 17% bodyfat.

    I started off with alternate-day fasting, but eventually the weight loss slowed down. I realized that it was easy for me to eat too much on my feast days with things like ice cream and quesadillas. I dislike counting calories, so I switched to eating just one meal every day. If my progress continues at this rate, I’ll be at 8% bodyfat sometime around June of next year, which is pretty exciting.

    I have a desk job and live a sedentary lifestyle, except for my every-other-day exercise routine which consists of about 11 pull-ups/chin-ups (I used to do them with assistance, now they are unassisted), 150 or so squats, and 50 or so push-ups.

    In June, I could do no pull-ups. Now I can do 2 chest-to-bar pull-ups (with no break in between) and 3 chest-to-bar chin-ups.

    I’m a 35 y.o. male, 5’8.5″ tall (yes, that half inch is important to me!) I measure my bodyfat & weight with Tanita scale, and my waist at the navel with a flexible tape measure.

    1. Khevlar, this is such an inspiring story for me! I’m currently at 27% body fat myself, and desperately want to bring it down. I definitely want to give this 1-meal-per-day routine a try. I’ve done the Warrior diet previously, and grazed on fruits all day but it never had a significant impact on my BF% or weight. Perhaps omitting the light eating will make the big difference.

      Is it ok to drink coffee, tea, & diet sodas while fasting?

  116. Oh, and for my one meal per day, I have whatever the hell I feel like, which so far means I consume mostly burgers, fries, root beer floats, quesadillas, chips, lemonade, pizza, coke, fried dough, all kinds of chinese& indian food, ice cream cookie sandwiches, candy bars, etc. One of the things I liked about IF was never having to give up foods that I enjoyed. Also, eating for me is a social activity, so I didn’t have to give up having a big meal with friends – I just had to limit myself to once a day, which has actually been pretty easy.

  117. well congrats on the weight loss Khevlar… I can’t say I’m down with your food choices but hey, if you are losing weight and you are happy – it’s good for you…

    good on ya for your exercise achievements as well… well done…

  118. Hey Mary T – I like your style – I wish I could do the once a day meal occasionally but I’m not there yet…

  119. Mary T – what kinds of foods do you eat? you said you were low carbing…
    I have started vegetable juicing to add nutrition and I’m loving it… the cabbage juice is a bit hard to swallow though but it’s supposed to be so good…

  120. I keep my diet as ketogenic and as healthy as I can …which is the way I like to eat anyway. Protein is primary on my diet. I eat lotsa beef, chicken and fish, organ meats. I prefer the fattier cuts and if it is lean< I make sure that I add some butter. I eat a huge variety of vegetables such as collard greens, asparagus, brocolli,turnip greens,green beans, yellow squash, jicama. But I rarely eat more than 2 servings of vegetables a day. The fruits on my list include avocado,bell peppers, raspberries, blackberries, cantalopes, tomatoes…things that are low glycemic yet extremely nutritious. I also keep coconut oil and MCT oil in my diet.I snack on cheese, pepproni ( rarely ) nuts. Now, that being said…I rarely snack.

    The days where I will eat once a day, my one meal is like a feast. I may have steak with a side of salad ( sliced avocado,onion,tomato and cooked shrimp ) and turnips for example.I eat until I am full.

    I also include vegetable juices when I am in the mood for them.In my honest opinion, nothing beats this diet.;-)

  121. Wow – thanks for the feedback Mary – your food choices look really good…

  122. I just googled ketogenic diet – thanks for enlightening me – I’d never heard of it before – it led me to a very interesting article on the Inuit people – I may just re-evaluate my own eating philosophies – still researching… thanks Mary…

  123. What you say seems to make sense, and I would like to try it. Except, here’s the problem: my body seems to absolutely detest the idea of fasting. The longest I’ve ever gone without food was about 6-8 hours. Past that mark (but usually earlier) my body starts to physically go apesh*t if I don’t give it food. I get either a monstrous headache, or serious jitters (I’m talking can’t hold a pen jitters), or I get so lightheaded that I have to drop what I’m doing and sit down or I’ll fall down. Sometimes I get all of it at once. I can’t think, I can’t concentrate, and I can’t function AT ALL. Until I eat. This happens even when I make sure to eat a high-protein, low-carb meal such as steak and egg-veggie omelette, or chicken breast and a side of vegetables (usually broccoli, cauliflower, tomatoes, cucumbers, carrots, cabbage, eggplant, zucchini, peppers). What gives?

  124. I’m no expert Maria but from the research I’ve been doing it sounds like carbohydrate withdrawal symptoms or blood sugar issues… you can work through it…

  125. Wyngem is most likely correct. Imagine eating a high carb diet for years and years and years.Your body has to make adjustments when that diet has changed.I think that it is best to make this attempt when you have the opportunity to stay at home. For one week go for eight hours without a meal…it is much easier than you think. Say you have dinner at 8:00 then do not eat breakfast until 8:00 A.M.the next day-That’s 12 hours there. So be mindful of the fasting hours that occur while sleeping. Then push yourself as far as you can without becoming delerious ;-)If you can go for 6 or 8 hours that will put your next meal at around 2:00 or 4:00 PM. Now here is the hard part, well it is at least hard mentally.Instead of having an omelette have a TBone and 2 eggs and a glass of V8 juice. Add a teaspoon of MCT oil to the juice. Now for me, I find this deeeeliiishous. It is nutritious and it is very filling….you may not want to eat again until supper time.

    Basically what I am saying here is, you can’t jump into it but you can do it if that is what you want do. It takes adjustments. Now as far as headaches are concerned, try taking a tablet or two of magnesium. Headaches are often symptoms of magnesium deficiency

    1. Thanks for the suggestions, Mary! The problem I have with having a big meal in the morning is that I’m simply not that hungry. Sometimes I don’t get hungry until 3-4 hours after I’ve gotten up. Some days I don’t eat breakfast at all and then have a steak-n-eggs or other protein-rich meal for lunch. But you’re probably right, it’s carb withdrawal. I’ve been trying to eliminate non-vegetable carbs little by little, and recently cut out the last one – rice. Hopefully things will get better once my body realizes it’s getting no more of that stuff! 🙂

  126. Maria, I just found this info (in parenthesis below) on magnesuim rich foods – if you have a juicer, try juicing some cabbage or broccoli (with a green apple to make it more palatable) for a headache… only need a small glass – might work…

    “Green vegetables such as spinach are good sources of magnesium because the center of the chlorophyll molecule (which gives green vegetables their color) contains magnesium.” reference

    1. Thanks Wyngem! That’s interesting. I’ll try either the juice or the supplement, see if that works.

  127. Maria, waiting a few hours after waking,in my opinion is even better. That would give you a fast of at least 16 hours. It does not matter when you break your fast. That would get you through until noon. Eat your first meal of the day at noon, then eat your second meal of the day when you get hungry. There are various ways to mix it up. Just find which way works best for you.

    1. Hey Mary,

      Thanks for the tips! I did that today. First meal was around 11 (woke up at 7), and I haven’t eaten since. It’s almost 6, and I’m only slightly hungry, and no bad side effects. Maybe my body has finally gotten over the carb withdrawal. 🙂

  128. good on you for persevering Maria – it does work and it feels great…

  129. Today I had one glorious meal. I broke my fast at 6:30 PM with several slices of pork roast and collard greens and a glass of merlot…absolute bliss.I am topping off the evening with a cuppa joe with some heavy cream.

    1. Thanks for the link, Wynghem! Interesting reading. This is what confuses me: I was told (many times) that if you keep your caloric intake to below 1200, your body goes into starvation mode and hangs on to its fat stores for dear life instead of shedding them. What’s your experience? True or BS?

  130. To tell the truth Maria I don’t count calories at all – I do what is called “Fast Five” i.e. I have a five hour eating window every day fasting for 19 hours each day between 7pm and 2pm – eating betwee 2pm and 7pm – I’m not ready for one meal a day yet although I’d like to get to that stage eventually… Eating for me is quite social so at 2pm I have breakfast (alone) at 4pm I have a snack with my son after school and at 6pm I eat dinner with my husband and my son…
    The kind of food I eat is very important to me so I keep it low carb and high nutrient as much as possible – I never binge and detest junk food…
    Having said I do this each day – I actually only do it Monday thru Friday as on the weekends my husband and son are home and I eat with them at regular eating times – but maintaining the low carb – high nutrient way of eating as much as I can… the main changes for me that have caused me to lose weight doing this is that I no longer eat any of the white starchy carbs (although I do have small amounts of potato if I want but not every day) I never drink soft drinks and keep alcohol to an absolute minimum. I now do vegetable juicing with the more unpalatable types being sweetened with green apple but only enough to make it good to drink…
    I largely eat till satisfied so counting calories doesn’t come into it…

    I work out at the gym three days a week only as I don’t wish to burn out but each gym visit is an hour and a half – 30 minutes cross trainer, 30 minutes treadmill (walking on a decline) and 30 minutes stretching on the mat… this makes me feel fantastic and I’m sometimes tempted to go an extra day but the rest days are as important as the work out days (for me anyway)

    this is my experience…

    a year ago I was ten kilos overweight – I lost five kilos the traditional way and then I hit a wall – I was looking for something to challenge my body and I found Fast Five by researching the net… I have now lost the other five kilos (which is traditionally the hardest to lose – the last 5) so now I’m at my goal weight and I want to make this new eating part of my lifestyle so I’ve no intention of changing it simply because I’ve arrived… I’m not losing weight now so my body has worked it out – I don’t want to count calories – it’s so boring don’t you think?

    1. I completely agree. Not only is counting calories boring, but it strips life and food of all joy and spontaneity. I just find it confusing – if you eat low-carb and high-protein, chances are you’re also consuming a lot of fat, which means lots of calories, and I haven’t learned how to balance yet. Yesterday, 50% of my calories came from fat and I was freaking out. 🙂

      Our foods and working out ways are pretty similar, only I do like my wine (try to keep it at no more than one glass though) and I do aerobics and intervals/free weights instead of the machines.

      My story is also similar. I lost about 20 lbs 2 years ago, then hit a wall. I’m at a healthy weight now, but I feel I could benefit from losing another 10 lbs or so, and I feel low-carb is the way to go. I’m not a big fan of fasting, though. I’m all for it when it comes naturally (i.e. when I’m not hungry/suffering for hours on end). But I feel that if my body is hungry, I should feed it, and if I don’t, that’s not healthy. So I don’t really want to keep myself constrained by any sort of strict schedule. Anyway… Thanks for sharing, and for the tips! 😀

  131. I also do not count calories. I suspect that regardless of what my caloric level may seem to be, it’s a lot higher because of my fat intake. I add cream and coconut oil to my morning coffee. So even when I am not taking in solid food, I am consuming fat.

    The word “starvation mode’ has left a nasty taste in my mouth. I believe it does exist but not the way the experts would like for us to believe. Ketosis exists a protective measure to maintain the body during famine. When we experience famine, our bodies will begin to produce ketones. THese little soldiers protect the organs, muscles, circulatory system, nerves etc.
    This actually adds strength to the body if famine is temporary.I have been practicing IF for 2 1/2 years. I just had a check-up and everything is in working order plus I lost 34 lbs.

    So the starvation mode that the experts like to believe in is most definitely BS.Ketosis is not.

    1. Mary, regarding your statement:
      “I add cream and coconut oil to my morning coffee. So even when I am not taking in solid food, I am consuming fat.”
      I was wondering if this is during your IF time. Is having fat during IF period okay because it does not trigger an insulin response? I heard that coffee does trigger an insulin reponse, though. I would love to be able to have coffee and cream during the fasting part.

  132. Maria,
    My opinion only – but an adjustment in thinking might free you up – when you are not concerned with how many calories are in the food you consume you will find it quite liberating…
    low carbing is quite simple – it’s about taking out the old starch staples like rice, bread, pasta, too many potatoes cooked the wrong way – I actually do eat potatoes (in small quantities) but only in soups and stews and raw in juice… It depends on what you personally think you can live with/without… some people change to the wholemeal starches but I preferred to take certain things out completely… I do eat oats in my home-made museli but only a little…
    So then low carbing becomes “what can I eat with the foods I am allowing myself?” It will be different for everyone…
    my vegetable juicing means that I probably obtain quite a few carbs but I consider it worth it for the nutritional trade-off – I use green apple for taste moderating purposes but largely fruit is not part of my juicing routine as it has a high sugar content generally… that doesn’t mean I wouldn’t have a nice fresh mango in season if I want – I’m not that extreme…
    Also on the hunger aspect of daily fasting – it’s again a mental adjustment more than anything – I have changed my own personal classification of hunger to suit the way I want to live my life… for me, a few growls in the tummy is not hunger – but perhaps falling down faint is – it’s personal for you… How you classify hunger for yourself is personal and nobody can judge that for you…
    I get growls in my tummy in the morning and I drink copious cups of Japanese tea (my current favourite) and if by 10am I’m feeling like I’m about to fall down – I’ll do a quick cabbage and green apple juice and it satisfies me nicely… it’s not solid food but it is solid nutrients that go straight to the heart of the matter…
    Coffee is good as a quick appetite suppressant but I just don’t like the bitter aftertaste of coffee… my personal preference (I’d love to love it actually – my husband brews up coffee in the morning and it smells so good)

    This is my experience…

  133. Totally agree especially with the mentalisty of hunger. In addition to hunger, it amazes me that we equate hunger to starvation. I mean, I am often sleepy without equating that to being sleep deprived.But I hear comments on how you shouldn’t have to starve yourself. Well, going hungry for a couple of hours is far from starvation. Those who are truly starving don’t even feel hunger.

  134. I have to say that in January 2009 I lost 10lbs in one month by fasting. I exercised 40 minutes 5 days a week and at once a day around 2 or 3pm. I felt great! I became pregnant shortly after and had to discontinue. I will do this again once the new year begins and I know I will have great sucess. I felt great the entire time I was fasting. This is the best eating routine to follow and the easiest to maintain. Maitainence is key!

  135. I started my first rotation of IF on sunday night at 6PM. I went from Sunday at 6PM to Monday 6PM. I only drank water and calorie-free tea. It was surprsingly easy. I can say that fasting from 6pm one day to 6pm the next is easier than fasting a whole day from breakfast, because even though I am fasting a full 24 hours, I am still eating everyday! Today is Tuesday and i just started my 2nd 24-hour fasting rotation for this week. I will go until tomorrow at 6PM! Fasting is such an awesome tool!

  136. Nice idea for a posting! Longtitudinal studies are needed to verify any claims that alternate date fasting or fasting in general is healthful. You have to observe people’s health over decades to determine whether it’s healthful. Short studies of a few days to a few weeks are not enough of a window into the benefits or cons (says I!)

    Animal experiments have poor generalizability because they lead very different lives to humans. They have different sleeping patterns, social habits, activity levels, nutrition, and stresses. Lab animals are also bred for specific gene combinations and for all these reasons animal studies are pretty uninformative in this instance.

    Keep coming with the thought provoking material!

    1. I would like to fast for a few different reasons. The first is to lose weight. Right now, I have a BMI of 42 and I have reached a point in my life where I am tired of being like this. Secondly, I have become more and more aware of all of the toxins which I have ingestedover the years, 42 to be exact, and I would like to detoxify my body. Lastly, there are the spiritual reasons. So, my plan is to fast for 2 days, eat one, fast 2 days, and eat 2. I’ll continue this for an undecided lengthof time, then adjust my fasting/eating ratio as necessary. Anyone have any advice or input?

  137. James W., There are many studies that support the healthfulness of fasting.I was one of those who decided that I was going to stop standing on the outside, looking in, and try it for myself.Afterall, my diet was already healthy, therefor I must be healthy enough to start this. From that standpoint, all of my residual joint pains ( that had not completely cleared up from initial low carbing ) vanished. Yes, my joint pain improved greatly since I began doing Low carb. I also coninuted having auras although I no longer suffered with migrains. However, after balancing my body with IF. The residual joint pain and auras became history. In my honest opinion a low carb diet accompanied with intermittent fasting is how I am healing my body. Now all of that being said, I feel free to declare that I lost 35 lbs since beginning IF 2 1/2 years ago. Yes, the loss was slow but I would much rather lose 35 lbs in 2 1/2 years than to gain it.

    Lemontrail, before you begin your journey into fasting, take the time to examine your diet first. If you feel like your body is full of toxins, you must feel unhealthy. In my honest opinion, fasting can only be as healthy as the food you eat. For example, if you eat a lot of high sugar/carb laden foods, your insulin levels must be helter skelter. Remove those from your diet first, or at least a huge part of them. Eat healthy meats and vegetables and allow yourself to experience ketosis. Fasting in itself is ketogenic so you do not want to fight with that.

    As you improve the healthiness of your diet then ease in to fasting. Keep in mind that fasting is actually something that we all do. If we didn’t the term “breakfast” would not exist. What you want to do is extend your fast beyond the usual 10 or 12 hours by eating progressively later in the day. If you normally eat at 8:00 A.M., eat an hour or two later each day until you can go until any time that you want.

    Then as your body becomes stronger and more adapted to your new lifestyle, then make the needed adjustments.

  138. Another thought James, earlier humans that had no conventional ways of cooking or preserving their food probably did not eat 3 times a day with in-between meals. They could not go to the local deli or purchase a months worth of food. They had no McDonalds, Krispy Kremes, or Pizza Hut. They spent more time hunting and gathering than they did eating. They spent more time building shelter and sewing clothes and fighting rival tribes than they did eating. Fasting wasn’t even a word…they just did not eat as often as modern humans do today.

  139. Hey mark, I just wrote a blog post about my first experience with Intermittent fasting. You can read it here: The amazing part was I got STRONGER in the gym in everything. I even hit 2 lifetime personal bests in a couple lifts. All while working out totally fasted. ….so much for conventional wisdom.

  140. when fasting during the day, is it ok to consume black coffee, tea, and diet sodas? should i worry that they would interfere with the fasting/cleansing process?

    1. I consume coffee with cream during my fasting hours. I also put MCT oil in my coffee. I use fats during my fasting hours. In my mind it accentuates the ketogenic benefits of fasting.

  141. I think there are any amount of variantions of this… to be technically fasting then there would be no calories consumed whatsoever… I think most people would be sipping on something – even if it’s just water… but for me (and this by no way constitutes advice) I make my own vegetable juices – no pulp – I stick to carrot, beetroot, celery, cabbage and very small amounts of green apple (to make the cabbage more palatable) it works for me… I saw a post above where someone did papaya juice fasting so there’s another variation for you… I would stay away from fruit as it’s high in sugars… (having said that I do add the green apple to my cabbage juice) so play with these ideas and add your own… see how it works for you….


    Fasting is the abstenance of food. Or to go hungry. You can abstain from food and still take in calories. You can take in calories and still go hungry. Fasting is ketogenic so I take in fats during my fasting period to support the ketogenic benefits of fasting. Fats provide energy without stifling hunger.

  143. I just started intermittent fasting five days ago. I fast from 9pm through 4pm the following day. I have been observing a paleo diet and doing Crossfit 4-5 times weekly. On the fourth day of my intermittent fasting I did a new ‘hero’ workout at Crossfit that consisted of 3 rounds of 25 muscle-ups, 100 squats and 35 glut-ham situps. I had not eaten anything since 9pm the night before and the results were astounding to me. My first round was 12 minutes, my second round was 13 minutes and the third was 14 minutes. There was very little drop off from round to round when normally my later rounds in Crossfit work outs drop significantly. I never ran out of energy even though the most muscle-ups I have ever done in a single work out was 30. I was able to do the first two rounds of 100 squats unbroken, in the past my max was around 60-70.

    I am truly amazed at the amount of energy I have following intermittent fasting. True, it is early on but so far I have to say it has worked for me really well.

  144. I am not athletic nor do I lift weights. My activity primarily consists of walking. I had not been walking for a while and was recently diagnosed as pre-diabetic. I want to get my FBS below 100. I added walking to my loe carb based IF, plus a good amount of vitamin D. My blood sugar is below 100…well at least today it was 96. I feel that I must continue some form of physical activity along with my other detary commitments if I do want to prevent full blown diabetes onset.

  145. Hey Mark,

    Thanks for this article on IF…I have been interested in reading more on the topic so this couldn’t have come at a better time.

    1. Here is my feeling on the matter. First off, teens tend to do crazy things. You know this to be a fact. That being said, many kids eat very similarly like this, naturally. Eating healthy is imperative, regardless of what your lifestyle is. Remember the idea of IF isn’t to consume fewer calories. Many people do this when they do intermittent fasting. If you eat healthy, you will be fine. If you do this on a gradual basis to allow your body to acclimate to low carb. Please, don’t restrict your fats and eat your vegetables. No dessert for you!!! That is my opinion.

  146. I had a very agreeable experience with IF. I followed the Fast-5 approach for 3 months. I lost fat, food tasted much better and I generaly felt good. Not to mention the money I saved on food. I have a question though as I try to get back into the lifestyle. One that anybody with experience is welcome to answer. I want to be thin yes, around 6-8% body fat. But more than that I want a nice looking set of abs and a well defined body. Can this be achieved with IF? Maybe interval cardio in the morning for extra fat burning, and strength training after I eat so I have the calories to go after it hard. Anybody out there who IF’s and is decently cut? Thanks!

    1. Jeremy, I think IF is an essential tool in bagging a six-pack. Mine is still a work in progress (four-pack?) but IF has chiseled it to where it is now. Sterling’s six-pack is cut to ribbons and I know for a fact he IFs frequently. There’s another gentleman out there, whose web site unfortunately escapes me, who does a 20-hour IF every single day (a little meal before the evening workout, then a big meal) and he is shredded to within an inch of his life.

      So hit that IF, and hit it good. Just remember that hunger is the best sauce!

      1. Thanks a bunch Tim. That makes me feel really good about my decision. If you do remember that gentlemans website I would love to take a look at it.

      2. Hey Tim, who is “Sterling” and how do I get in contact w/him. I have an excellent background in nutrition, but don’t exactly know where to start for the combo of muscle building and IF’ing. Thanks!

  147. Jeremy, now that you have an answer from someone who is truly muscular. I want to add that muscle building while fasted is necessary because it does activate growth hormone even in older adults. Growth hormone maintains muscle mass. Also, carbohydrates will kill your growth hormone especially if you consume them within the hour following your workout. Fat is of course chief ketone producer. I learned this from Protein Power written by Drs. Mike and Mary Dan Eades.

    I am by no means a body bulider nor am I chiseled. But I walk while fasting and do not eat until after an hour has past after I am done walking. My body responds the best when I exercise while fasted. If I decide to lift weights, I would do it the same way.

  148. Well what I have been doing lately is, every monday I wake up and just fast until dinner time. So whatever time I get done with dinner on Sunday night until dinner the next night which is usualy not quite 24 hours. I drink lots of water but force myself to drink a lot of water always. The first thing I do when I wake up every morning is drink a tall glass of water then for for the coffee ect. Not tues through Friday, I eat healthy. 3-5 smaller meals a day with veggies, meats, good complex carbs. I discovered something called almond milk that you can buy which only has about 40 calories and it takes the edge off of things cause it tastes kind of sweet and is an enjoyable treat in the evenings to drink a glass of the unsweetened vanilla kind. I try to work out 3 days a week lifting, and two days a week doing cardio on a bike and maybe a run instead ect. I am getting amazing results. On weekends I let it go and eat some junk, pasta ect. But anyway I am getting much bigger in muscle, and the weight is coming off nicely. I have almost a 4 pack right now. so keep on keepin on! I do lift and spin on my fast day and have NO problems.

  149. Hi guys! I stumbled upon this website whilst researching intermittent fasting. I have been trying the fast 5 approach for just over a week now and it’s great apart from one thing. I work in a rather active job which starts at 7am. As the morning goes on I begin to feel very fatigued and weak. This isn’t accompanied by dizziness or faint feeling – just a feeling of “can’t be bothered”. I feel like I’m running on empty – which I kind of am. Previous to this i was eating a lot of fruit for breakfast and mid-morning snack (Im vegetarian by the way). I guess my body is used to using these quality fruity carbs as fuel and not it’s own fat stores. Any ideas on what I should do? Eating a piece of fruit usually sorts me out enough to keep going but then I have triggered the “limbic hunger” and also lose the hormonal benefits of fasting. Any ideas on how to combat this fatigue or what would be the best thing to eat if I really have to?

  150. I am a faster who consumes fat during her fasting hours. I put coconut oil or MCT oil in my coffee along with heavy whipping cream. This gives me a boatlad of energy. I feel that oils or fats are perfect to consume during thr fasting hours because, like fasting, fats are ketogenic. When it comes to fats or oils, I do not count the calories. Sometimes I put MCT oil in my drinking water. If you are not accustomed to injesting oils like this, don’t use too much, you will regret it. Just take a small amount but do try to increase it. But do remember, fasting is ketogenic so you need to keep your ketones at higher levels. Don’t neglect that. My weight is much more manageable with the help of MCT oil and coconut oil.

    Also, make sure that you don’t do this cold turkey. Your body needs time to make adjustments.Consuming a lot of fruit is very high in sugar. Your body needs the time to switch from using sugar as fuel to fat burning mode.

  151. I have just started using fast days. I have been doing primal for a couple of months but was wanting to kick start things as I hadn’t yet lost many lbs. So I did a 24hr fast twice two weeks ago and another a week ago. I have also been keeping my carbs low. The only thing is I am starting to feel strange side effects. My pupils are dilated and I feel wired. My head is so active at the moment. I seem to be reading voraciously and I actually feel more intelligent. But I also feel like I am on drugs. I have so much energy but it seems to be collecting in my head. I am also finding it hard to sleep because my mind is soooo busy. I think my brain just running on ketones and caffeine. I had to eat an apple just to stop me tripping out.

    I also have been doing high intensity workouts and did a spot of sprinting, so I don’t know whether I am feeling a genetic response to that. I doubt that I would actually feel myself changing.

  152. I would guess that since you are fasting and doing low carb, both support ketosis especially if you are consuming fats.MCT oil wil especially give you a jolt of energy. You probably are experiencing ketosis which is superior as an energy source. Ketogenic energy feels like you could take off running without moving a muscle. At least that has been my experience. Your brain is also running on ketones and that is probably what’s keeping you up at night.
    is my experience.

  153. Okay, as long as this is normal. I thought it may be ketones, but tested my urine with ketostix and it didn’t really change colour. My girlfriend did notice the old breath thing though. I ate some boiled eggs and dried beef, feel a bit better now.

  154. The reason you see no evidence in the ketostix is because you are probably keto-adapted. In other words your insides are using the ketones which would keep them from being washed into your urine. It is a good sign to “feel” kketosis without seeing them in the test strips.

  155. Thanks Mary I am glad it is ketosis. I found myself looking up hypoglycemia and all sorts of stuff just incase it was something else

    I wonder if I had a bit of a biological tipping point where my insulin sensitivity increased quite rapidly. Due to implementing a lot of principles simultaneously. Hence it felt more powerful than I was prepared for.

  156. Oh and I seem to be 2lbs lighter today than yesterday. I know it can easily fluctuate but it is a lot lighter than I have been in a long time.

  157. As a Mormon, I have fasted monthly for forty years. The only problem with that is that it’s common in Mormonism to abstain even from water. More recently I have “discovered” fasting like Mark. I no longer agonize over missing any meal, and I have fasted for days with complete comfort and enjoyment. And, like a lot of others who’ve commented, I see important benefits from my nightly fast that is often long enough (12 hours) to start ketosis.

    A side benefit is when I have the time and setting to eat, I can truly enjoy it without counting calories or measuring portions. My only eating limit is how I feel afterward.

  158. I’d love to try this. Can anyone recommend a “schedule”/plan for a beginner? Or should I just give the 24 hour fast a shot right off the bat?

  159. John whenever anyone asks me how they should do this, I always say to take it slow. But stay consistant. I began IF just by making breakfast progressively later each day. For example, I normally ate at 6:00 AM. Then I changed that to 8:00 A.M. then 10:00 etc. Eventurally I was able to go until 2:00 or 3:00 PM before I broke my fast. Now, I may not even eat until 5:00 PM or 6:00 PM if that is my heart’s desire.

    1. Thanks for the advice. I think I may just try it for 24 hours (dinner to dinner) and see how it goes.

      Would you suggest not working out during that fasting period? It’d suck to go for a run and pass out or something.

      1. Well, I am not an athlete. My physical activity is primarily hour-long walks. I walk when I am fasting and try not to eat until an hour after the walk. I plan to progress to running since I want to participate in a 5K run in November during my fast. Fasting kicks up your body’s ketogenic abilities and once you are keto-adapted, the ketones will be used as fuel.

        It surprises me that I have been able to remain physically active and feel just fine. Being that fasting is ketogenic I add fats during my fasting hours. For example, I will add MCT oil or coconut oil to my coffee. I have also added MCT oil to my water. MCT oil is an instant energy boost.

        John, you know body best,try some physical activity but don’t go trying to
        hunt buffalo or bench press a walrus. But see just what your body will allow you to do without over doing it. I find that my body responds best to exercise when I am fasting.

        1. “I find that my body responds best to exercise when I am fasting.”

          Very interesting, I am excited to give this a shot.

        2. In that last paragraph…I mean to write. John, you know YOUR body best…

          But anyway, I have done IF for 3 years and everything that I write has been my honest experience. This is what i do everyday.

  160. Mark, what do you think about Martin Berkhan and Leangains?

    Just recently discovered his blog He’s held in high regard by a lot of people that I respect such as Robb Wolf, Lyle McDonald and Alan Aragon. I also saw him mentioned on Nikoley’s site recently.

    Tons of clients and testimonials on the site. Seems very competent. Anyone here tried his method? It involves a shorter fat (16 hrs) than the norm and then an overfeeding phase after training. Just curious if anyone here or Mark had an opition of this fellow or this particular approach.

  161. I hope someone can help me answer this question. I grew up on the Canadian border (the Great White North, as we affectionately call it), but now I live down south. I’ve always found that when the temperature breaks about 75, my appetite drops to effectively zero. I will feel like eating maybe once every day or two. I do consume treats like frozen berries to cool down, but other than that, I’m almost never hungry. Should I embrace this as an IF opportunity in the spring/summer/early fall, or should I continue to eat on a normal schedule even when I don’t feel like it?

  162. Personally, I believe that if your body is telling you to fast, as you describe, that is the best time to do IF. This is probably what your body wants and it won’t fight you on it. I do encourage you to eat the healthiest of foods, which includes the right fats, and IF will carry you a long way.

  163. My only question is: why are many IF plans very strict when it comes NOT eating during the fast period? I can understand a feast every one or two days, but it would also seem that Grok would eat whatever he came across — small game, nuts, berries — whenever possible, sort of like snacks.

  164. Although Grok would probably eat every opportunity that he got. The problem is he didin’t get that many opportunities especially during the winter months. Even though IF might seem to be strict, I would be willing to wager that IFers still eat way more food than Grok, Moogie,Leeba, Deeba and Mark put together.That being said, I do think that fats such as MCT oil should be perfectly fine to consume during the fasting period because of your question. Realistically Grok did not fast out of choice. Grok fasted because he had no other choice.So when the opportunity arose, Grok took advantage of it. I put MCT oil and heavy cream in my coffee during my fasting hours to enhance ketogenic qualities of IF. I go until 3:00 P.M. before breaking my fast.

  165. Hi. just my pennysworth; I have been doing Brad Pilon’s eat/stop/eat since January, and have been basically fasting from supper to supper 2 days a week, with coffee (unsweetened, naturally) only in the fasting period. I have lost about 1kg a fortnight with no problem; as of April, I kicked it up a notch by going uber-paleo (Ice Age Paleo); only meats and lots of fats, eggs, little bits of green salads – NO fruit. the weight loss increased to 1kg a week.

    in the last fortnight, I have started taking 1 teaspoon of flax oil + 1 teaspoon of hempseed oil in the morning of my fasting days; since doing this, my weight loss is now 1.5kg a week for the last 2 weeks. Adding the fat seems to have “turbocharged” my weight loss, and certainly has killed any hunger till supper. I think it helps that I only eat fat and meat when not fasting, because that puts me in “fat burning” all the time, so the fast is effortless (I fast on my busiest work days, when I would struggle to find time to eat anyway).

    thought I would share what is working. by the way, my blood work is BETTER since cutting the fruit and veg – higher HDL, lower Triglycerides – and I have no fatigue at work.

    I work as a Family Doctor, and reckon this diet would be fantastic for a Type 2 diabetic – with all the usual caveats of making sure you discuss it with whoever is helping you with your healthcare (in case you are on prescribed meds).

    best in health to you


  166. Bill, thanka for sharing your results.I like the fact that you have drastically cut your fruit and vegetables and that you eat so paleo. I too believe that it is the ideal diet for T2 diabetics. I am pre-diabetic and it is helping me with glucose control.

  167. Linda, I do not see your post on this blog, but I did get it in my email. Just to let you know fats will help lower glucose, at least for me. I have done extensive experiements on this and I know it to be true. The fats I use are butter, MCT oil and coconut oil…all saturated gats. I beleive that they lower glucose by improving the cells to become more receptive to glucose, similarly to chromium.

  168. I am confused by all the things I hear about low carb/high carb, low fat/high fat, vegetarian/meat. I did it all and my triglycerides/obesity/glucose is awful now. Presently I am losing weight by eating a good sized meal every 48 hours. Fats raise my morning glucose level but then I had a carb with it so maybe it is delayed carb absorbtion. If I eat carbs I am better off not having the fat or meat. I can’t seem to do both. Fruit is deadly for raising my glucose and so is wheat. I do ok with nuts, seeds, soy, green vegetables, protein analogs, and lemon for vitamin C. On the days I don’t have a meal, I have bullion at supper. Last week I went into ketosis and I felt weak and bad. So this week I might allow a cup soymilk and a few crackers at bedtime. I did that last night and my glucose was 100 this morning and my energy good. I ate every 48 hours to lose weight after children in my 20’s and it worked very well. Then fasted one or two days a week for maintenance. Then at 40 became disabled and hypothyroid and packed on 100 pounds. I’m 52 now and rediscovering IF. I am very happy to not have to worry about what to eat all the time and enjoy when I do eat without all the guilt. I am free to not feel I will die without a meal. I no longer feel ostracized for having to eat “diet” foods around other people. Thanks Mary Titus for your comments. Maybe I can tolerate fats better when I am no longer obese. At the moment I am still confused about food groups. I only know one thing IF works for weightloss and glucose control. Ya’ll pray me skinny. I’ve got one week down and probably a year to go and I need people like ya’ll to have people who do not go against my progress as most people are against fasting. But it is the only thing that ever helped me in the past. Calorie counting, measuring is just too much work. Fasting naturally causes portion control anyway because I can’t eat as much after a fast. I also don’t have asthma when I fast.

  169. Hi linda

    I am sure you already have Mark Sisson’s excellent “primal blueprint” book – but I would also recommend a complementary book, “primal body primal mind” by Nora Gedgaudas. I am pretty sure you are sabotaging your efforts by allowing too many carbs and too few fats in your diet – her book spells it out nicely and dovetails with Mark’s carbohydrate curve.

    Many people try to use IF as a standalone solution; it works SO much better when your diet puts you in fat-for-energy mode 24/7. Your body has NO requirement for carbohydrate. Zip. Nada. Zilch. You just need moderate protein (a portion of flesh food/eggs/cheese the size of your hand) and enough fats (mainly saturated fats for energy and some flax/hemp/fish oil for the essential oils) to satisfy you. Ask any Eskimo, veg and fruit is not necessary for health. Include them for variety or taste once you are healthy again, but till your weight/ sugar issues are normalized – regard them as nonessential.

    Most confusion comes from people cutting carbs and trying to eat lo-fat : it cannot work! IF on a high fat, mod protein, lo carb diet simply ROCKS.

    Try it & let us know how you get on

    best wishes

  170. Ketosis will make you feel weak because you are using fats for energy. Your body has to adapt to the new energy source by producing the right enzymes. This takes time. Don’t ask how much because everyone is different, but once the right enzymes kick in, energy will return. So by raising carbs you will reduce ketosis and the enzymes needed for “carb” energy will return quickly because they had not have the chance to “die”.Stick with ketosis long enough to produce the enzymes needed to kick those ketones into fuel. Do not fear fats, unless they are transfats. Fat will make you thin because it is a natural energy source. It is more than an energy source, ketones girds your bodies tissues including heart, brain and muscle cells.It doesn’t matter if you are obese or not fats are not idle, they have a job to do if you allow them. Eat carbs, and your body will store fat so that the body will have energy for those “lean” days.Just FYI, soy is bad for healthy thyroid function, coconut oil is good for thyroid function.

    You should also seriously begin taking vitamin D3.Read about vitamin D, get tested before deciding how much to take.

  171. Hi again Mary (and all)
    I am in agreement regarding the medium chain triglyceride oils/fats… I was doing what you suggested and having coconut oil in a morning coffee with double cream and it certainly acts as an appetite suppressant – I recently started to have an aversion to coffee though and it’s terrible in tea… so now I mix a teaspoon of coconut oil with a teaspoon of almond paste, peel a carrot and make sticks out of it and dip it in the coconut/almond mix… I’m usually moving around getting everyone ready in the morning so I can take half an hour over eating it… I enjoy the satisfaction this gives me until lunch time – for the rest of the day I eat low carb as possible… I feel great – weigh 56 kilos and have stabilised at that now for over six months… I support the “ask the native alaskans” theory about whether we actually need carbs or not… I’m very conscious of eating as much fish as I can and green vegetables… I do eat some potatoes but try to limit white foods generally… I’m now thinking I should even cut the small amount of potatoes I eat as I may be sabotaging my body’s efforts to create the right enzymes… Mmmmm… thoughts would be appreciated…

    it’s hard to work through the stage where we are teaching our body to get it’s energy from fats… it hurts… also I encounter lots of opposition from friends and family which I find is a daily combat…

  172. I got a lot of oposition too…don’t get it no more though…I wonder why? My family suffer from metabolic issues, namely diabetes.I don’t eat potatoes but I do enjoy turnips and cauliflower. I eat them both mashed and I make french fries from them. I also eat pumpkin which is an excellent replacement, nutritionally, for orange vegetables. Bell peppers of all colors are also a wonderful choice for healthy veggies and/or fruit.

    I eat a very limited carbs all day.For example, today I broke my fast with steak and eggs a few slices of tomatoes. For dessert, I had few pieces of cantalope and strawberries. I snacked on some peanuts. I

  173. Thanks for the feedback Mary…
    Are you still aiming for weight loss or are you at your goal weight already?

  174. I do hope to lose 10 more lbs. I also plan to run in a 5K in November. If I do this, it will be while on a low carb diet and I will be fasting at the time. Two ideas that go totally against the grain.

  175. I really feel great fasting until dinner 2-3 times per week. It simply gives my digestive system a rest & I’m full of energy.

    My tip: If you do decide to do intermittent fasting, don’t eat a huge meal for dinner (like the Warrior Diet recommends)…better to eat a regular size dinner (like Eat Stop Eat recommends).

    This is a simple way to create a calorie deficit over the week and lose weight. It also gives you some wiggle room to have a few higher calorie days while still losing weight.

    Great topic,

    -George D

    1. I have been doing the 16/24 fast for three weeks now. I feel great. I eat at night. The problem is, I work out vigorously when I get up in the morning do to family and job commitments Before my work out I drink 8 oz of skim milk. After the workout I drink a protein shake. I count this in my daily calorie and protein intake. I then fast the rest of the day till the evening. Is this a good way to IF. Or should I just not eat at all around my work out.

      1. Personally, I believe that fasting is what you make it. But personally, from my experience you do not need the protein drinks in the morning…especially the skim milk.ANd you will be surprised at how well your energy levels stay at optimal levels without any additional help. The dawn phenomenon is a process in where the body’s glcuose levels increase overnight. In general these levels are highest in the AM showing that the body prepares itself for morning activiities without eating. That being said, I usually have a little MCT oil in the morning to kick up the ketogenic qualities of fasting.

        1. Mary

          The reason I work out is to build muscle. I am not concerned with my energy level. I do have enough energy in a seated state to work out pretty hard. I am just worried that if I don’t have protein around my work out, I will lose muscle. So are you saying that I will still build muscle without a recovery drink? I know people will say to work out right before I break my fast. That is mostly not an option for me. And eating all my calories in the AM would be very difficult for me. I would want to sleep in the afternoon. Or wouldn’t be able to eat with my family.

        2. Not seated state, I ment fasted state. My iPhone likes to make the wrong corrections sometimes. LOL

        3. Robert, from what I have learned is that the best time to workout is while you are in a fasted state…and you really should not eat until an hour has past following your workout. Hopefully,you ate enough protein the night before to easily sustain you until your next eating window. What this does is ressurect the production of growth hormone which maintains muscle. I learned this in Dr. Mike and Mary Eades book “Protein Power”. Eating just before and/or soon after a workout kills the natural growth hormone ESPECIALLY if that meal is in the form of carbohydrates,( for those out there who believe that carbohydrates are so important ). I do understand how your schedule can get in the way of your IF goals. I face the same problems. Use your knowledge to balance your schedule and IF. But I will stick to the ideal of eating too soon around a workout is detrimental.

          SOmething else to consider are ketones which are very potent when it comes to maintaining muscle. That is the purpose of ketosis in the first place.Fasting enhances ketosis as does MCT oil which is like instant ketones. I would consume ketones in the form of MCT oil, a derivitive of coconut oil. MCT oil blends quite well in water or tea.

          Hope this helps.

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  177. Something for all to concider, The new Twilight series is a major hit. Now Jacob in the movie has an 8 pack and is in unbelievable shape. Brad Pitt in The Fight Club, Jason Statham, the transporter ect. Ryan Reynolds, Blade trinity, amityville horror. All of these celebrities worked out at least 5 days of week with at least 1 day of cardio and they ALL ate 5-6 small meals a day while rotating carbs or fewer carbs. And look at ALL of them. They are in GREAT shape!!! Are we sure that they aren’t living proof that that is not a bad system??

  178. Well, see what it does for you. If eating 6 times a day keeps you svelte and sexy then you are doing what’s right for you, Jeff. I can tell you right now that, as for me, if I ate that way, I would be an overweight diabetic with a horrid craving for doughnuts and Lays potato chips.

  179. Brad Pilon just put out a YouTube video on the “6 meals a day” subject. The gist of it is that when the theory was developed, the extra “meals” were only 45 calories each. As he pointed out, just putting cream in your coffee is a “meal.”

    As far as carbs and working out goes, you’re looking at information coming from competing interests. Energy for your workout has to come from somewhere. If you eat 200 calories of carbs before working out, your body will use those carbs as energy, before burning any body fat, since carbs are a preferential source of energy over accessing fat stores. If you exercise fasted, your body has to pull it’s energy out of your fat stores. So a person who wants to burn off some body fat needs a different strategy than a person with low fat reserves.

    When you’re talking about the Brad Pitt’s of the world, I suspect the diet is more about getting carb energy to fuel a long muscle building workout, since there probably isn’t a lot of fat to burn.

  180. I have been eating less recently and eating less frequent. I am enjoying life this a lot more. Fasting has a place in my life. I don’t do it regularly though.

    If I am traveling and good food is not around then I will no longer feel guilty about skipping a meal!

  181. Hello all you IF’ers out there in computer land. For those of us (myself included) who want to look like Ryan Reynolds in blade or something close to it. Through my seemingly endless search of the interwebs and my correspondance with Timothy from this blog. I have stumbled upon the holy grail-if you will-of IF and getting ripped. The site is called Martin Berkhan is a genius and gives you all the info you need to succeed on your own. Check it out, you will not be dissapointed.

  182. Mark!
    Thanks for the wonderful website. I’m very new to IF and would like some advice. I’d like to combine IF with the condensed eating window. Here’s what I was planing to implement, please critic and refine!

    Fast from 7:00 pm until 6:30 pm
    Eating window 6:30 to 7:00 pm

    Repeat cycle.

    Does this sound healthy, assuming I’m getting the correct nutrients during my eating window?

    Thanks for any advice you can provide.

  183. Mark,

    Just wanted to throw my two cents in here… I did a fast only drinking water 85% of the time and coffee and DIET soda for the other 15% for 72 full hours. Let me just say that I felt great. No hunger pains, no brain fog and plenty of energy. I did not go to the gym those three days, but just did some walking. I was following a low carb/paleo eating plan at the time. If you tried doing this after being on the standard high carbohydrate diet, you would probably get massive headaches and feel very weak. I was simply amazed at the results. I felt much better and plan to start doing IF more often, not necessarily for 72 hours each time, but at least 24 hours. The key to making it work was drink lots of water, it keeps you full and satisfied.

    Mark thank you for all that you do. This website is so helpful and has changed my life.

    -Nick S. Chicago, IL

  184. Hey Mark,

    Great stuff you got here. I adhered to mostly primal lifestyle now and am having results. When I have better results, I will post it on your site.

    But, I am interested in knowing more about IF for people with diabetes. Can you shed some light in this area ?


  185. I have pre-diabetes and I am able to improve my glucose levels on IF. I do IF on a daily basis and I build my health on intermittent fasting. The more paleo I can keep my daily menu the better my glucose levels. But what really was a boon to my health was the discovery of magnesium deficiency. This came about after I had read that low magnesium levels among other nutrients can manifest itself through headaches. I began taking magnesium for my headaches instead of OTC pain relievers which worked just as efficiently as the meds.So I began to ponder a conection between headaches and insulin resistance. So I researched magnesium and found out that one of magnesium’s job was to manage blood glucose and insulin. I began taking magnesium on a regular basis and my glucose levels have been well within the normal range.

    I just read an interesting article on enzymes and it states that during fasting our body goes through an increase of enzymes making them available for healing and repair. The article actually was pointing out the importance of consuming raw foods and how their consumption also contributes to a higher level of enzymes circulating in the blood.So I am considering increasing raw foods in my diet…something that I have never considered before. Hope this helps


  186. Thanks for sharing this.

    I know when I first heard of fasting I was extremely sceptical, especially after I had been eating 6 meals a day for 5 years!

    After taking a leap of faith with the worry that all my muscle would vanish I tried it, and to my amazement it was amazing. I’ve been doing it for about a year now and have found it incredibly easy.



    1. Tom
      What exactly have you been doing for the past year? And how did your body adjust to the switch? Have your workouts changed? I’m definitely a grazer, but would love to try IF. Anything you could share would be helpful.


  187. One of the strongest arguments against intermittent fasting is that it will slow down your metabolism. In one study, intermittent fasting was associated with more than a 40% reduction in heart disease risk. Fasting was also linked to a lower incidence of diabetes. The study was published in October in the American Journal of Cardiology. We just have to burn those hidden fat in the phoenix self storage.

  188. I practicing intermittent fasting and believe it works great for maintaining my weight and fits well around my lifestyle which involves strength training and some running. I do however feel some of the other commments here detract from the potential validity of IF when they start mentioning ‘nerve energy’ ‘toxins’ and other voodoo, toxins are a myth splashed around to sell bull**** diets, supplements, books etc and I don’t even know what nerve energy could possibly mean. I also think some here are getting abit too excited about animals, which are usually alot less relevant than you may think. Just trying to add some perspective, yours sincerely, a fan of IF

  189. So here is what I have been doing. I have tried every diet out there and had some success with all. I finally bought Brad Pilon’s book Eat Stop Eat and applied it. I fast two 24 hour days a week, I drink black coffee and lots of water during. Then I break my fast and eat like I normally would. No huge meals or anything like that. I excercise 3-5 days a week doing P90X mostly.
    When I wake up ill eat in an hour or so. And then I just eat a bowl of oatmeal with brown sugar and a little cream, or maybe ONE pancake, or a couple of eggs. Thats it, then for a snack I MIGHT have a handful of nuts I might not. Or a protein bar. Or not! Then for lunch I do a half sandwich and soup, or just a small meal of fish and broccoli, chicken and noodles and cream sauce whatever but the point is, the portions are small!! If I went to Pizza hut for lunch I would gorge myself with the salad bar eating only SALAD, Peppers and thats it, and then I eat two slices of pizza and no more. So I enjoy what I eat just not a bunch of it!! at dinner I eat whatever, spaghetti, pizza, steak and potatoes a normal dinner and one generous plate and thats it. At evening ill have a few chips, or some gummy bears, or a beer or two and thats it. The first two weeks alone of this diet, I lost 10 pounds. I am down to 179 which is about as light as I have ever been and no diet has given me results like this one does. I keep my calories to about 1200-1700 a day preferrable but if I go over like I did yesterday where I just pigged out on candy bars after halloween, I don’t care! I am fasting today and ill eat better the rest of the week with another fast and excercise and ill still be in a caloric deficit! And my muscles are GROWING!!:) Remember you MUST BURN MORE THEN YOU TAKE IN!! Forget protein!! forget carbs, ect. eat more veggies and fruit always, and burn more then you take in, you will lose weight and if you do strength training 3 days a week, you will build muscle if you lift heavy for 8-10 reps a set. if you lift light you will get lean and not lose muscle! I hope someone else has as much success as I am having after reading this. My 6-pack is almost here for the first time in my life!!!!:)

    1. What kind of how old are you?
      Are you M or F?
      What kind of exercise and how much are you doing?

      And really Gummy bears? I would rather have a steak but to each their own.

      I put in my routine on a post today if you want to know what I do.

      Thanks, and congrats on that 6 pack. I want to see that on me within a year.

    2. Dude uless your 5ft tall, at tf ease.

      You don’t really explain how you fast and what your doing besides eating anything you want kinda but your were only 185 lbs. that aint shit either be more specific in you body and orig weight or get real. I am 269 lbs and have been as high as 298 lbs and been as low as 210 lbs and am 6ft tall. so I need to figure out how to keep it off, i have been doing the BFS every day and fasting everyday but one night a week but really not sure what I shoud be doing for the IF but you loose 10 lbs at your weight , i have lost twice that in a week like nothing. I think you need to just work out harder and finally did it, sorry but congrats to your new found thing.

  190. Ive been doing a fasting diet where i fast for 16hrs (usually from after dinner) and at the end of the fast you have a half protein shake or 2 egg whites to stimulate production of bcaa and hit the gym a hour after that or go for run on non weight days, and then have a big hit of protein and carbs (usually 3 whole eggs and 3 egg whites scramble on toast) and banana or something, then later with dinner i make sure i get 2 cups veges to get the nutrients ive missed out on (you can add a multi vitamin) and then once a fortnite mix it up with a 24hr fast. THIS REALLY WORKS I have dropped 5% body fat and gained 2kg muscle so far!

    1. That sounds great, but where are you starting from?

      where was your body fat to start?

      How can you tell how much muscle you gain?

      Is 2kg about 3.6 lbs?

      did you plateau before?

      How long did it take to get those results?

      For those of us that are not that smart, is fort night every 4th night?

  191. I’ve been researching IF and have found this site VERY helpful… however, there are many different approaches, and I’d like to get some suggestions on an easy way to ease into IF. Does anyone have any books they’d recommend to me? Thank you all for your wonderful posts!

  192. This gets really interesting when you combine the idea of IF and new research that shows certain bacteria in the gut are to blame for obesity and insulin dependency. Maybe a one-day fast works by starving and killing off the “obesity” bacteria.
    I suppose it might kill good bacteria too, so it might be a good idea to follow up with normal yoghurt (acidophilous) on the next normal eating day.

  193. I need to lose at least 50lbs and I am planning on working into IF fasting. What seems the best pattern for myself would be to eat a big evening meal and then work myself up to not eating until at least 1 or 2pm the next day. One question I have: I have a pacemaker/defib. implant. My heart is healthy except for the electrical. No blockages or any problems like that. But I still have been perscribed a low doseage beta-blocker twice a day. And because I have to eat something with it in the morning…what would you suggest I eat that wouldn’t upset my fast too much? It doesn’t take much.

  194. Personally, I would work my fast around your pacemaker needs at the least. You need your beta blockers in the AM,with food, that is when you should break your fast. However, with your situation, I would also discuss this with your doctor. You probably should keep a close eye on your electrolyte balances. These tend to drop when eating habits change.

  195. I fasted for 6 days the first time over 30 years ago but I didn’t do it right. Now I started fasting again but for only 24 hours once a week. I start with my last meal at 6PM on Thursday and start eating again on Friday at 6PM. I drink only water and as much water I feel that I need. I missed one week of fasting but I picked it up the next week. This is my 3rd. week at fasting. I plan to make it a way of life. I heard it was very healthy and also starting to eat more vegetables like apples and celery. I love it.

  196. A 24 hour fast isn’t when you have a final meal one night and then not eat until breakfast the day after the next.

    It is (for example) having your final meal at 7pm one night and not eating until 7pm the very next day – which isn’t difficult to do at all.

  197. Hey Mark,

    Your post on IF has enlightened me! I have been experiencing dizzy spells for the past couple of weeks and thought something was going wrong with my body. Now I know why! I was too lazy to pack a big lunch to work so I would constantly graze and the result was dizzy spells if I skipped a snack. I am definitely going to start practicing IF. Have a couple of questions!

    1. Can I skip lunch to start off with?
    2. What is the point of drinking coffee during a fast? Isn’t caffeine bad for the body?
    3.Can I have fresh fruit juice / raw veggie smoothie during that time?

    Appreciate your response.

  198. Hi everyone,

    Great article and comments! I just started the IF lifestyle one week ago and have been very happy with the results. I’ve lost 4 pounds in the first week. I have 7 more pounds until I reach my goal weight and although I intend to stick with IF most days of the week once I reach my goal, I will probably give it up on weekends.

    Here’s my one big concern and I haven’t been able to find a true answer to this question. Will fasting for 20 hours/day slow my metabolism? I worry that if I choose to give up the IF lifestyle that I’ll blow up like a whale. Does anyone know the answer?

    1. Wendy,

      Research shows the basal metabolic rate slows after 48-72 hours of fasting or very low calorie diets. This is the problem with juice “cleansing” fasts that last for 3 to 10 days. It’s just another yo-yo diet. You lose water weight and lean muscle mass quickly, but the water also comes back on quickly and the metabolic set point has been raised so the same amount of calories eaten before the juice fast now get squirreled away as fat since the body has learned to be more efficient with what comes in.

      There are human studies of intermittent fasting showing NO decrease in metabolism from 24 hour fasts. Lean muscle mass is also preserved. You can safely IF for 24 hours without concerns about negatively affecting your metabolic rate. I can provide references if you like – I have them.

      Best of luck with a healthy IF plan!

  199. IF has opened my eyes to metabolism. Wendy, you lost weight because your metabolism was kicked-up. We all fast so if IF causes a cessation in metabolism then we could not sleep or, as some suggest, stop eating at 7:00 PM.It is the fasting period, the time between dinner and breakfast, that I believe makes any diet work in the first place. Prolonging that period of time does not diminish metabolism. As a matter of fact I am planning to extend my fasts from time to time. I do IF everyday.

  200. I wasn’t sold on fasting but but I think I am now.

    I am 44 yrs old, about 275 lbs and 6 ft tall.

    I have lost dropped to about 207 in the past and then rebounded after about a year.

    I have recently started a hard regimen of cardio and weight training again, because I am so tired of wearing size 41 pants. When I am at 207lbs I was wearing 33s. any way after I started loosing it always seemed pretty easy to continue once I was in shape and I didn’t intend to fast but it seemed like I did it without trying I am not very hungry when I am running 3-5 miles 5 days a week. so I think in retrospect that I lost easier because I was fasting, it seemed I could almost feel myself loosing weight for 24 to 48 hours after the workout. especially when i would take a day off.

    I had always tried to maintain a low carb diet and eat many small meals a day but just didn’t have time. I was always worried I would start burning muscle when I didn’t eat regularly but never saw any sign of that. Now I am going to fast regularly and I am positive the pounds will fall away, especially since I quite smoking after a pack a day for 28 yrs and I am not drinking at all at least for the first 30-60 days, then just socially maybe once or twice a week.

    I love this site, I just came across it and it is very informative. I would love if other people would give their specific stories and make sure they give specifics ie; age, height, size etc. Thanks

  201. I am 5’10, male, weighed 219 when I started, about one month ago. Now, I weigh 112, am doing slim in 6 everyday with my class and have been thinking of fasting, because my body is kinda telling me due to growing up a runner and athlete. It wants to run. I did a 40 day master cleanser and dropped 40 pounds, I was running 3 miles a day, loved it. Gained all back because I did not know that my body was allergic to carbs, but now that I have found “The Secret” I want to do a water fast, about a week would be good, and fasting 2 days a week. I have noticed that my body does not need that much to eat, so in the future, I think I can eat one, 2 days off and my body would like that. Problem is (why I am posting) that I smoke, a lot. I have read that it is not a good idea to fast and smoke, but I have done so. I know that the master cleanser covered some of the effects of smoking during the fast, but with a water fast I know it will be different, so I must stop, and I figure that during my first 2 day fast this week, I can dump all the nicotine out of my body. Any hints as to how to deal when I get a nicotine itching?

    1. You know quitting smoking is very individual. You might try the gum. It is good for acute nicotine withdrawl onset. I’m not a doctor but when I stopped, it helped to imagine myself inside a coffin and never seeing anyone I loved again.
      Or hold think of when you get done sprinting and trying to catch your breath, now imagine if that feeling never went away like when you have late stage emphysema. That worked for me. My father died from Lung C. at 55 and I am 44 and recently felt short of breath just going up stairs. I guess there is nothing like fear of loosing your life to really make you think.
      Good luck and remember usually a cig craving only last for about 1-3 minutes at a time so what I do when I get one is drink green tea and after about 7 days the cravings come less and less. Plan on not putting yourself in situations that you would normally smoke for at least 2 weeks, the IF should help because one of my times was after a meal.

      GOOD luck 🙂

      1. It doesn’t matter when you do the 4 hours off IF, it is up to what works out for you.

  202. Sorry, to second post, I live abroad and am used to using K, so I started at 119 Kilos, now weigh 112 Kilos, need to get down to 100 Kilos before running, or even more, I will know when to run, when while walking my body will want to take off, my mind wants to do that, now.

  203. Hi Mark,

    Thanks for this great post. And, wow, what a load of comments!

    I for one am a big fan of intermittent fasting, but done as per recommendations given by Martin Berkhan at

    I find that I have more energy when I follow this protocol, I have lost fat AND gained muscle and strength over the last 3 months, very happy with that.

    I have just written a post about the potential benefits of Intermittent Fasting and the Ageing Process. I hope you or some of your readers find it interesting.

    Keep up the good work,

  204. I have struggled terribly with my weight since I was about 20 (now 53). I yo-yoed 40 to 80 pounds, year in year out, on every fad diet program that came out. I have lived my whole life being told that if I stopped eating I’d end up in an even deeper hole than I was already in. Then, on April 1st of 2010, I had an ah ha! moment. If you want to lose weight eat less. I know, to most, this doesn’t seem like a real epiphany but turning 52 and back up to 220 lbs what did I have to lose? I started eating 1700 calories day from 2 pm until 6 pm 7 days a week (20 hour fast). One year later I’m now 170 pounds and from size 42 to 34 pants. I do walk. I have been for the last 6 years my wife used a cattle prod for the first year to get me away from my desk and walking. Even that only helped me to maintain my weight rather than gain anymore. Not until I started fasting did the weight start dropping off dramatically. I was losing so quickly friends and family actually secretly asked my wife if I was sick. It’s now become a lifestyle. Amazingly, I am now one of those people I have envied all my life that can eat as much as they want of whatever they want. To prove my point I didn’t walk at all from November to March and gained just 2 pounds. If you’re(seriously) tired of being overweight do this! You’ve got nothing to lose but the fat. Right?
    Oh btw, fasting means water only, black coffee or tea, no juice. The moment you take in any calories (and juice is *loaded* with calories) you’re on a low calorie diet not a fast. Good luck!

  205. I started reading the first reply page and stopped after that. Seems to me that most of you that stumbled upon this blog are vegetarians?

    If you have to literally PLAN your IF then you’re not well nourished.
    I am so filled with nutrition that my hunger signals are completely turned off. Even the one for appatite…regardless if I smell the food or not.

    IF happens…automatically without you even noticing…when your body is so well nourished that it shuts the door for a certain amount of time on it own.

    I’m on a 80% carnivorous diet…no grains or legumes, no sugar, no juices ever, not even honey. If you have ANY kind of cravings before starting IF you’re not ready to starve. You’re missing minerals. When you force IF upon yourself for the sake of weightloss you’re depleting your mineral reserve = your bones.

    Good Luck to all playing the starvation game for vanity reasons.

  206. Your way of doing IF makes perfect sense and should be the goal of us all. But as for me, I have not achieved that yet. I do eat primarily animal protein so I am quite far from being a vegetarian. Your appetite is suppressed because your body is producing many ketones that make sure that nutrition is absorbed thoroughly.Ketones are natures method of maintaining, protecting and even strengthenin the human body which proves that there is no need to eat constantly. There is no need to diminish anyones method of doing IF nor why. I do it for health reasons and of course, I don’t want to turn out being as fat as my great grandmother. I have been doing this for 5 years so I know the benefits of IF.

    1. I am 44, working out really hard, alot of weight training and cardio every time i lift to start, usually 3 mile run or 3 min on the eliptical, then I hit the weights for about 5-6 sets of 3of 10 each supersetting without much resting.

      Anyway I am trying to loose weight I weigh 275 was, 285, and 6 ft tall I have been doing this hard for 4-5 weeks and eat a big fn salad everyday and if still hungry just protien like chicken. I am starting to loose weight took awhile because my muscles have been getting big again, like they used to be. My waist has lost about 4 inches but my question is I am starving some days and others not at all. but when I get done working out I am just shot, like I don’t have enough food energy. So I basically just try to eat in a 4 hour period everday and fast for 20 hours, any suggestions on what I should be doing?


      1. I would guess that you are almost certainly not getting enough nutrition from the amount you’re eating, especially on your training days, if you’re ending up shot once you’ve finished.

        If I remember rightly from reading Martin Berkhans site, he would recommend that you eat for an 8 hour block, and focus more on protein with your salad, especially post training, which if you’re doing a lot of you will be needing more protein. How many days a week are you training?

        Martin also recommends varying your calorie intake so that you eat more on the training days and less on the resting days. About 500cals either side of your BMR, if I remember right.
        See for more about Martin’s approach to I.F.

        I also remember something Lyle McDonald wrote on his site about not losing weight as quickly when calories are severely lacking AND doing lots of exercise. Check his site out, it really is superb.

        Hope this helps,

  207. Author: mory
    been fasting three days a week for three months– maybe lost a pound. on my eating days, it was maybe 1300 cals of very healthy foods. I run about 10 miles week. I’m about 190 at 5’4″ 34″ waist (rolly polly) very healthy, never get sick— just meant to be chubby I guess? before doing three days a week I was doing two for nine months– didn’t loose then either. I started two years ago with Tuesday fasts and daily 1200 cal days. over two years lost maybe 10 pounds? I’m close to 60, so maybe that’s it? people say I look early fortys, and that’s the way i feel— just thought by now I’d be.., maybe, 170?

    In response to this comment, I would guess that one of two things might be going on:
    1/ You’re not recording calories effectively and therefore eating more than you think you are.
    or 2/ You may be low thyroid, but borderline, in a way that normal docs tests wouldnt show up. You could read the work of Broda Barnes and do some baseline temperature tests, that’s what recommends, and you can also read this by Ray Peat;

    Either way, good luck

  208. H, I been working out everyday for the past 3 1/2 months without missing a day, counting calories no more that 1200 and i have successfully lost 33 pounds, but now my body is in total denial about lose any more weight the last month or so I haven’t be able to lose a pound, this is really frustrating, so reading all this about Intermittent Fasting that is new for me, I was wondering if you think is something that would jump start my weight loss? you think is what I should do at this point of my weight loss goal? I m planing on do 1 meal a day winch will be dinner around 5:30ish to 6? all my meals through the day are healthy, so should I consume my healthy 1200 cal in that hour, or should a lower the cal intake in that 1 a day meal? please help!!!! thank so much

  209. Here’s my experience: Fasting one day a week for two years, maybe lost one pant size. Started fasting two days a week, 9 months ago, have not lost much at all… Then at the end of Febuary of this year started fasting 3 days a week— think I’ve gained slightly over the last few months. I know my calories don’t exceed 8000 for the week. All i know, I feel great, little chubby, saving money.

  210. You can lose weight on IF, but I would not begin IF to kick up weightloss. You might be dissapointed.I wanted to lose 10 lbs the first year of doing IF. I not only lost 10 lbs…I lost 12 lbs. It took the entire year and I was fine with that. But I find many people are not happy with losing so little over such a long period of time. I was happy with my results and I continue doing IF even though my weightloss eventually slowed.Fasting will not cause you to drop a lot of weight unless you do it for a long time. Be willing to do it and yes, you just might lose a little weight.

    1. I’m so glad to hear this. I, also have not lost allot, and so many have– which rasied the possibility of thyroid issues… I think I lose about a pound a month too. I am now fasting Monday and Tuesday, eating Wednesday, and fasting again Thursdays. 3 days a week for at least 3 months now; love the psychological and physiological aspects, but was surprised that I didn’t lose. Although, it feels like I lost a tiny bit over the last few months, but three days a week, and maybe a couple of pounds!! this kinda shocked me. I should be about 20 pounds lighter– so maybe a few years down the road? In the end, it doesn’t matter, I’m feeling good and NOT GAINING!

  211. I have been fasting twice a week for 24 hour periods and trying to restrict my daily calorie intake to between 1200-1600 a day in between. If I know I am going out to eat in the city and having a huge meal with an appetizer and desert I prepare for that by having that be my only meal for the day cause its easy to pack away 1200 calories in that one meal when you do that. I started last June and now its going on a year later. I was 215lbs and now I am 154. Lean, Abs and the thinnest I have ever been and all of my lower back pain I used to get now and then, is GONE!:) Never have it anymore. The beauty is, I hardly ever workout except pushups and pullups every week or couple of weeks. Gonna start hitting the gym again though when my schedule slows down which will be in September. Good luck everyone. It WORKS!! I have been on every diet and had results with them all but not like this.

    1. This is what I do. Today is our anniversary and I plan to eat like a fool but not until our “date” tonight. I have been trying to do a little lifting but that is it. I hate exercise but my body needs it.

  212. Just remember NOT to fast right after an intense workout and do give your body a chance to recover completely before start on a fasting program.

    I agree with some of the users in here that drinking juice on a short fast is NOT ideal since your body will think you are on a low calorie-diet instead of really fasting.

    I fast on water/herb teas once a week on a Sunday for 24 hours starting after lunch until noon on Monday. Again, the reason for Sunday since it is a quiet day for me and I have done my intense workout during the week, which my body completely recovered by then.

    I alternated between drinking hot water with lemon and herb teas throughout the day. The kind of herb teas I drink are detox teas like kidney cleanse, liver cleanse, artichoke leaves etc.

    I break my fast with a vegetarian protein shake, which consist of two tablespoons of organic brown rice sprouted powder (85% protein digestibility), two cups of coconut milk, one tablespoon of wheat grass, a large ripe banana or pear and a handful of baby spinach.

    Cheers from Karl 🙂

  213. I just got done watching a tv show about two docs in the jungle in africa to see how they used plants as medicine. What was amazing to me is on the days they didn’t get an alligator, they ate honey combs and veggies. I think back then there was more honey bee’s in the wild than what we think today. And those guys were ripped. So yes I fast 16/8 my self but on some days I am going to try this and eat raw honey comb and veggies a couple times a week and see where it takes me. Think about it even in ancient times they did drink a lot of mead and that takes quiet a bit of honey. Something to think about

  214. IF has been an amazing lifestyle change for me. I have an interest in building muscle so I used to be one of those people who was obsessed with getting protein every 2-3 hours.

    With IF, it is so liberating to not have to constantly think of food!

  215. hi I am a 16 year old high school student. I wonder if IF works for adolescents in the middle of puberty? Or do I have to dine three times a day to assure maximum growth?

  216. Do you believe in the mitochondrial hormesis concept, which, as I understand it, basically suggests that by subjecting your body to great oxidative stress caused by fasting that your body adapts by better tolerating and dealing with exogenous radicals and other toxic compounds?

  217. Damdam, Once upon a time fasting was a part of every diet. It remains a part of today’s diet actually which is where the word “breakfast” comes from. The most important meal for breaking your fast is indeed breakfast but when you break that fast is totally up to you. I encourage everyone not to drastically change your eating plans. Instead coast into fasting by eating dinner a little earlier and/or eat breakfast a little later. Do this slowly on a day by day , week-by-week- and month-by-month basis until you can easily eat once or twice a day. If your diet is rich in protein and other nutrients such as B vitamins, magnesium, healthy unadulterated fats, vitamin D, there should be no reason why a healthy adolescent can’t do intermittent fasting. I strongly believe that in order to have a healthy fast you must primarily have a healthy diet. Your last meal of the day should be rich in foods that help stabilze blood glucose such as chicken, seafood, pot roast, flounder, lamb, organ meats.Most vegetables are low in carbohydrates and good choices are turnip greens, kale, collard greens,spinach, turnip roots,asparagus, artichoke hearts, summer squashes. On days when you feel that you need more vegeatbles remember your vegetable juice. Check the contents label for carb content and choose the juice with the lowest carb content. Make sure that you use butter, cream, olive oil, coconut oil liberally and without fear. Some fruits to consider are raspberry, blackberries, strawberries, bell peppers of all colors, tomatoes, avocadoes, cantalope, grapfruit. Honestly, I wish my diet as an adolescent were this healthy.

  218. This diet is just too convenient to quit…

    I’m 7% body fat all year round.

  219. Funny… this blog is ABOUT fasting not whether a fruit will kill you or not, which it doesn’t by the way.

    I fast once a week on a Sunday since it is my quiet day and I do my enema at the same time, which gives a total detox experience.

    Been doing this routine for the last 3 years and I am still at 9% body fat.

    1. I fast Monday, Tuesday (tuesday– wow, my finest day) eat light on Wednesday, fast Thursday, eat “aveage american diet” on Friday Sat, and Sun. I take 10 grams of powdered Vit C/Mag in a glass of orange juice in lieu of enema. For those that love that “cleaned out GI” feeling, mega dose of Vit C is an incredible alternative. not only cleans you out but so many more incredible benefits– not the least of which is anti-inflammation.

  220. Funny… This blog is about fasting NOT whether a fruit will kill you or not, which it doesn’t by the way.

    I fast once a week on Sunday because it is my quiet day and do the enema at the same time, for a total detox experience.

    I simply drink Peppermint, Milk Thistle and Yerba Mate teas all day.

    I’m still at 9% body fat for the last 3 years without breaking a sweat.

  221. I started doing this about 5 months ago. My weight at the time was about 250 pounds. Depressed and unhappy I made this simple move to ADF and it changed my life. In that time have dropped to 198lbs, I look younger and feel like a million bucks. I follow a strict ADF 24hr eat 24hr fast.
    Mon Eat Breakfast, Lunch and dinner
    Tues Miss breakfast Miss Lunch Eat dinner
    Wed Eat Breakfast, Lunch and dinner.
    The best part is that I start end my fast at night so I always get to eat dinner. On the eat days I eat until I feel 100% full and never feel like I am eating on a diet. Note food intake is nothing processed and a meat and veggie diet, on fast days only water. I never fast more than 24hrs. I have done tons of things but this is the one sure fire method for losing weight. My brother is pushing 400lbs and he just started this program too. I cant wait to see his results. Best of luck to anyone trying this and making it part of their life.

  222. Congratulations Scott, That is wonderful. May I ask what kind of foods do you eat when you break your fasts?

    1. Anything but pre-pkg food no soda no fried food. However I do go out to eat and cheat once in a while. I enjoy eating as we all should and when I eat I make something that will provide energy for my next fast period. I love sushi and eat out twice a week for that! Good luck.

  223. I’d like an opinion…. I’ve been fasting about 90 hours a week– Monday, Tuesday, eat Wednesday, fast Thursday- then eat through Sunday evening. Been doing that for 6 months; I’m very comfortable in this schedule– look forward to my fast days and the energy it brings. But recently, I’ve been reading that Glucagon reaches it’s peak at about 60 hours, and concomitantly, the peak of growth hormone. so…, 90 hours is over kill– right? I’m thinking of just going for a straight 60 hours and doing it all in one fell swoop– Sunday night TO Wednesday evening, eating normal the rest of the week. Does anyone have experience with this, or know which of these plans would bring better health?

  224. I’ve been practicing IF for 6 weeks. I do 16 hour fast on a few days a week (if I don’t feel like breakfast) and do 20-24 hour fasts twice a week. I also eat primal blueprint. I do 40mins HIIT daily plus weight training alternate days. I have a cheat day once a week where I usually stick to lower carb.
    I’ve lost 23lbs in 6 weeks.

  225. I started out with a combination of two types of intermittent fasting: 1. Eating all of my meals for the day within a 8-9 hour period. 2.A total fast for a 24 hr period once a week. I dropped fat fast and find it very easy to take weight off when I put on a couple pounds after a less scheduled weekend of eating. Now I primarily do one 24 hr fast a week and skip breakfast with the occasional 250 cal post workout shake to maintain leaness below 10% bodyfat and still eat fun food. I agree that it is such a relief not worry about eating every 3 hrs and I’m much less of a slave to food.

  226. IS there a difference of how the weekly fasting effects you if you younger like 15, if you skinny or fat?

  227. ME and my friend want to do an experiment of our own on the subjected, does anyone know any experts we could talk to?

    1. Hi Ryan,

      You can judge for yourself whether I’m an expert, but feel free to email me via my website if you want to tall experimental with me.


  228. i need someone who went to school for the subject so i can prove to my teacher there an expert, so if you did id love talk to you

  229. Hi everytime i IF the inside of my lips and gums peel and can pick bits of skin off. Anyone else have this or anyone know how to stop it happening?


  230. Mark,
    What you explained about your 79 year old friend. He actually is fasting longer than 24 hours.

    I found that fasting that way sometimes made it hard thinking I was not going to eat ALL day.

    One thing that I came across years ago that I like is a true 24 hour fast.
    The difference with it is you could start at any time that worked for you. So if normally my 1st meal was at 6 am. I would eat every 2-3 hrs (6,9,noon,2). Then I would stop from 2pm -2pm the following day. The following day I would eat 2pm, 5, and 8. So I fast for 24 hours but actually get to eat both days.

  231. I am a bit confused, because I thought the IF was an Intermittent Fast. It seems that if people are fasting every day, or every other day, it’s not really intermittent? Practically speaking, would you then not be just getting your body accustomed to a lower caloric and nutrient intake, rather than mimicking the feast and famine concept of our ancestors…sometimes food is readily available and even abundant, and other time food is scarce?

    I know that if you find your body composition goals plateauing, a good way to notch up your leptin response is to have a feasting day followed by a fasting day…intermittently. Not all the time! By operating at a calorie deficit for as little as 6 to 8 days, I have read that the levels of leptin can drop up to 50%. Then it would make sense that your body is in famine mode, releasing cortisol under the stress caused and resulting in more fat storage. So if you feast for a day, say one day a week or two and then fast the next day, it sends a different message to your body- that food IS readily available and your leptin levels increase. After say, 12 hours of eating more, then you fast for the next 24, which puts you into a caloric deficite right when the leptin levels have increased, thus signalling to your body to burn available fat stores…because you have just revved up your metabolism by eating. Then the rest of the time, you eat your normal 1800-2000 calories a day ( or whatever is normal for you based on activity levels) and of course, keeping up with a Primal way of eating.

    I can see how the body will continue to lose weight by fasting…but should we not also be concerned with taking in appropriate micronutrients on most days? I look at eating Primal as a way to really boost my micronutrient intake naturally, without excessive supplementation. If the discussion is IF, then doing it every day does not seem….intermittent!

    I am curious to see the responses I get to this!

  232. I’m not sure if this has been mentioned, and it may be a bit technical, but here goes. I keep hearing people referencing a fast for “24 hours” and then they eat dinner one night and nothing until breakfast two days later. That’s probably closer to 32 hours. If you want to fast for 24, as I have tried with good results, you can eat dinner one night, and then dinner again the following night. Assuming you eat at the same time – those are 24 hours apart. I’ve found that is actually fairly easy to do, possible sneaking some nuts or soybean seeds if I really get hungry during the day.

  233. II am doing Paleo and only eat about every 4 or 5 hours and eat three meals a day with my last meal around 5pm. I am never hungry between meals anymore.
    Is it possible to just skip a meal for a fast? Would that be even close to being effective???

  234. Let me get this straight,

    1) Fasting causes increased insulin sensitivity.

    2) Eating a lot causes decreased insulin sensitivity.

    So if we keep fasting once in a while, in the context of not binging during days with food, then we improve our insulin sensitivity, which would allow our bodily cells (including adipose cells) to be more responsive to insulin.

    Therefore, we will get fat once we do this because our fat cells are more sensitive to insulin, and is able to uptake more glucose?

    Confused. How is this going to help promote fat-loss and prevent muscle-loss?

  235. By accident I did a 23 hour fast and found it to be not a bad experience at all. I had breakfast and then didn’t have a chance to eat dinner. I felt so good doing this that I decided to try doing it once a week.

    On my fast days I eat an all-meat breakfast (1 egg, 1 beef patty and bacon the last time). Then I do not eat until breakfast the following day. I feel great, alert, strong, energetic and mentally calm. Now I can go to my evening jam session and jam all night without worrying about getting home to make dinner.

    Peter I think this promotes fat-loss and prevents muscle-loss because you are still eating every day. You aren’t starving. You are simply increasing the window of not eating which allows other hormones in your system to do their thing. I think it is part of the process of improving your metabolic flexibility, something lost eating the SAD with frequent feeding times.

  236. Our fat cells will become more sensitive to glucose which will keep the insulin levels steady. We won’t need to consume so much food that floods our system with glucose. Just enough to keep the insulin stable. Now that I have been fasting, my glucose levels stay within the 75-97 range.

  237. I have been vegetarian since 94 and vegan since 04. I have always stuck with 5-6 small meals a day and done well. If I waited longer I would start getting a headache, telling me I need to eat. Recently I stared the Candida Diet mainly to support my wife who really needed to. In the process I found out that I literally had a wheat addiction that would cause headaches if my levels got low. Since kicking wheat (and corn and sugar) when I get hungry I don’t get a headache any longer. This has enabled me to fast for 24 hours with little discomfort and actually enjoy the sensation of calorie restriction. I plan to soon begin an IF program using the daily 16 hr fast, 8 hr eat method and include a basic muscle building routine. Wish me luck!

  238. Good article Mark.

    I have at least 8 years coaching people using IF methods and have found a 12-14 hour fast to be ideal in most fat loss situations. Given this I have my clients do a 3 day system where they eat a large meal mid-morning and another late at night. The next day they eat between 1-4pm and have only water the rest of the day and day 3 mirrors day 1. It’s worked quite well at breaking plateaus in my weight loss clients over the years and I continue to use it today.

    On another note one area I am extremely interested in but see little research on is the idea of food batching. It seems to me that ancient man grew, found or killed something and probably munched on that food or few foods until they were gone or nearly gone. So, if fish are prevalent this week, we catch a bunch and eat tons of fish….then they leave. Next week berries are ripe and we kill a deer so we eat berries and deer for 18 days straight before we catch a wild pig and find some nuts which may last us a couple of weeks. I’ve played with this a bit on my own eating just 3 foods each day for up to 2 weeks before changing foods and beyond being really boring, I actually felt pretty damn good. Thoughts on this concept?

    1. Jared, as to your comment on food batching. It makes lots of sense to me. I don’t do food batching, as you describe, but I do find myself eating the same thing for days without becoming sick of it. When I do become sick of anything I eat, I quit eating it. I eat once a day, now.

  239. I am a wrestler and in my fasting experience i had to drop about 7 pounds and still be hydrated to be able to wrestle at a certain weight. I did a fast starting Monday night and ending Tuesday night. When i woke up in the morning 1 weighed 154 lbs. All day i drank water and ate nothing. I then weighed 150 lbs so i still had to drop 5 lbs so i ran with lots of sweatshirts and sweats on. I got all the way down to 142 lbs in less than a hour.i then drank 3 pounds of water to make sure i was hydrated. i took the hydration test and passed and weighed in at 145 lbs. After that day my natural weight was 148 lbs by eating and drinking anything i wanted to. Fasting helped me lose weight quickly and keep it off!

  240. Quick question…
    Water whilst IFing obviously great – still or sparkling. But is coffee ok too? Black coffee? Seems too good to be true!

  241. Read “How to Eat to Live” by Elijah Muhammad this book was written in the 60’s. He talks about fasting for 24 to 48 hours and how eating this way will prolong your life.

  242. Thank you for making this post.

    Actually, as a Muslim, fast is obligatory during 30 days at a certain period of the year, from dawn to sunset.

    I did not know about the finding you mentionned in your post about the benefits of fasting. However, I think that not eating for a good period could help better appreciate the food that one has.

    Moreover, if a person is fasting for the Ramadan for example, it helps to avoid eating whenever you feel hungry (except after the set time for breaking the fast). Thus, there is an element of self control.

    Thank you for sharing these data.

  243. I fast from 11pm-1pm daily. It is working wonders for me. Energy through the roof, gaining strength, burning fat, always in a good mood and caloric management has become a breeze. Counting calories is practically pointless. Quite difficult to eat too many calories in the small 10 hour window.

  244. My experience: Since cutting sugar out of my diet, for the most part several years ago, I naturally started skipping breakfasts and kept weight I had lost – off. Giving in to the idea that it is important to eat breakfast saw me gaining weight back. So I skip breakfast most days. (Sometimes I do eat breakfast, but it is usually when I know I won’t have access to good food for most of the day.) My habit for the most part is to go from 7pm to about 11am to 1pm without eating. That is 16 to 18 hours. This is before learning about primal/paleo eating.

    Although, I still have a few pounds to loose, most people don’t believe that I am 50 years old. I look and feel healthy!

  245. I don’t know if this has been mentioned already. THis is TMI, I know but it is very significant. My bowel movements have improved immensely. I ‘go” regularly everyday. I empty my gut about an after after my fast-breaking meal. I sometimes “go” even twice on some days. Nothing is healthier than regular BMs.

  246. I haven’t found that working out on an empty stomach leads to inability to build/maintain muscle mass.

    I am 39 and have never really had much muscle on me (6’2″ and 185 lbs with a little bit more body fat than I would like).

    Anyway, I started doing CrossFit only 2 months ago and because of our family schedule, the only time I could fit the workouts in are at 5:45am. Waking up at 5:15am I just can’t bring myself to eat breakfast before my workouts. I take a 300-ish calorie recovery drink of honey, whey protein, and water right after the workout and that leaves me feeling like I don’t WANT breakfast so I tend to not have it (which is a departure from my typical behavior because all my life I’ve been a “breakfast is the most important meal fo the day” guy).

    Anyway — I’m not huge but the muscle gains are pretty dramatic. Overall I get lots of protein daily (100g – 200g), typically closer to 200. This leads me to believe that it’s not really that important to eat before working out.

    With that said, CrossFit is pretty intense and I’m fine for 90%+ of the workouts. When a timed workout includes deadlifts at 90% of max weight, as an example, I can sometimes feel lightheaded, which I attribute to my empty stomach.

    That’s my experience with working out on empty.

  247. Kevin I would wager, seriously wager that, you build healthier muscles while fasting. Weight training enhances the production of growth hormone during the fasting period. Remember fasting is not STARVING. Fasting produces other agents to strengthen not weaken the body. These agents, ketones, protect muscles and other cells as they enhance the production of glucagon and human growth hormone.

    1. Funny…I stumbled on to this yesterday..been trying to lose weight had hit a plateau after CR for a few months.. I use to lose weight more easliy..I am almost 43 now… My old habit was not eating breakfast sometimes lunch..not usually big and then whatever I wanted for dinner.. kinda sounds like I was doing the IF w/o realizing it…then I read how important breakfast was figured I was getting older and it would be better to eat a good breakfast blah blah blah…Gonna go back to not eating breakfast and trying the IF…I like the idea of having a eating window..that way if I am hungry for something or craving something I can tell myself..YOU CAN HAVE IT just be patient! Plus I can eat hearty with my family!!

  248. This seems to be a great way to manage my health, I have done intermittent fasting for now two years, a random day over a twenty four hour period, at least once a week, then let a month past after three months, and back into the process , I also have light calorie days, intermittently , which appears to be giving me the energy I need, and when I refer to detox I only eat quality proteins and my Crabs come for fruit nuts and grains no proceed foods, and fluids mainly filtered water, this also improves my pallet. I find what work for one may not work for another and it’s a process of experiment , this type of process I don’t believe will harm the body, if they’re not done for extended periods of time, but improve general health and allow the body to repair.

  249. Glad to see it’s got your approval of all people in the industry!

    I’ve incorporated the 16/8 intermittent fasting hours with a lot of what I’ve read in your blog and book. Ferociously lean and feel great.

  250. I am LDS so, as part of my religious beliefs, the first Sunday of every month, from the time I was about 8, I generally have been fasting from all food and liquids for 24 hours -(except for special health circumstances, illness, pregnancy etc.)
    In my late 20’S, for about 3 months, I fasted every week for personal spiritual reasons, not thinking much about health issues. But I did experience health benefits. I slowly dropped pounds and felt better generally.
    Recently, the idea of Alternate-day Fasting was introduced to me through the book “The 17 day diet.” I was intrigued and decided to do an experiment for one week, only drinking lots of water and taking a fish oil supplement in the morning and evening on the fast days, unless I saw any negative side-effects.
    I was so impressed with the results! I lost 4 pounds. My energy level sky-rocketed, and my food cravings decreased. On the food days, I actually ate less than normal because I didn’t feel like eating more, naturally. My blood-sugar seemed to be much more stable and I felt as if my body was “resetting” itself to my childhood eating habits… which were way better than my adult eating habits! The first day was difficult, but each fast day after got easier. And my regular Sunday fast, which fell on the following alternate fast day was a breeze! I actually experienced too much energy! I felt so good inside. The only downside was a bit of constipation, which can be easily fixed with the right kinds of veggies on the food days, I think.
    The following week I followed phase I of the 17 Day Diet and it was so much easier than the last time. Amazingly, though, Doing ADF was actually easier than doing phase I of the 17 Day Diet. I prefer it. I am starting again this week!
    Thanks for sharing all the great experiences!

    TJ King

  251. T.J. King, I am very appreciative of your story. IF does change your appetite more to how we ate as children.As children we had to be reminded to come in for dinner. We always had to be bribed, with dessert, to clear our plate. This is why I tell people it is impossible to overeat on IF. If you want to gorge yourself on food, that is okay becaue you won’t feel that way on your next meal.

  252. Not complaining— just an unusual reaction to IF. I’ve fasted 3 days a week for almost two years– no weight loss. But I feel great, have all the other benefits of fasting— I’m 190 and at 5’4″ — 57 years old…. I also think I’m younger looking than when I started. Face has thinned, but my stomach is still a 36″, tons of energy,never get sick, sleep wonderful… I don’t know, maybe I’m supposed to be chubby??

    1. It may take a year before you notice any loss. IF helps with weightloss but it doesn’t make you lose weight. When I first began IFing, It didn’t seem like I was losing although I was gaining either. But as the year ended, I lost more weight than I had planned on losing, which was a good thing.

      1. Thanks for your input, Mary… Your experience may be whats happening to me. I mean, I haven’t lost weight where people notice, but in the two years I’ve been doing this I have not gained, and maybe slightly lost (especially in my face) when I did weight watchers with my wife I lost 50 pounds in 6 months! but of course, can’t count points for a life time– but I can fast for a life time!

  253. Recently read Brad Pilon’s 5th edition of Eat Stop Eat (downloadable ebook). He makes the pretty strong assertion that after you improve the quality of your food intake etc, you can still maintain a chunkier physique (even whilst getting the great autophagy / improved health)from Intermittent Fasting. If you want to lose weight, you have to find a sustainable way of reducing your calorie intake lifelong – we are in a struggle with an environment awash in calorie abundance, when we evolved to thrive in an evironment with a substantial amount of variance in calories available (hunting and gathering might be good or poor). IF is a way of restoring some of that Yin/Yang plenty/lack variability in a straightforward way….but it is easy to have too many calories still!

  254. All of you people who say long fasts are “dangerous” and that it can’t be done, really mean YOU can’t do it because your will or intelligence is too weak. My longest is 44 days of only water and a limited amount if vitamins. The entire time; including my 44th day, I felt amazing! Tons of energy, strength, clarity, and sense of well being. Quit imposing your mythological misunderstandings and personal weakness on others. In general, educate your self or keep your mouth shut.

    1. You know, I’d have to agree. I’ve only fasted one week as my longest fast.., and of course, at some point you’d have to die. But, I did have so much energy and mental clarity after a week– it just made me think the need for food is way over-blown. on my my regular, twice weekly 42 hour fasts I always have more energy and clarity the second day, and bog myself down on my eating days; after a week it was amazing!

  255. If I can find the link, there is a link that discusses how diabetic [atients were once treated with a 2 week fast as a way to cure their diabetes,,,back in the day>>>

  256. I am currently fasting from 7pm – around 2pm the next day. I train normally at about 11am or 12pm. I will take free form amino acids pre and post workout. My energy has been increased and I am sleeping better. I am going to start juggling my fasts with no structure. Some days I may go 16 hours, others days 24hrs and then other days not at all and eat as much as I want. I think shocking your body through different eating volumes and frequencies is just as important as mixing up your training regime for improved results. Thanks for the post.

  257. I’m the kind of person that likes to have my cake and eat it too…and apparently the cake has been winning because I have not dropped my baby weight and my youngest is 6 :). I don’t remember how I came upon the routine I’ve been using for the past few months, but I’ve been averaging about a 1 lb. weight loss every week since I started.

    I like the idea of cutting out processed foods, but I also have a tendency to drool over things that I know are not good for me. So, this is what I do.

    Weigh-ins are reserved for Friday mornings (mainly because I know what I’ll be doing Friday, Saturday and Sunday; which would make a Monday morning weigh-in just dumb). You know the saying, ‘the diet starts Monday’! Starting Monday morning through Wednesday supper I eat Paleo, minus a chocolate craving here and there. Then I fast until breakfast on Friday, with the exception of my morning coffee. Some things just can not be interrupted.

    I find that my energy consistently increases throughout the week, and then I get the good news of the weigh in on Friday and I feel great going into the weekend. I eat and drink to my hearts content all weekend until I’m literally saturated and looking forward to Monday morning when I can stop the madness and begin to clear out all my ‘food and beverage sins’ once more.

    This may sound like a massive roller coaster, but I’ve found that it is the true key to my nourishment happiness AND I am finally getting rid of my baby fat. I LOVE IT!

    I’ll end it here, since there really isn’t anything going on in the way of an exercise program. I’m assuming I will get there and will finally get to one day parade around in a bikini again, but for now I’m enjoying the fact that my joints no longer hurt and I am regaining mental clarity and guilt free eating!

    I didn’t even know it was called ‘intermittent fasting’ until I realized I was on to something and decided to search the internet.

    Happy Fasting! (and eating).

  258. Ah, fasting. What can I say? When I first started it, I was a bit wary. Sure, I had heard all the industry tag-lines and “Sacred screed,” so to speak, and was giving it a second thought. But one day, out of necessity, I didn’t eat for over 36 hours—and let me tell you, after a life of cheeseburgers, shakes, fries, and all the other good American fare, feeling over-fed all the time and wondering why I was so tired, basically living a totally self-indulgent non-life, the 36 hrs I did weren’t so hard, and at the end of them, I actually felt….well, great! I had some energy, actually slept better than I had in a while, and so forth. Intrigued, I started to do some internet studies on giving up food, since I just felt so fantastic after not eating or a day. And I was happy to see there was some research and experiencce based info out there–so, I can now say, with certainty, after trying to be pretty regular at intermittent fasting, I find that I do not miss the food a bit, and feel really great on days when I do eat. Maybe I will get to where I am eating once every two days, instead. Definitely worth a try if you’re sick and tired of being sick and tired. Thank you for reading.

  259. In memoriam, Master Kwai Chang Caine
    died June 3, 2009
    Follow the endless highway, and find the Pacific coast…touch its water…and be free…..
    Marv, DHAF

  260. Hi Brad;This isnt really about this post but I weantd to ask you some questions. I have just discovered Intermittent Fasting/Eat Stop Eat and have downloaded your Elimination Exercise thing but weantd some advice on what Compound Exercises are best?? Im not a fitness expert so can get a little confused about what everything means!! In your PDF, you didnt mention anything about compound Abs exercises, unless the abs are dealt with in one of the exercises you mention. Anwyay, some hints as to what compound exercises would work everything including Abs that would be great! (in lay man’s terms too if you can !)ThanksLou

  261. There are SO many “specialists” and theories out there as to what is best for us and I believe this is just one of many, too many, and it flies in the face of what we have been taught which is that going without eating for a prolonged period of time will slow the metabolism, one the main causes of obesity. For me, my sleep deprivation is kicking my ass and ruining my health and attempts at losing more weight. This plateau is frustrating me cause more stress which causes more cortisol which causes more belly fat, and so on and so on…:-(

  262. Anybody out there female, middle-aged, menopausal? I’ve been doing IF for about a month now, and have tried several permutations — 2 consec days/wk; two split days/wk, 3 split days/wk — and half lost 1/2 stone (7lbs). I also workout 4 hours a wk, including interval training, free weights and calisthenics. I’ve noticed astounding muscle gain (it really IS remarkable!), but last week I had a hormonal meltdown. Like PMSx400%. Severe seratonin drop; felt suicidal, weak — high cortisol, extremely irritable , and massive migraine. Although the headache has now receded and I’ve recovered from the emotional drop, I remain extremely fatigued. Any ideas from anyone? Should I stop? What might be causing this? Should I go on with modifications? If so, what sort? Any ideas welcome.

  263. From me, I have been doing IF for 5 years. I am 55 now. Firstly, I must remind you that IF is something new to your body, it needs time to adapt. IF is a sudden change and your body will protest this torture. When I began IF, I did it gradually.I began by eating breakfast gradually later in the day. So if I ate breakfast at 6:00 AM for a few days, then I increased that to 8:00 or 9:00. Then I went to 11:00. It was exciting to go to noon without thinking about eating. Eventually I was able to go to 3:00 P.M. before having my first meal of the day. Now, I break my fast anytime after 3:00. I honestly try to think like a cave woman when it comes to fasting. I thing the fast-breaking meal should prepare you for your next fast, not releive you of a fast. In other words, you have no idea when or where your next meal will be. so eat heartily and eat food that will stabilize your blood glucose so that you can carry on during your fasting. That means eat plenty of well nourished protein ( grassfed whenever possible ).Healthy colorful veggies especially green leafy ones. Migraines may be a very strong sign of magnesium deficiency. This is very common in everyone ESPECIALLY pre and post menopausal women. I prefer supplements. bath salts and magnesium oil ( applied topically )to eleviate these symptoms. Have your vitamin D levels checked and make sure that they are on the higher end of the range not the lower end or borderline.

    So basically back up from what you have been doing. Review your diet and consider what you might add or take away from the dietary equation. Are you eating enough when you break your fast? Also when you break your fast, are you eating enough to carry you through the next foodless hours that you will be experiencing. Are you eating enough fat,water and sodium that is so very important.End each day in a nice soothing 20 minute soak in a tub of magnesiums salts…sleep like a baby.

  264. Spot on with this write-up, I seriously think this web site needs much more
    attention. I’ll probably be returning to read through more, thanks for the info!

  265. May I simply just say what a comfort to find an individual who
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  266. Just curious… any long time members still doing IF?

    Or, have you stopped?

  267. been fasting 3 days a week for quite a few years now— haven’t lost much weight but so many physiological issues of age have disappeared or have been muted. I look younger today than I did 5 years ago, and feel like I did in my early 40’s– I’m almost 60. I struggled my whole life with being over weight (300 at one point– and I’m only 5’4″) In the 5 years I’ve been fasting, I might have lost about 10 pounds and weigh about 190 right now. on non-fasting days I can’t over-eat, my stomach has shrunk. Food used to seem so much more important to me; it’s not that it tastes bad, it just doesn’t taste as great…, funny….

  268. Interesting thead. One commenter alluded to “dry” fasting – no water. Can’t say that that sounds like a good idea.

    I liked Mark’s summary. He shifted from thinking he had to fuel his body every couple of hours to being ok if he skipped a meal every now and then. That approach works for me as well. I go most of the day without eating one or two days a week and the other days have 5 or 6 meals consisting of protein and vegetables most of the time. It’s helped both my energy levels and my ability to stay lean.

  269. Hi everyone,
    Dr. Thomas Seyfried Ph.D. is using the Ketogenic Diet and IF to reverse Brain Tumors in mice, and the studies are heading to humans. He believes Cancer is a Metabolic Disease, and cutting out carbs (sugar) and oxygen chamber usage, have major promise in C treatment (tumor types).

    Otto Warburg won the Nobel Prize in Medicine in 1931, and Dr. Seyfried is continuing his hypothesis work.

    IF converts a glucose energy body into a ketosis body for energy, and is actually good for you. I’m doing a 5 day IF to get into Ketosis faster.

  270. “Intermittent fasting has also been shown to reduce spontaneous cancers in animal studies, which could be due to a decrease in oxidative damage or an increase in immune response.”

    …or yet, maybe the non-cancerous cells end up accidentally “starving” the cancerous cells. Perhaps the cancerous cells benefit from a nutritional surplus that is reduced by means of fasting/smaller nutritional intake, or higher demand from healthy tissues (it seems that exercise also slows down cancer in rats or mice, specially if combined with the consumption of caffeine).

  271. “And it all makes sense from an evolutionary perspective”

    What tires me the most is this just-so-story evolutionary/hyper-adaptationist reasoning. There’s very few imaginable things that wouldn’t make any sense at all under a realistic evolutionary perspective, simply because most/many organisms are considerably ecologically generalists, not being strictly adapted to a narrow set of environmental conditions, but able to deal with a reasonable degree of changes.

    Environmental changes won’t necessarily drive specific adaptations (like hibernation) to “cycles” or “patterns” like times where food is plenty versus scarce, but by the mere fact that an organism that is adapted to “enough” food is simply not certain to go extinct if the food sources become more abundant (population will probably increase, but probably rarely/almost never before there were situations where obesity was an issue) or become more scarce (population will decrease, and physical conditioning of individuals will suffer heterogeneously through the population and lifetime of individuals).

    Besides that, and also of critical importance, the “evolutionary environment”, to which most of the current adaptations of an organism evolved, isn’t necessarily the best environment for the organism — it’s the other way around, the organism became adapted to the hurdles of the environment! That’s why there are things like “pests” through invasive species and higher-taxon selective sweeps. Sometimes species that evolved in an environment, adapted to it, are unable to compete with a newcomer that is just accidentally better adapted to that environment, perhaps because it was adapted to an even harsher one, or just has some specific adaptation that isn’t product of an overall harsher situation, but gives it an winning edge anyway.

    To sum things up, even though our bodies are products of evolution, and it can be useful to take that in consideration, we shouldn’t expect a narrow adaptionist outlook to be a reliable guide in discoveries or theories. It’s to be expected that evolution results also in accidental byproducts of several adaptations (or even maladaptations), and these byproducts can imply in better health outcomes for situations that have little to do with replications of the latest range of African environments that our lineage endured. There probably never were a cultural adaptive peak at an “original human condition”, the original humans using the human body at the optimal level. That’s not even a reasonable expectation from the theory of evolution, it’s more like BS one will hear in sci fi stories of Star Trek and the like. And here I am, arguing at length with the internets again. Another evolutionary maladaptation, for sure.

  272. That is a great tip particularly to those fresh to the
    blogosphere. Brief but very precise information… Appreciate your sharing this
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  273. That’s why, Clarine, it is important to review various publications on the subject as well as discuss it with people who have done it for a long time. I only say tat because there are very trustworthy articles on ths subject, this is not the only one. AMD there are people who do this that can support that data here. Good point.

  274. As a Muslim, I have to fast from sunrise till sunset for 29 to 30 days a year (during the Arabic month of Ramadan), except on menstruation days (and these have to be compensated some other time of the year). It is also “bonus” to add Mondays and Thursdays on any time of the year. Other “bonus” days are the three full-moon nights in the middle of Arabic months (which are lunar months).

  275. I have been taking ACV and ginger tea plus IF for about two months for diabetes 2, with incredible results, but have lost a lot of weight . This was an unexpected result. Is this dangerous?

  276. Is this fasting from just food, or are beverages included (ie, coffee with sucralose and cream, sparkling water, water,…)