Polishing the Phyique, and Improving Health, with Intermittant Fasting

“Success seems to be largely a matter of hanging on after others have let go.”

~ Publisher William Feather

These aren’t exactly the best two pictures in the world to convey the point I’d like to make in this post, but we’ll just have to roll with what we’ve got.



The preceding picture was taken in the spring of ’08, after having roughly a year’s worth of Paleo lifestyle under my belt. Not too bad from a body composition point of view, especially considering this was an “all the time look”. In other words, there was no “diet down” or dehydration measures taken before the photo. And, more importantly, no post-photo “photoshopping” to “nicen” things up. I chose this particular view, though, so that you could look closely at my lower back and oblique area from the rear. What you’ll see is the “last to go” remnants of stubborn fat retention and a bit of water accumulation. For most guys, this is body composition “ground zero”, where the war of “first on and last off” is waged. For females, this would be analogous to the notorious hips and thighs region. This is generalizing, of course. Everyone has their own, special, battlegrounds to contend with.

The following shot was taken just last week, and captures the oblique and intercostals region from another angle.


After 10 Months of Approximately 5, 24-Hour Fasts per Month

Now, I don’t know what difference in body fat level is represented between the two pictures – it’s not really all that much, whatever it is — though I do feel much tighter in the lower back/oblique/intercostals area currently as opposed to back in the spring of ‘08. What I can tell you this: Intermittent fasting (IF) is the final piece of the puzzle when it comes to stripping off the last of that stubborn fat from those “first on, last off”, problem areas; the perfect adjunct to the Paleo lifestyle.

And I should point out as well, that the second shot is representative of the way I look all the time; I can’t reiterate this enough. I don’t make this point to boast, but in order to demonstrate the effectiveness of this lifestyle and of appropriate use of the IF tool. Any other “after” shot you’re likely to see in a physique-related advertisement, or, for instance, a physique celebrity photo shoot, will be taken subsequent to a painstakingly elaborate (and miserable) diet-down and dehydration regimen, concocted specifically to better showcase the “ripped to shreds” look. It’s all an illusion, though, that doesn’t last more than a day or two past the shoot or the physique contest itself – the photos, however, live on in perpetuity, thus projecting the illusion of this being the subject’s year-round condition. One can only imagine the damage done to the subject’s metabolism and overall health by repeating this nonsense time and again.

But hey, that’s the vanity side of things. Lookin’ good “nekkid” is all fine and well – and, truth be told, it is a pretty good indicator of overall health (the above mentioned scenario not withstanding) — But what about the real, unseen and ultimately important underlying health related issues? Is IF really Paleo?  Is yin to yang, as Paleo is to IF?

Well, this is how I see it: Our pre-agricultural revolution ancestors lived their existence with varying periods of feast and famine. And every bit of current research on the subject of calorie restriction and/or intermittent fasting that I’ve come across indicates that these methodologies (calorie restriction and IF) improve overall health – everything from blood pressure control to inflammation reduction (C-reactive protein as a marker) to positive management of existing conditions, including, I might add, cancer. And I’m talking remission of the “big C”, here.

Note: Please, if anyone has run across studies contrary to what I’ve stated above, please, please, please clue me in. I’m much more concerned with being fully informed (and passing that along) than in being “right”.

Of course, chronic fasting (more properly termed here, extended low calorie consumption) – albeit healthy in and of the fact that it’ll put more years in the ol’ life reserves – is just an out-and-out miserable existance. Could this be the chief reason behind so many diet failures? Hmmmm. Me thinks it so. The good news is, though, that the positive health-related results obtained via the miserable chronic underfeeding route can be matched with an intermittent fasting regimen. Uh, let’s use the term “methodology” here, instead.

And why “methodology” vice “regimen”? Because I suggest going about IF in a totally random and organic fashion, the easy way. Never, never chronically; quite simply, your mind and body will not accept chronic IF and you’ll wind-up losing that hard-earned lean body (muscle and organ) mass. There’s a much, much better way to go about this. Easy intermittent fasting is simply skipping meals randomly and eating to fill later. Not much more to it than that. I like to skip random meals now and then – other times I’ll not eat for 24-hours or longer. Got a very busy day planned? A long day’s worth of travel ahead? Eat a hardy breakfast, then fast the balance of the day. It is best to be active when you fast so as to (1) keep your mind occupied (at least in the IF newbie stage – not so much a concern for the “experienced), and (2) signal your genes to conserve protein (muscle mass). Being active also deepens the temporary negative energy balance of the intermittent fast. For instance, I like to fast on sprint days, as the empty stomach makes me feel fleeter afoot. Everything I’ve studied thus far leads me to believe that it’s the transitory alternations between positive and negative energy balance, that accounts for the underlying mechanism – the silver bullet,if you will — for the positive effects attributed to IF. And for some individuals, this is the final tool required to bring down that stubborn, fasting insulin level. A personal observation of mine is that it is much easier to fast during the summer months, as opposed to the winter. I’d guess that this is due to an increase in the metabolism required to keep warm. It must have also served to keep northern climate Paleolithic man constantly on the move in the winter, hunting animals that had acquired thick layers of fat to carry them through the same period.  Something else that I’ve experienced in a fasted state is a heightened awareness and mental accuity.  You won’t ever get to this point, though, until you’ve successfully scaled the wall of carbohydrate addiction.

Essentially, we are designed to be intermittent eaters, but continuous metabolizers. We operate in a slight energy surplus during the day, followed by a negative energy balance during the night. In a healthy, lean individual, energy pool stores are constantly turning over; individuals whose insulin level is chronically high, however, cannot adequately access fat stores and, therefore, for them, the fat continues to accumulate, unabated. Insulin resistance can therefore be considered a survival mechanism, in the fact that it develops as a result of the body’s cells’ requiring protection against the continual onslaught of excess nutrients; a protection triggered due to the cells being already stressed from excessive nutrient content. The excess nutrient intake also serves to shut down autophagy, the consumption of damaged tissues within the muscle cell which fuels repair and regeneration. Growth Hormone release is stunted, and muscle gene expression is down regulated. The ancestral environment did not support chronic, elevated nutrient ingestion, nor was there ever  “a window of feeding opportunity” subsequent to a bout of energy expenditure (exercise, for us modern-day Paleolithics) to shovel in carbohydrate replacement drinks and protein powders.

Ideally, we’d eat only when the energy substrates in the blood fall to the point of triggering a need for replenishment. The true hunger signal is an elegantly simple energy management system, and one that you would, in fact, expect from evolution. Contrary to the continual drumbeat of mainstream “experts”, there is no “set point” level for body fat, body mass or metabolism. What evolution has endowed us with is a simple feeding strategy that endeavors to keep us on a random energy intake-to-expenditure path that favors the survival (and thriving, if conditions are right) of the organism. Now, if we’d only get out of the way and let this fabulous mechanism take its course.

In Health,


35 responses to “Polishing the Phyique, and Improving Health, with Intermittant Fasting

  1. Good stuff – still looking good Keith.

    with respect to IF and cancer here is a recent study I came across the other day:


    It is established that calorie restriction (CR) increases the resistance of cells to various stressors such as oxidative damage, excitotoxins, mercury and acetaminophen. Alternate day feeding (ADF) may confer greater stress resistance than daily CR of 30% or 40%. A recent study in three strains of mouse showed that a fast of 48 or 60h prevented toxic effects due to administration of doses 2-4 times the maximum human dose of etoposide, a chemotherapy agent which acts through increased oxidative stress. In addition, mice inoculated with neuroblastoma survived longer when pretreated with fasting, then given high dose etoposide, as well as not exhibiting toxicity. This increased survival was construed as evidence of differential stress resistance between normal and cancer cells, the cancer cells being only partially protected by the pretreatment fast. In clinical practice, increased differential stress resistance could lead to the use of much higher doses of chemotherapy agents, and in the absence of toxicity, make it possible to repeat the treatment to kill residual cancer cells. Humans are unlikely to comply with a total fast of longer than 24 or 48h, which may be insufficient to activate the same gene expression process. Based on published data we estimate that an optimal time period for development of stress resistance is 2-3 weeks when alternate day feeding is employed. Our previously published experience suggests that 2-3 weeks of alternate day modified fast in which subjects eat ad libitum one day and <20% of one’s estimated caloric requirement the next will confer a similar stress resistance. Compliance with this diet is high and greater maintenance of body weight is feasible. We hypothesize that a pretreatment of 2-3 weeks with the alternate day modified fast will improve outcomes in cancer chemotherapy, decreasing morbidity and raising cure rates.

    • Francis,
      The “5 per month” ratio is just what I’ve wound-up averaging. And I should clarify, too, that those are full, 24-hour (and sometimes longer) fasts. I also have many “skipped meal” instances interspersed throughout each month. There’s no planning involved, I just let the fasts and the skipped meals come as they will, randomly. Today, for instance, I’m fasting. I didn’t plan for it, it just came about. Tomorrow, who knows? I’ll roll with what my hunger and circumstance prompt.

  2. That’s random for sure, Keith! And that’s why it’s working so well. I think if you tried to do the same thing all the time, or didn’t listen to your body, it wouldn’t have the same effect. You are definitely “puffy” in the first pictures, like a bodybuilder. Now you are more Tarzan lean.

    I mostly do the skipped meal fast, typically breakfast. I will go until about 1 or 2 usually, sometimes until 3 or 4 pm. This depends heavily on what I ate the day before though. Sometimes I am hungry early in the morning. I think if I’ve overdone carbs I tend to feel that way. All that crap out skipping breakfast and eating 6 meals a day was not helping me out. I used to really NOT be able to function without breakfast because my sugar levels were all over the place.

    I didn’t see my midsection until I started IF. It was really unintentional. I just wanted to see if I could do it, because that’s sort of what I was doing on the weekend. I don’t really do it on a schedule or anything… I just wait until I’m hungry to eat. Some days it’s around 10:30 or 11am, and other days it’s way later. My attention in the morning is out of sight! I am practically buzzed. Once I really got off the whole-grain gravy train my tummy flattened out. But with the addition of fasting, I really feel lean and mean like a wild animal.


    • TrailGrrl,
      Much of my eating, unfortunately, because of my corporate workday circumstance, is still somewhat scheduled. I’d really love to take a sabbatical (for many other reasons, too, but…) and during that time, eat only when cued by hunger. Right now the only time I can truly do that is on the weekends and other days off.

  3. Keith:

    Amazing results combined with top-notch and personally verified information.

    You follow my stuff — don’t know how long — but I’ve been stressing for nearly a year the importance of IF.

    What you’ve shown here is its critical importance on SO MANY LEVELS. Additional weight loss and leanness is merely one effect (one evolution doesn’t care about, either).

    Anyway, I was just about to do a “results” post, as I have a couple of other progress / conquest stories to share with readers.

    You just took up the third spot.

    Thanks so much for the continual values you produce and share.

  4. Hi Keith,
    things are going good i am eating very lowcarb now and have lost 6 pounds so far.My question is should i eat a high carb meal one meal a week or one day a week like on sunday to keep my matabilism going so it dont get used to the low carb diet.I am in ketosis and read you keep your matabolism guessing or reved up by carbing up once a week.

    thank you Bill

    • Bill,
      IMHO, no, there’s no need to ever eat a high carb meal to “rev” the metabolism. Your body will adjust and run just fine in a low carb environment. Continual low carb was what your body was designed to run on.

  5. Hey Keith,

    Great post and excellent summary of why we all should be IFers. Your body composition improvements speak for themselves, great work.

    My wife started on IF about 3 months ago. She does it by skipping lunch 3 days per week on the days she works out. It has had excellent effects. She dropped yet another dress size, now being a size 0.

    I do IF by skipping breakfast and lunch twice a week and skip breakfast one other time. I have also started skipping lunches as well, driven mostly by hunger. I am just not that hungry at lunch time some days and I just roll with it.

    I am hoping to get the cancer protection as I am a survivor of bladder cancer back in 1999. IF should provide me with another level of protection. I am not sure how it works, but I suspect that excess blood sugar feeds the tumors. Fasting and eating right may keep the sugar low and allow the normal immune response to get rid of the tumor.

    Once the crap carbs are gone, IF is the next, very important step. Thanks again,


    • Jeff,
      I seem to remember that cancer sells are different form normal cells in their inability to metabolize ketones or free fatty acids for energy and, in the absence of elevated blood glucose, will die. Maybe I read this a while back in the book Power, Sex and Suicide? Which, btw, is a fantastic read. I wish I could elaborate on what I’ve just stated — this is just off the top of my head. It might be something you’d want to investigate.

  6. Thanks for sharing Keith.
    I average 3-4 times a month for 24hrs.
    for anyone that’s intersted, IF is “DA BOMB” when it comes to business travel. I eat a large meal before I leave and I just don’t worry about eating again until the next day breakfast, where I’m always able to find eggs and bacon no matter where I’m staying.
    In sharp contrast to the neurotic obession of the past, “oh my g;d I’m missing a meal, I didn’t get my 6 meals today, where is a powerbar??!!!”

    Thanks for posting the pics also, proof sure is in the pudding!!


  7. Jeff, Keith,

    Remember what Good Calories, Bad Calories says, that cancer cells have a “Selective Growth Advantage” whereby they seem to have more insulin receptors than your standard non-cancerous cell. And in the insulin-induced world where we live, it is no wonder that they are super-fueled; literally throwing gas onto the fire.

    Nonetheless, I’ve been doing IF, but not consistently. I think I’ll make an effort to do that at least once per week.

    Pretty impressive pictures Keith. You give us all something to strive toward.

    • Andy,
      Good point. And thanks for the props. It requires so little effort, though. Really, if that’s one point I could truly express to everyone, it’s this: there is really no magic to this at all.

    • Fitnessbuff,

      The more fasts you undergo, the better your body (and mind, too, for that matter) will adapt to them. After a while, you won’t even pay much attention to your fasting, other than to realize you’ve got some extra time on your hands. If I had to guess, I’d say your body is still not truly efficient at burning ketones for fuel. This is why I consider IF to be the final step in perfecting the TTP/Paleo lifestyle.

  8. I completely agree with everything. First off I started IE this weekand for the first time in a long time my weight has reached a new low. This does seem to be the last piece of the puzzle.

    Also hunter gatherers would only eat one meal a day. So that constitutes a 24hr fast everyday. So its a good idea to fast for sure!

    • Dr. Dan,

      I don’t think that for fat loss purposes, you’ll derive much added benefit from doing more than a couple of fasts per week. This has just been my experience, and what I’ve seen in others. Of course there are always “outliers” that will respond differently, so by all means, feel free to experiment.

  9. So interesting, this. I just stumbled onto your website from a swedish low-carb site. I just started out myself with reducing the carbohydrates, I haven’t left the diary procucts behind me yet, but as I get more used to my new diet I use less and less of them. The IF is another thing though, I’ve been doing that naturally just about my whole life, always wondering if there was anything wrong with me 🙂
    I can skip breakfast any day, and on free days I almost always skip lunch too. More often than not I eat to be social, at work and at home with the family. Of course I’m hungry once in a while too, but not necessarily at meal time.
    How wonderful to get a name on what I’m doing – when my husband asks me why I don’t eat lunch when I’m away a day shopping (ha, talk about hunting and gathering 😉 ) I can say that I’m IF:ing, and it’s good for me! 😀

    • Pixelpig,
      It’s wonderful to be able to put a label on something rather nebulous, huh? As far as dairy goes, I’m still on the fence. I think that raw dairy, in moderate amounts, and for those who are lactose tolerant, may not only be “ok”, but actually beneficial. I’m waiting to hear back from Dr. Scott Connelly before I make a firm decision one way or the other. It may be that the insulin response to lactose (in those who are lactose tolerant) is negligible, therefore rendering raw dairy suitable for a Paleo diet.

  10. Keith,

    This IF idea sounds great, a few questions though. All the information I’ve read and gathered stresses the importance of the fact that the body cannot store protein. When one works out roughly three times a week with low repetition/high intensity mass exercises (pullups, dips, deadlift, squat, bench), these muscles are inevitable broken down. In order to repair them, it is stressed that you must have a steady supply of protein (about 25-30 grams every three hours) in order to maximize your muscle gain and muscle recovery for your body cannot store this protein for later use. Are you saying that when practicing the paleo diet and using IF the body instead uses the broken-down muscle fibers via the process of autophagy to make up for that lack of protein, in turn actually building muscle more efficiently because you are consuming the damaged tissues of the muscle? This sounds amazing, if it is true, and what do you suggest for those of us transitioning to the paleo diet now who may not yet be able to achieve a state of autophagy and don’t want to lose (and hopefully even continue gaining) muscle mass?

    • Justin,
      The body does store protein, in the form of skeletal muscle. Also note that there exists a continuous turn over of protein in the body (which you have alluded to here), as it naturally cycles between periods of anabolism and catabolism (build-up and break-down, or positive/negative nitrogen balance). I think you’re tending to look at this through the prism of a very narrow time frame (hours), when, in actuality, you should think of net-positive hypertrophy gains over the long haul (days, weeks). The hormonal stimulus of an intense workout will remain well beyond any fasting period, with a resultant, compensatory, positive nitrogen balance established later on down the road. The body has evolved quite well to respond to intense physical demands under temporary shortages of food. It will take care of any necessary overcompensation (hypertrophy) when adequate nutrient intake is re-established.

  11. Thank you for writing about IF. I incorporated it into my life after I had been practicing an Evolutionary Fitness way of eating and working out for a while. An 18-24 hour fast is the only way for me to lose that little extra layer of fat around my lower belly. I only do it twice a month or so, but it really does the trick!

    • Kat,
      The combination of a high fast-twitch muscle fiber percentage with intermittent fasting really does the trick for that last few pounds of stubborn fat.

  12. Great blog/site. I started a weekly 24 hour water only fast a month ago as a aging/longevity experiment (not to loose weight). I am 47, have about ten lbs. less muscle mass than you, but am otherwise in similar condition. At the end of my 24 hour fast I do 45-60 minutes of cardio exercise. My thought process is that by adding the cardio at the end of the fast I am combining the two most powerful Autophagy drivers (nutrient scarcity and low oxygen levels). I hypothesize that the two act together synergistically to sky rocket autophagy (no, I don’t have any evidence of that). A few questions please: 1. Are you doing water only fasts, or do you drink juice or some other calorie containing beverage during your fast? 2. You say “The excess nutrient intake also serves to shut down autophagy”. How do you know that? I am not saying you are wrong, I intuitively agree with you, but I don’t know of any general scientific consensus or evidence to that statement.
    3. Maybe it is just the exercise at the end, but I have to sleep for a couple of hours after first eating following the fast. Is that your experience? Do you have a limited number of things that you eat for your first meal after the 24 hour fast? (I recently had a bad experience eating spicy food after one of my fasts.)

    • Interesting hypothesis, JD. Oh, to be a research scientist with an endless grant, huh? 🙂 My fasts just “are”, that is to say, I may eat nothing for 16 to 30 hours, I may have a handful of nuts, some nut and/or coconut butter in between, whatever. I just go with the flow, with what is, and leave it at that. I rarely do juices of any sort (at any time), though I do partake in all forms of raw, unpasteurized dairy.
      On “excess nutrient intake dialing down autophagy”: I have nothing to back this claim, however, it does make sense to me that it would be so. I believe an organism would, in the presence of outside calories — and in an evolutionary/survival sense — prefer those calories over self-cannibalization. All organisms are geared toward procreation in times of plenty and “mere survival” during lean times; the human organism ought not be too far (if at all) removed from that notion.

      I haven’t run across anything yet that I avoid (that I wouldn’t normally avoid) when breaking a fast. I have experienced the after-meal drowsies, though.

      • It has now been about 9 weeks since starting my weekly 24 hour Amplified Fast (TM). The day following the amplified, water only fast, typically Tuesday, is the worst; fatigue, difficulty concentrating, joint pain, memory problems, nausea. The rest of the week is better, but still some fatigue, difficulty concentrating and memory problems. The day of the fast is now one of my highest functioning days of the week, and I am kind of looking forward to the next Fast day. Most people would probably view these adverse post fast effects as a set back, I view it as an indirect confirmation that I am inducing the intended hyper autophagic response during the final hour of my Fast. To what end, I am not certain, but I am not detered either. It is too soon to make any positive claims, but I can confidently say that I don’t look any worse.

        • Hmm, I don’t suffer any of those adverse, post-fast effects. A couple of questions: (1) how long have you been following a Paleo diet? Are you totally free of grains and simple carbs? (2) what is your activity level on fasting days?

  13. Keith,

    I’ve been doing some thinking on fat storage, IF, and insulin management. We’ve discussed before the notion that obviously a diet that controls insulin can only cause weight loss to a point. That point, however, is usually a healthy body fat level that would be evolutionarily sensible for most people.

    It seems that after that, you need IF or caloric restriction to continue shedding fat and actually get ripped.

    Here’s my question: There are many IF’ers, including Brad Pilon and Martin Berkhan (leangains) who swear that IF works because it’s just another way to reduce calories. And yet, it also causes decreased daily insulin load and increased insulin sensitivity. Isn’t there a confounding variable here?

    They claim caloric restriction is what’s working, but decreasing the insulin load throughout the day and heightening insulin sensitivity must play a factor. But how to tell the two apart. I wonder, if you started injecting insulin during your fasts, and added no calories throughout the week, if you wouldn’t release less fat throughout the day, be starving, and start eating muscle or literally starving in some other way? If that were the case, wouldn’t it disprove the theory that IF works because of caloric deficit?

    As you can see, I’ve been thinking a bunch about this, and I was curious as to your thoughts. I’ve become somewhat frustrated recently by reading the blogs of IF ‘gurus’ whom I would assume would be above the “a calorie is a calorie” belief system.


    • To be totally honest, I don’t know. And I’d go a step further and state that if anyone tells you definitively that they do know, I’d be highly skeptical. At the very least, I wouldn’t buy a used car from them. There is much going on, and too many variables to get a handle on, at low BF levels. What may be mis-identified as fat, may actually be water retention. It’s known that cortisol precipitates water retention, and stress increases cortisol — stress that may come from work, working out, fasting, anything you can imagine. This is just one example of the myriad of things going on in the body — too many things for a person to realistically get a handle on. Now, that said, if I were trying to shed the last few pounds of fat on my body I’d set up conditions that I could control — namely, I’d (1) hibernate, (2) IF frequently, as much as I could tolerate, (3) take in very little, if any, carb and (4) engage in in-frequent, super-high intensity, power-based workouts.

  14. I was introduced to the Paleo For Athletes book a few months ago and have since really been following the Primal BluePrint. A client introduced me to the latter and he IFs once a month with great result. He is a DO and I already eat intermittently and I will be following his lead. Thanks for a great post!

  15. Hi Keith,
    Kind of an old thread but I wanted to know what you thought of Martin Berkhans leangains protocol? I’ve heard it mentioned on Robb’s podcast several times.



    • I can’t give a true assessment of Martin’s program, Rolant, because, quite honestly, I don’t know too much about it. It does seem to work for Martin, though, and I assume many others as well. I will say that I think intermittent fasting works best when it occurs quite naturally and randomly as opposed to being part of any kind of a planned methodology. But that’s just my way of dealing with diet and fitness in general, and in that sense you could say I’m much more at home in the DeVany-esq tribe. This is also why I refrain from any kind of a “weigh-and-measure” approach to calorie intake. I think it’s much more important for long term health to learn to listen — and respond accordingly — to the true demands of your body.

      • Thanks for your feedback. I guess I’ve been naturally following this then, as I’ve skipped meals out of necessity(work/school) and ate later.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s