Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
19 Mar

How To: Intermittent Fasting

After the great discussion last week following the 1 Meal vs. 3 Meals news post, we thought it was a great opportunity to follow up and delve into the nitty gritty of IF. Practically speaking, what does IF look like? Today we’d like to focus on the “window of eating,” a dimension of IF that got people talking last week.

Any brand of fasting can already seem a little daunting for the newcomer. (But for those whose impressions of fasting involve hunger strikes or gaunt figures sitting in meditation, we think you’ll be pleasantly surprised.) Reading about some options, and knowing your efforts will indeed be rewarded with true health benefits, makes the leap a little more inviting.

Let’s first put this on the table: there is no one way to do IF. The only real guideline is that, as always, the food you eat should be healthy. (It’s pretty clear how we choose to characterize that.) In addition to the substantial health benefits, the simplicity and flexibility are what draw people to IF.

As Mark said, he enjoys mixing it up beyond the use of one approach by missing meals naturally or on an unplanned basis in addition to full day fasts. Let your choice(s) fit with your personal/family schedule, natural rhythms, and your personality (some of us are meticulous planners and some are more spontaneous – “and that’s O.K.”). The point of IF is this: episodic deprivation takes your body “off the track” for a while and allows systems to reinvigorate and recalibrate (also known as up-regulating and/or down-regulating gene expression). Check out Mark’s previous post on IF for more info on the research and nifty benefits of fasting.

Here are a few ways to IF (in unofficial terms):

Skipped Meal:
As Mark alludes to in his comment in the 1/3 meals post, he likes to miss meals naturally or on an unplanned basis. When we listen to our bodies rather than blindly follow routine we find we’re not always hungry when mealtime comes around. Let yourself skip a meal when this happens, or plan a meal skip during a convenient time.

Condensed Eating Window:
As shown in the comments from last week’s post, this is a popular option. The day’s food intake is condensed within a set number of hours, often somewhere between four and seven hours. The timing of this window varies depending on the individual’s schedule and preferences. The time since you prior meal or until you next day’s meal becomes the fasting period.

Early and Late:
For some, this option is more easily managed than the condensed eating window. The day’s food intake and nutrients are balanced between an early meal and later afternoon/early evening meal.

Single Twenty-Four Fast:
Most people choose to have a normal dinner and then fast until the following evening. Others choose to extend the fast until the following morning. For many people, this can be a weekly routine. Others may integrate it on a monthly basis or as an occasional event based on their sense of progress/plateau.

Alternating Day Fast for Week (or more):
This approach is often credited with a deeper “cleansing” character. Some people do it once or twice a year. Others make a seasonal commitment. You can choose to drink only water or include teas/small amounts of juices during fasting days. On the alternate days, some people choose to eat normally, and some opt for reduced caloric intakes.

One tip: During your “window of eating,” however long or brief it is, don’t feel that you should eat more than you might be hungry for. It’s a unique opportunity to listen to your body’s signals. It also serves as a way to “prove” to your conscious brain that you can survive quite nicely on smaller amounts of food and that you don’t need to “make up” for those temporarily lost calories. Of course, eating according to the Primal Blueprint at all times whether fasting or not means that you are constantly refining your fat-burning skills. This, in turn, means that you are not so dependent upon regular meals to sustain normal blood sugar levels, physical energy and mental acuity.

Interested in trying IF for the first time? We’ll highlight the “condensed eating window” approach (one option among many) to get you started. This approach, particularly with a fairly extended window, is very doable and can seem less daunting as you get started. Choose your own timing and length of window based on your schedule and preferences. If you can’t decide, you can consider condensing your eating between the hours of eleven and 5:00 p.m. Look for a corresponding IF menu in this week’s installment of “Eat This Today, Feel Good Tomorrow” later on today.

Be sure to send your feedback. We’d love to hear your results!

*Florian Flickr Photo (CC)

Further Reading:

Post Workout Fasting

Modern Forager: My IF Success Story

Conditioning Research: IF Reduces Inflammation

Sponsor note:
This post was brought to you by the Damage Control Master Formula, independently proven as the most comprehensive high-potency antioxidant multivitamin available anywhere. With the highest antioxidant per dollar value and a complete anti-aging, stress, and cognition profile, the Master Formula is truly the only multivitamin supplement you will ever need. Toss out the drawers full of dozens of different supplements with questionable potency and efficacy and experience the proven Damage Control difference!

Subscribe to Mark’s Daily Apple feeds

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. are you seriously suggesting people fast? as in not eat? that’s called something isn’t it- oh yeah anorexia! i realize this is one day but you have written a suggestion for people to skip meals, or full days of eating once a week. So which is it MDA- skip meals or eat 5-6 small meals a day? i do understand the point you are trying to make of listening to our bodies, but i think there are much healthier ways of going about knowing when we are hungry and when we are not. and if it was as simple as stopping eating when we are full, we wouldn’t have people on diets and meal plans now would we? and intermittent fasting simply causes us to eat more faster.

    Rachel wrote on March 19th, 2008
    • you should research before you post, you are completely ignorant on this subject.

      Ron wrote on November 2nd, 2009
      • Did this person seriously type anorexia?

        Angel wrote on June 2nd, 2011
        • Lmaooo @ anorexia…. Reallly?

          Angel Lovelii wrote on October 7th, 2011
        • Um, this lifestyle is NOT anorexia. This person is clueless!

          Jessica wrote on November 15th, 2011
    • Yes you are hanging on to conventional wisdom a bit there. Who says that we need to eat all of the time, every day? What scientific research do you have that suggests that fasting is unhealthy for you? It’s just what you have been told since birth and thought never to question it. Just like in school when it is drummed into our heads that grains should be at the very heart of our diet. Try and keep an open mind when it comes to breaking conventional wisdom. IF is a great practice for health, not just for fat loss, but to give your body a break from constantly loading it up all of the time.

      Also please note that anorexia is a mental condition. It would be foolish to confuse fasting with anorexia as anorexia is the psychological condition which may motivate someone to fast to try and ruthlessly reduce their weight, not the act of fasting itself. Don’t knock it ’till you’ve tried it.

      David wrote on November 11th, 2009
      • This is clearly a more intelligent reply. NIce!

        Amy wrote on March 10th, 2012
      • Just a small nitpick to an otherwise good response…anorexia nervosa is a mental condition (and probably what the original comment was referring to) but in and of itself anorexia is a physical symptom, which presents as a decreased sensation of appetite. This can occur as a result of anorexia nervosa or a host of other medical conditions and drug reactions. It is not neccessarily indicative of something harmful…one would need to see what other symptoms were present.

        Agi wrote on March 16th, 2012
    • Clearly you haven’t done any research on intermittent fasting! The point of it is not solely to be able to listen to your body and know when you are hungry. Maybe you should do more reasearch or try it yourself before you start arguing against it. There are many doctors who agree intermittent fasting works. Read up a little more before you make such a ridiculous post my friend.

      steph wrote on June 4th, 2010
    • Anorexia is not the same as fasting! Anorexia is a mental condition not physical. It is when a person has mentally brainwashed him or her self into thinking they are fat. They will usually pick at there food and or eat sugary junk and starve themselves in other ways. Fasting changes the body’s physiology and allows the body to dump junk that has been accumulated over time. They are too completely different subjects. If someone refused to eat because they think that the food will make them fat would be considered anorexia. It is the mindset.

      Bulimia refers to mindset as well! Not throwing up. I means the person has an impulsive tendency and is more likely to throw up. They tend to eat 400 and try to run on the treadmill until they burn 400 calories.

      These conditions has nothing to do with fasting.

      kev wrote on July 4th, 2010
    • Yea i agree you don’t know what your talking about.So people who fast for religious reasons are anorexics?Besides that it would be more along the lines of bingeing which it still isn’t so…maybe its quiet time for you now.

      Brian wrote on October 19th, 2010
    • You should research more.

      Not anorexia at all.

      E.A. wrote on March 8th, 2011
      • Great link. Thanks for sharing!

        Madison wrote on February 22nd, 2012
    • read the post numb-nuts.

      Luther wrote on March 30th, 2011
    • Well said…Why the h*ll would you suggest this? Makes no sense to me. Furthermore I am very familiar with up/down regulating as you say and there is no scientific proof that fasting will cause this.

      paulo wrote on June 10th, 2011
      • actually, if you look at studies for caloric restriction and its ability to extend lifetimes etc, it makes sense. cr creates beneficial adjustments by putting the *organism* in slightly stressful situations, causing adjustments to be made through up/down regulation. with that said, provided that the person isn’t going to pass out or die of starvation, its quite plausible that hunger would be able to alert the body to make particular adjustments by up/down regulating genes that could be beneficial in terms of weight loss.

        ally wrote on June 16th, 2011
    • Rachel I’ve been caught a few times myself. I’ve posted some bloopers and guess what, they’re on record for all eternity. Now I tend to research before I post. If you wiki “Intermittent Fasting” you’ll get the information you need to clear up the confusion.

      Shadeburst wrote on June 28th, 2011
    • most people dont know nothing about fasting, as you just shown here, you have so much to learn, poor you. I kind of hate people like you very ignorant and stupid

      francois wrote on August 6th, 2011
      • Hate?! That’s a bit harsh.

        Liz wrote on May 2nd, 2012
      • But at least she don’t use no double negatives, like you done here.

        Sorry, sometimes I can’t help myself.

        Joe wrote on April 16th, 2014
    • A few points:

      1. I just started the Primal Blueprint with my husband a few weeks ago. I was seriously skeptical about the “eat when you’re hungry until you feel satisfied” since I was convinced that part of the reason I gained weight was a lack of willpower. The problem I had was that no matter how much I ate, I never really felt satisfied. Full does not always = satisfied. When I was “full” I could always manage to eat a little more until I was totally stuffed. Even if I stuffed my face until I felt sick, I noticed that about 3-4 hour later I was STARVING. Since I have changed my diet, I have noticed a huge difference. I finally felt something I never had never experienced before; a sensation half-way through a meal–that even though I wasn’t stuffed–I just could not force myself to take another bite. It’s like my body recognizes that it has all the fuel necessary. and the temptation to keep eating is totally gone. My point is that I’ve learned that when you eat highly nutritious food that your body craves, it’s EASY to follow the “eat when you’re hungry until you’re satisfied” guideline… because when you are actually satisfied, you feel hungry less often, or you eat half as much.

      2. From my experience, Intermittent fasting seems to be something I’m doing naturally with my diet. Some days, I just forget to eat a meal because I don’t feel hungry. This happens about every other day. I don’t feel like I’m denying myself at all, because it’s not a conscious choice. It’s just something that happens because without the sensation of feeling hungry, I don’t even think about food anymore.

      Anorexia (an eating disorder, marked by an extreme fear of becoming overweight, that leads to excessive dieting to the point of serious ill-health and sometimes death) and intermittent fasting are not the same thing… not even the same ballpark.

      Sophia wrote on August 14th, 2011
      • Absolutely!! It’s crazy how I went form being able to eat and eat and eat…and not be able to say no to not even being able to finish a kids meal at the restaurant I work at and not even care!! Sooooo awesome!

        Tabitha Davis wrote on November 7th, 2011
    • Idiot.

      Ignorant Troll. Do your research first.

      Me wrote on December 13th, 2011
      • Mind your manners! you don’t need to be offensive!

        Alvaro wrote on February 4th, 2012
    • “Anorexia”? “eat more faster”?
      What are you talking about?

      Alvaro wrote on February 4th, 2012
    • Actually, you’re last sentence isn’t accurate. I’ve been doing IF for the last month (lost 20lbs)using a 2 day fast, 1 day eat, 2 day fast, and 2 days eat plan and my appetite is significantly less than it was prior to IF. I also tend to crave healthier foods. Salads and meats as opposed to pizza (my former favorite meal). I’m not here to say it’s for everyone, but give it a shot before condemning it.

      Ryan wrote on February 8th, 2012
      • So you go 2 days without eating anything or how do you do it?

        Raghda wrote on May 8th, 2012
    • The ignorance in these comments is almost laughable. Do you even know what anorexia is?
      Just another person using the Internet to be “heard” even when wrong.

      Dan wrote on March 12th, 2012
    • anorexia is a disease, in which you cannot/don’t want to eat due to mental health issues. people fast for many reasons, spiritual and for health reasons, and for different lengths of time. did you even read the article? there are many different ways to eat, it is individual. there is not one set way. some people who are “fasting” don’t feel extraordinarily hungry. people can make their own decisions on what they feel is necessary for them, and fasting may be it…or eating three meals a day, or 5-6. maybe read more than one “health” article and form your own opinion.

      Melissa wrote on March 28th, 2012
    • Just have to say… If this is anorexia, why haven’t I lost ANY muscle since I began eating this way?

      That’s the biggest classic symptom of what anorexia does to you since you are afraid to eat pretty much ANYTHING.

      Agreed with everyone saying that people should research before they post.

      Some people will NEVER accept the Paleo lifestyle. My aunt is a nurse, and one day, she asked me how I kept so healthy and looked so good. When I told her about my lifestyle (hey, SHE ASKED!), she railed on the unhealthiness of all those saturated fats I’m getting, the evils of eating only once a day, lack of carbs, fasted exercising… That was when I was like, “screw it, I’m keeping the Paleo/Primal miracle to myself from now on.”

      Drumroll wrote on April 24th, 2012
      • Drumroll – I have had exactly the same experience time and again – I am asked how I have lost weight/look so good/ look so fit/look so well etc – and I start sharing the Primal Blueprint ethos and get shot down time and again on the spot! Usually by overweight/unfit people who are looking for a miracle shilst being addicted to and wearing the comfort blanket of conventional dietry wisdom – now I just keep it to myself and continue to get compliments!

        Sheena wrote on April 25th, 2012
    • “Fast to be healthy,” had said the Prophet (s.a.w.).

      I’m a muslim. And I fast. I am not anorexic.

      EM wrote on May 28th, 2012
    • Intermittent Fasting is NOT an attempt at weight loss. People who try it seem to be quite easily able to maintain a very healthy weight.

      zark wrote on May 28th, 2012
    • I have dyslexic aneroxia, I don’t think I’m fat enough.

      Darren the Barbarian wrote on June 6th, 2012
      • <3!

        Jen wrote on February 3rd, 2013
    • Kevin P Carey wrote on July 25th, 2012
      • Well said.

        Vanna wrote on April 1st, 2013
    • To the uninitiated it may seem like a drastic and unintuitive step, but there is actually a hell of a lot of research that backs up intermittent fasting. It has been shown in mice (and humans) to improve blood profiles of triglycerides, hdl and ldl levels. Increase insulin sensitivity, decrease abdominal fat (a key indicator for cardiovascular disease), decrease stroke and decrease cancer incidence. It has also been shown to reduce the risk of alzheimer’s, parkinson’s and other brain diseases in susceptible mice. If you consider the typical ‘back-in-the-day’ Homo sapien you would understand how it matches our original lifestyle of long periods without food followed by feasts. It is possible the one single lifestyle change that is most likely to increase your lifespan and later-life quality.

      Ali wrote on August 10th, 2012
    • I have been fasting every year since I was 25….sometimes two or three times a year….short water fasts of 3 to 11 days….and the longest was 23 days.. I think you had better do some of your own research before posting ignorantly on a subject that dates back to the begining of time… By the way I am on a water fast now, if anyone would like to join me.

      fancy47 wrote on September 10th, 2012
    • You are seriously reading without comprehension. Before you post a comment. Make sure you understand the subject so you would not seem as ignorant as you are right now.

      Jeff wrote on September 23rd, 2012
    • Chill Out Sistah!
      I’m doing IF for 1 month direct, and ate like 1800 calories a day. And no, it’s not called anaeroxia.

      Cima wrote on March 13th, 2013
    • ….and the FDA used to say to eat 12415125 servings of bread a day. Are you still following that? Doctors used to recommend smoking as well, do you follow that? Get with the times, or the times will leave you behind.

      Thomas wrote on March 28th, 2013
    • Anorexia? Lol, seriously?

      Greenhudler wrote on December 10th, 2013
    • Wow, some people really need to stop being so narrow minded and open up to other concepts of living as opposed to the ones that have been drilled into them from an early age by the fitness industry, Government etc.

      I do a 24 hour fast once a week along with skipping breakfast here and there and I am the fittest, best functioning, healthiest and greatest I’ve felt in all my 23 years of living. I’ve also been primal/paleo for the last few years and trying to reach my goal of 7% BF. I’m currently at around 9-10%.

      Ash wrote on February 5th, 2015
  2. Um, anorexia is far more than just not eating…that’s just the way it is expressed. Abstaining from food for a certain period of time is a common practice that appears to have some health benefits. And the world is not going to end if you are hungry.

    Katie wrote on March 19th, 2008
  3. Rachel –

    As Katie said, anorexia is a serious medical condition. Intermittent fasting is simply a way to structure your eating patterns in order to potentially receive a variety of health benefits – weight loss not being the main focus. It may not be for everyone. Some people may not care to do it, and others may find it exceedingly difficult to skip a meal. We are simply offering it up to our readers as an eating option that they should, in our estimation, consider trying.

    Aaron wrote on March 19th, 2008
  4. I’ll skip meals a few times a week, mainly breakfast or lunch. I’m usually not hungry when I wake up, so I usually don’t eat until a few hours later, at which point it’s lunchtime. Sometimes I’ll eat an early breakfast, and then find that I’m just not hungry come lunchtime, so I don’t eat. I find this style of eating much more natural and comfortable. I hate being forced to eat when I’m not hungry. It usually just leaves me feeling sluggish and bloated. I’d much rather eat when my body tells me to, not when the clock on the wall says it’s time.

    Mike Drew wrote on March 19th, 2008
  5. As a recovering anorexic, I really see your point Rachel. However, Anorexia is officially defined as amenorrhea for at least 3 months, refusing to maintain a bodyweight of at least 85% of normal, intense fear of fat or weight gain and a disturbance in the way one views their body. Fasting is certainly a technique that many anorexics use but not all who fast are anorexic.

    I use IF (with the approval of my doctor, even) for religious and health reasons and have seen only positives from it. It has not caused me to go back to my ED’ed ways.

    My only problem now with IF is eating past fullness once I finish my fast – any suggestions on that, guys?

    charlotte wrote on March 19th, 2008
    • a high fatty meal with a little protein.

      i really enjoy this as my meal back… its almost like a reward to tell you the truth! its dense enough to sustain you and fill you up right good.

      merengue 4 eggs whites to stiff points,
      mix 1 avocado, egg yolks, and baking cocoa powder,
      fold in avo/cocoa mixture in merengue,
      enjoy with some fresh berries 😀

      seriously tho… if you eat half and store the rest for a snack later… (holds for about 8 hours) or just cut the recipe down in half eating it all isnt a huge meal

      kmac wrote on April 16th, 2010
      • re: eggs, cocoa powder, avocado snack

        that sounds delicious, but do you cook the eggs at some point? or toss in lemon juice or anything?

        thanks for the suggestion!

        josh wrote on November 9th, 2010
      • Kmac, I am totally stealing that. It sounds delicious. Thanks :)

        Eriu wrote on June 5th, 2014
    • Use your eyes!

      Seriously :) Take a look at how much you want to eat, then cut out about 1/4 to 1/3 of it and only cook the remaining 2/3 to 3/4 of the food. You’ll find that you’re not full, but you’re certainly not hungry either. I usually keep it very high protein, moderate fat, and very low carbs just to keep the fat burning going.

      Depending on how much you usually eat, I’ve found that a good 12oz steak with some veggies is perfect for me. It could be different for you, or it could be more.

      Omar wrote on June 5th, 2010
  6. I could see avoiding IF if you’re prone to eating disorders or recovering from anorexia, though it sounds like Charlotte has managed it successfully. Psychological health is as important as, and inseperable from, physical health. However, IF itself does not cause anorexia.

    There really do seem to be some health benefits to IF, particularly for insulin regulation.

    Food Is Love

    Huckleberry wrote on March 19th, 2008
  7. I guess I’ve naturally, unconsciously doing some sort of IF for years. I almost never wake up hungry, so I often skip breakfast. And I find, interestingly, that if I skip breakfast, I almost never want lunch until 1 or 2 pm. However, if I eat breakfast, I’m hungry by noon.

    Migraineur wrote on March 19th, 2008
    • I do the same. When I tell people I only eat when I am hungry, I get statements like, Well it;s linch time. Aren’t you hungry? They just don’t get it.

      Kay wrote on October 29th, 2012
  8. charlotte,

    Wonder if that’s a vestige of the anorexic days. The sense that the “sacrifice” you just made is worth an “indulgence”. Many people report that they don’t eat as much after a fast as long as they understand that it’s OK NOT to have to make up for the lost calories, that you can stop eating when you are simply not hungry for the next bite (as opposed to waiting for the sensation of fullness – at which time you may have eaten more than is comfortable). One idea might be to take whatever meal you had planned post-fast and divide it into two halves. Eat one half now and allow yourself the option of eating the other half in 90 minutes….but only if you are still hungry. That might train your brain to use the primal signals of “hunger” and “non’hunger” versus having to consciously override a more hedonistic desire to simply indulge until overfull. Does that make any sense?

    Mark Sisson wrote on March 19th, 2008
    • i get what your saying, i like to use the one bite every 2 whole minutes. just slowing down your eating limits over indulgence after a fast. like mark says its an opportunity to really tell how much it takes to feel full, nad being full. eating SLOWLY is a great way to do it!

      kmac wrote on April 16th, 2010
  9. Fasting is NOT starving oneself. You can’s natural and has been done for ooohhhh….couple millions of years. Again, starving oneself with little or no calories is not the goal of IF. The goal is taking in your calories in a shorter time window, or taking a day off eating so your body can do some much needed internal gut cleaning and other health benefits. Most people with serious diseases have found much relief when they allow their body to heal. Healing takes alot of the body’s resources and energies, digestion takes up alot too. You still need nutrients, vitamins, minerals, essential fatty acids and all the wonderful stuff that helps us rebuild our sick cells and detoxify the body.

    If you want some more info, you can also check out a post I did on IF 101

    I also did one on my own personal reasons on why I choose IF for a lifestyle

    and here’s one on the benefits for health, cleansing and detoxification on fasting

    When you see people with plenty of muscle, plenty of health, living long and fasting…hard to think it is such a bad thing. Just ask Jack LaLanne!

    Mike OD - IF Life wrote on March 19th, 2008
  10. The benefits of fasting and calorie restriction also has some nice little research such as:
    – increased longevity
    – reducing oxidative stress
    – reducing inflammation
    – reduce risk of heart disease
    – improving neuroendocrine responses
    – increasing GH secretion
    – protective effects on heart, lung, brain
    – decrease in insulin resistance
    and other overall disease prevention and life extension factors….here’s about 20 or so studies on it all.

    Mike OD - IF Life wrote on March 19th, 2008
  11. Mike OD wrote: “Most people with serious diseases have found much relief when they allow their body to heal. Healing takes alot of the body’s resources and energies, digestion takes up alot too.”

    Come to think of it, whenever I get sick, I have no appetite whatsoever and can go days without solid food. I guess the body does know what it’s doing.

    Dave in Ohio wrote on March 19th, 2008
  12. Personally, when I come out of a fast I eat like a horse. I make up for the calories I skipped, or at least close. But I’m also very active and I don’t think my body wants a long-term calorie deficit.

    On another note, Indians in the Pacific NW traditionally used fasting to treat a variety of illnesses. Fasting and herbs were the first line of defense, and if that didn’t work, it was time to call the medicine man for some good old-fashioned placebo.

    But fasting was also a part of their life even when they were well. The men often wouldn’t eat for a day or more when they were on a hunt.

    Sasquatch wrote on March 19th, 2008
  13. Thank you Charlotte, I appreciate someone seeing my point as well.

    Rachel wrote on March 20th, 2008
  14. Mark – thank you for the insight. I think you have a point and I’m going to try the portioning you suggested. I think the problem is that when I stop my fast I feel like I should be able to eat my normal-sized portions but fasting kinda shrinks my stomach and it’s hard to accept that just a few bites makes me “full”. But I like your idea of reminding myself that if I’m hungry an hour later, I can just eat again then. Thanks for the common sense:)

    Rachel – it’s kinda funny. This topic is being discussed all over the blogosphere (something in the water?). Over here everyone is pro- IF, but other sites like The Weighting Game (which I love, btw) are totally anti- IF. Check out the comments over there.

    charlotte wrote on March 20th, 2008
  15. IF can also be used in conjunction with weight lifting to affect dramatic physique changes!

    Check out Martin Berkhan’s LeanGains website for more information and stunning before and after photos.

    Barry wrote on April 2nd, 2008
  16. We were not ment to take in tuns of foos evrey day. Even ouer digestive trak needs a rest. Less food is better. Anericans have such a wierd veiw on food. I think people who do this long turm will notice more energey, more vibrent skin, and over all health.
    From a Godly point of view. Its quite nurishing as well.
    Luke 4:4 (KJV)
    And Jesus answered him, saying, It is written, That man shall not live by bread alone, but by every word of God.

    Linz wrote on July 28th, 2008
  17. I like this idea of IF. I practice it in a small way of skipping breakfast most days of the week. Come weekend time, I’ll eat about two meals a day which tend to be heavier than my weekday meals.

    Earth Beauty wrote on November 17th, 2008
  18. I had a question about IF versus the warrior diet. One advocates not eating at all during the fasting window (IF) and the latter says that if you eat “light” during the fasting period, you’ll reap the same benefits. Which is true?

    Patrick wrote on November 21st, 2008
    • From what I have learned, it’s all about what your body comes to expect. If your body knows food is just around the corner, it will plan for it. To convince your body to burn fat since food is NOT just around the corner you have to demonstrate that by not taking in calories during the fasting period. Going light will just convince the body to slow down metabolism to “make it through” to the next meal. Also very important to avoid insulin spikes anytime around fasting – before and after especially.

      John wrote on March 10th, 2011
  19. Can someone give me advice. I have been IFing one and off for a year. I try to fast at least 20-21 hours. I find it hard to make it to 24 hours, but I’m working on that. Is 20-21 long enough to be considered a fast? I have found the definition of IF so broad at times that I really don’t know if I am IFing (or IFing correctly). Any advice woudl be wonderful.

    Travieso wrote on December 21st, 2008
    • 20-21 hours is definitely an IF, as a matter of fact, the benefits of IFing hit their max production at around 18 hours, everything after that is gravy…so to speak.

      James wrote on March 18th, 2010
  20. Travieso, 21 hours certainly counts as a legitimate IF period.

    mark sisson wrote on January 5th, 2009
  21. i had a question for mark.. hi i wanted to know if i have been intermittently fasting becausebfor years i eat only one meal a day between 9am and 3pm and before 3 i will have a snack. I lost weight this way awhile back and ive kept it off ive had a clean bill of health for a long time and my cholesterol is low and everything has been pretty much normal for a awhile . So all i wanted to know if what ive been doing is the same regimen youve mentioned on your website?

    tracey wrote on February 23rd, 2009
  22. tracey – Yes, you’re eating patterns could fall in to the realm of intermittent fasting and is perfectly healthy. There is no reason for anyone to be eating 3 regular or 6 small meals everyday. If you’ve found a formula that works for you then stick with it. Just make sure you are eating right otherwise (enough calories/healthy fat, low carb, high-density vitamin/mineral/antioxidant foods etc.) and you’ll be fine.

    Mark Sisson wrote on February 24th, 2009
    • Mark – isn’t the point of IF to break the routine ?
      It would seem that consistently eating one meal a day is a routine and by definition is not IF (nothing intermittent about it).
      I am not disparaging the eating pattern – whatever works. But it can’t be really called intermittent.

      I have done IF way before learning about primal anything usually starting with dinner and ending with breakfast so over 24hrs. Amazingly in the morning i would eat very little and feel very full. That was the main benefit for me – shrinking stomach -> shrinking portions for about a week after.

      TJ wrote on January 12th, 2011
  23. hello mark i just wanted to say thanks for the reply but i also had one question . Why is it so hard for me to get back to IFing if i make a mistake and start eating after 3oclock? it almost feels like im starting over for the first itme and the cravings for whatever i was eating will come back at the same time everyday and its like im in a battle with my body to start eating clean again.I usually wind out gaining 15 pounds if i dont get back on track.Tonight im struggling again but so far im doing better.How do i stay disciplined no matter what outside stresses im dealing with that make me want to eat when i dont want to.

    tracey wrote on March 18th, 2009
  24. hello mark i had another question for you. I have been reading the book about the fast-5 lifestyle and my question is as follows if the 5 hour window is good no matter what window you choose, then why is the 5pm to 10pm window so widely perferred? my 5 hour window is between 9am to 1pm nowdays and i keep feeling that if i suddendly change my window to 5pm to 10pm that i will start to gain weight and i dont want that.

    tracey wrote on March 20th, 2009
  25. Tracey, there’s no real magic to the 5 hour window in my opinion. Just do what works. As for your other question, if you are IFing and you decide to eat, you embark on a whole new set of hormonal changes, which include added hunger. If you are only eating one meal a day every day, you may be reducing the value of IF. You might try two meals a day for 6 days and then one meal on the 7th for a while.

    Mark Sisson wrote on March 20th, 2009
  26. hello mark thanks again for your reply, i have been eating one meal a day for many years but its usually what some people eat for dinner like baked chicken and vegetables and maybe sweet potatoes and a glass of orange juice. Afterwards i will go walking or if i feel like i’ll go jogging at the park near my house and on the weekends i go hiking in griffeth park. Ive never felt weak or lacking in energy its just i have had a problem craving sugar sometimes and if i eat at night at least in the past i would gain weight. This diet is a way of life for me the only thing that caught my attention was the focus on nighttime eating even though i usually get hungry only in the early part of the day and that may be due to the fact that i conditioned my body to expect food in the early part of the day. So far so good. Also i think i do eat about 1000 calories in the meal i have between 9am and 11am thats the new approach ive adapted since the first post i printed and when i first started this in 1997 i thought i had thought of this on my own, it was just an experiment…my friends thought i was crazy. Anyway thanks for reading my post i really appreciate it a lot .

    tracey wrote on March 20th, 2009
  27. Your body does this naturally anyway when you get sick or injured. I can remember not eating for a couple DAYS when I got the flu. And far from getting worse, I got better. And came out the other side minus a couple pounds of bodyfat. I wonder about losing muscle though….

    Skull Shirt wrote on June 2nd, 2009
  28. Hi,
    I think every one is different. If I ate anything at all like my hubby, I’d weight 300 lbs! Every year, it changes too… with age (currently 38) I just find it harder to stay in the same size clothes. I have to restrict my calories. It no longer matters that I lift and run and cycle and work out (sometimes a couple times a day.) If I want to keep the belly fat off and keep from getting chub-rub on the long runs (ouch!) I simply have to restrict my calories. It doesn’t matter that I don’t eat grains (I don’t). It wasn’t always this way… But, a combination of genes, job and age mean that I must have fasting periods, or slowly, but surely…a little muffin top appears and I have to slip a notch on the old brassiere. I want to fit the same size of clothing for my whole life. I don’t think aging = getting soft and flabby. But – if I told people how little I actually eat, they’d think 1) I’m lying or 2) I’m losing it somewhere along the line! lol. I’m not. It’s my body type and my desk job. I never eat at work – that’s 4 days per week, no calories for 10-12 hours a day. When I do eat, I eat like a horse…but, similar to what a horse eats (with protein) – a massive salad with all the fixins. I would not recommend this to everyone – but, some people have propensities that set them up to be fat. I happen to be one of those people. I find that fat makes it hard to hike to the beautiful places and fit comfortably in my clothes, so…I’m thrilled with IF and happy not to see an old practice getting some credibility thanks to research and people on this site.
    Our genes are not our destiny and a desk job =/= heart attack or diabetes…

    janice wrote on June 3rd, 2009
    • Working out twice a day (even if only on occasion) is probably too much. Your body needs time to recover from a workout.

      By not letting it recover you increase the secretion of cortisol. While some cortisol is absolutely necessary for life, and even healthy, too much causes the body to hang onto fat. This may be thwarting your ability to drop body fat.

      I’ve read that people who workout solidly three or four times a week often see more muscle built, and fat lost, than people who do so every day. The rest time and lower cortisol levels probably explain this. More muscle is built while resting than when you are actually working out!

      Drumroll wrote on April 24th, 2012
  29. sorry – I’m happy TO see an old practice getting creds.

    janice wrote on June 3rd, 2009

Leave a Reply

If you'd like to add an avatar to all of your comments click here!

© 2016 Mark's Daily Apple

Subscribe to the Newsletter and Get a Free Copy
of Mark Sisson's Fitness eBook and more!