Alternate Day Fasting, Weight Loss, and Food

A reader sent a link this morning to an interesting study of alternate day fasting for obese adults.

Even though the study participants ate whatever they wanted on their non-fasting days, they lost an average of 5.6 kilograms (about 12 pounds) after eight weeks, Dr. Krista A. Varady of the University of Illinois at Chicago and her colleagues found. […]

"People lost anywhere from about 7 pounds to about 30 pounds and that was in a very short amount of time," Varady said. And, she added, the program was pretty easy for the study participants to follow.

So, what did they do? Apparently oblivious to the underlying paleo principle at work, they’ve made the shocking discovery that if you simulate unavailability of food that people begin to revert to a normal [hunting] weight. News flash: wild animals including wild humans don’t have pantries and refrigertors or local supermarkets & restaurants. They’ve got to hunt, gather and prepare their food, and they’ve also got to think and plan in case migration or other measures will be required for future food. That all adds up, and it’s why HGs are typically lean.

To test alternate-day fasting in obese adults, Varady and her colleagues had 12 obese women and 4 obese men begin by eating normally for a two-week control period. Then, for eight weeks, they ate just 25 percent of the calories they needed to maintain their weight, between noon and 2 p.m., every other day.

So, they ate with no restrictions every over day, and on the "fasting" days they ate 25% baseline caloric intake in a 2-hr feeding window. So, not even a true fast in the way we typically do but still quite impressive in terms of results.

I’m fasting today until dinner and got in a pretty intense workout a couple of hours ago. This was my last meal, roasted chicken and a simple sauce. I had no chicken stock, but I do keep some of the Trader Joe’s paste packets around for just such contingencies. No unpronounceable ingredients. So, two chicken and one vegetable in 1 1/2 cups of water, to a boil; add about 1/2 tsp of tarragon, 1/2 tsp of bay leaves, and a light shake of paprika.  Then, about 1/3 cube of sweet organic butter. Reduce, then just a 4-finger dash of potato flour to thicken, which is no more than about 5g of carb.

Roasted Chicken Sauce
Roasted Chicken & Sauce

No veggies. Instead, I had a few walnuts and then 5 frozen cherries in some full fat yogurt.

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  1. Marnee on November 13, 2009 at 14:24

    What they have done is increase lipolysis, by keeping insulin low, periodically, which is different than low carb paleo in that it keeps insulin under control all the time. Insulin interrupts the release of lipolytic hormones. This is similar to eating low carb paleolithic diet, of course, even without fasting. I have not seen any evidence that fasting on a low carb paleo diet will increase lipolysis significantly, although fasting does seem to come naturally in that paleo eaters will only eat 1-2 times a day.

    I did read somewhere that fasting (eating 1-2 times a day or less) does stimulate human growth hormone, which is probably a good thing.

    • Richard Nikoley on November 13, 2009 at 14:39

      Yep. Paleo combined with IF was the mainstay of my weight loss. Now that I’m just about done (I’d actually be fine & satisfied right here at 175) my fasting is much more intermittent & random, and, if I begin one and lose interest or something comes up like an opportunity to party, then it’s no big.

  2. […] Original post by Richard Nikoley […]

  3. KAC on November 13, 2009 at 15:21

    I saw that you bought a copy of “Them + Us.” I’d be really interested to hear what you think of it, and furthermore, a question. His website cites humanity’s preoccupation with modesty and cleanliness- I’m interested to see what his reasons are. Also, the reasons behind man’s love of art, music, dance, etc. I could take a guess but if you have the book, then I’d prefer to get the author’s reasoning. BTW this is the kac who posted the link on Art’s site.

    • Richard Nikoley on November 13, 2009 at 15:44


      Well, thanks for bringing it to everyone’s attention. I was immediately intrigued, for I do think that the major discoveries often come from imaginative thinking and accidents (looking for one thing but finding something far bigger) with the sole condition that the hypothesis doesn’t violate anything _truly_ known (unlike the diet-heart hypothesis, for example.

      Don’t know how long before I dig in in earnest, but I’ll get to it and eventually post my thoughts.

  4. Grok on November 13, 2009 at 16:02

    Imagine that… feed fat people less food and they lose weight! What will science reveal to us next?

    At least this stuff is getting out there a little now :)

    • Richard Nikoley on November 13, 2009 at 16:11

      In fairness, I think the takeaway point is that the dieters were far more successful than in many other studies I’ve read.

      And even more, I doubt they were eating close to anything paleo or even low-carb, probably even pigging on fast food on their free feed days, and they were still successful.

      I haven’t blogged much about fasting, lately — probably because mine are so random, now, that it’s no longer an “event.” Perhaps I should combining this with a paleo lifestyle will:

      1. Ensure even more rapid fat loss.

      2. Give one a template for eating for life.

  5. Sue on November 13, 2009 at 17:07

    Its the way you feed them less food which keeps them compliant. Low calorie daily is hard for a lot of people but low-calorie every second day is easier to comply with.

  6. Nicole on November 14, 2009 at 05:09

    From poking around on the various forums that talk about the Johnson Up Down Day Diet (and this is exactly it’s weight loss plan, eat as you please, 25% of your maintenance calories the next day), I found that Sue is right.

    People can diet for one day at a time. They cannot keep calories low for too long, but most feel that *anyone* can get through one day. People do have issues when they have a special event and they either miscalculate or forget and it lands on a “down day”, but most people seem pretty happy with the method.

    • Nicole on November 14, 2009 at 05:17

      Actually, I’m not certain JUDDD includes the explicit fast. I think his plan allows you to eat your 25% whenever you want. I don’t have the book, so I don’t know if the forum people had modified the diet to not include IF.

      Based on my experiences with VLCDs, I think it’s easier to *not* spread the calories out, but to eat them all a once or at least in a tight window that’s a late lunch/early dinner format. I’m actually really excited to see a successful study about this – I hope it gets more press.

    • Skyler Tanner on November 14, 2009 at 07:36


      Eat Stop Eat almost accomplishes this by default: start fasting at dinner, fast 24 hours, eat dinner again the next day which can be ~25% of your required kcals. The “magic” keeps showing up again and again.


  7. Big Will on November 14, 2009 at 09:11

    I see that everyone seems to advocate the meal during your fast days being dinner; I’m curious about the reasoning behind that. As an avid weight lifter, I’ve always worked under the assumption that the longer you go without a meal, the greater your chances of entering a state of muscle catabolism, leading to less significant decreases in BF%. I’ve been experimenting quite a bit lately with just skipping meals on my off days and have had great success, but I feel like if I were to fast for a full 24 hours, muscle catabolism would increase significantly. It makes sense to me due to the metabolic demands of muscle being fairly high as opposed to fat stores, making them a burden to any system in a fasted state.

    Of course, this situation applies mostly to people carrying around more muscle mass than average, but I still think it’s something to consider. The muscle you’re carrying around has a profound effect on your metabolism, and I don’t think it’s something that should be taken lightly.

    • Richard Nikoley on November 14, 2009 at 09:16


      Let me ask you a question. If you were to set aside everything you believe you know about this issue and just observe nature, the animals and particularly omnivorous ones, does it make any sense that not eating in 24 hours would degrade your musculature?

    • ThePaleoGarden on November 14, 2009 at 09:47

      Richard (and Will),
      To add to your comments about why fasting is not a bad thing, and why someone who is a bodybuilder who has never been exposed to why chronic anabolism will in the end lead to insulin resistance which causes in the end chronic catabolism…. I offer to the discussion from a blog post that buffeted something that Brent over at “healthcare epistemocrat“ wrote. it resulted in a decent exchange about clarifying for a non-paleo bodybuilder the difference between chronic and acute catabolism and the dangers of chronic anabolism so harmfully sought by many bodybuilders (and many inactive people on the standard American diet, as well).

      Will, basically:
      -constant anabolic state will lead to a constant catabolic state (brought on by insulin resistance)
      -Why? because your insulin will always be high because you’re eating all of the time
      -When you lose your insulin sensitivity you will at the cellular level be in a catabolic state. Diab0etics’ have their muscle mass waste away. Many bodybuilders who believe in chronic anabolism become diabetic.
      -Will, you are confusing the brief catabolic state (from a brief fast) with a prolonged catabolic state (e.g., starving)

      Again, the ironic thing, in a bodybuilder’s quest for constant anabolism, in the end a hormonal reckoning will cause catabolism brought on by insulin resistance, diabetes, and perhaps even metabolic syndrome.

      • Richard Nikoley on November 14, 2009 at 10:06

        Thanks for that. Really good post of yours. Just my personal experience, but most of my workouts (2 per week, 30 minutes, highly intense) are in a fasted state anywhere from 12-30 hours, and I never eat until at least 2 hours after, but often six.

        Been doing that for nearly two years and in that time have made gains of 200-300% in most routines and in some cases four times and more the amount of weight. I can vary intensity to bring on hunger or back off and kill it, at will.

        IF combined with paleo combined with intense workouts fasted gives you high resolution into hunger. Ultimately, it becomes your friend, not your dreaded enemy.

      • Big Will on November 14, 2009 at 13:16

        Thanks for the article, it’s definitely an interesting read! My only caveat is that the article seems to operate under the assumption that insulin receptors are being overstimulated, eventually causing insulin resistance. Wouldn’t eating the standard paleo diet alleviate this? I’m watching the Iowa/Ohio State game right now, so I may have missed something in the article, but from everything I’ve learned previously, I wouldn’t think insulin overstimulation would be a problem when on a low carb diet, regardless of eating frequency. I do, however, see the logic behind downregulation of the receptors due to constant stimulation, though.

        As for the issue of eating before a workout, I’ve established pretty well what works for me there. I just can’t throw around the same weights without food in my stomach, especially on days where I’m doing squats or deadlift. I think that this is something that everyone has to experiment with, though, because as you’ve pointed out, I know a lot of people who operate better during a workout without any food beforehand.

      • ThePaleoGarden on November 15, 2009 at 13:42

        Richard, indeed. Your writings on emphasizing the success you have had with workouts and fasting really have really sunk home with me. I skip on the chance to do a workout now if I don’t have at least 4-5 hours of fasting (preferably a minimum of 8-10).

        Will, my point about insulin resistance from constant eating was primarily toward those on a non-paleo diet. I think constant eating on a paleo diet will cause less damage because there will be lower average insulin levels, but giving your pancreas and receptors a break is a favorable thing to do regardless of how you’re eating. Also, regarding Richard’s points of IF and strength gains if you’re constantly eating before and after workouts, you’ll receive less benefit, less adaptation, less gene expression. Many good points are made in this regard by Dr. McGuff, DeVany, and Richard has really good posts on this subject, too.

  8. Low-Carber on November 14, 2009 at 12:21

    hello, i have a question about the amount of chicken you eat for lunch. How many ounces of chicken you have in a meal? Because today my lunch was just barbequed chicken, and i had about 14 to 15 ounces of cooked chicken. I weigh the meat i eat, and i think that i eat like around 13 to 16 ounces of chicken a day for lunch.

    Before, when i used to eat green vegetables i used to eat 9 ounces of chicken along with some vegetables. But lately i have been eating chicken alone for lunch without any carbohydrates. So i had to increase the amount of chicken i eat.

    Oh, another thing i wanted to comment is that Whey Protein Powder has some carbs. The Body Fortress Whey Protein Powder i use has about 5 grams of carbs per scoop, that’s why i quit eating vegetables so i could stay around 10 to 20 grams a day from whey protein i use.

    Oh by the way that chicken looked pretty good ;-)


    • Richard Nikoley on November 15, 2009 at 08:05

      I don’t often eat chicken. I never weigh anything, so I would never know how many ounces of anything I’m eating. Never weight, never count.

  9. Low-Carber on November 15, 2009 at 12:27

    Richard: I see what you mean. And indeed, weighing the food is like a dictatorship. I think that we must eat until we feel satisfied. But it does help a bit to weigh the food by portions. What i do is that i plan to eat about 12 ounces of meat, chicken or turkey every day. And if i feel hungrier i eat a couple of pieces of extra chicken or if i feel less hungry i eat less than that.


  10. Alex on November 15, 2009 at 13:43

    How does one resist cravings when fasting? If I don’t eat all morning, I’m hungry as anything by the time lunch comes round, and being a city dweller I’m surrounded by carb-laden (yet delicious) food temptation.

    Am I just being weak willed?

    • Richard Nikoley on November 15, 2009 at 14:13

      For me, it’s varied. Some fasts are easy as can be, others tough.

      It’s important to remember that we’re not necessarily adapted to fasting. Fasting is simply a means of modeling our natural state where we weren’t always successful in getting food. The idea is that the body uses that state to repair and use up broken down protein waste, which I deem beneficial as an acute stressor.

      I find that fasts are easiest if I eat my last meal as a late lunch, say 2pm-ish. That way, I only have a few hours of potential gnawing hunger before, and it’s pretty easy to get to bedtime. Then, I find sleep really kills the fast and by the time I get hungry again it’s only a few hours of holding out.

      But, that’s just me.

  11. Intermittent Fasting « At Darwin’s Table on February 1, 2010 at 13:34

    […] Metzgar – The Alternate Day Diet,  Conditioning Research – Intermittent Fasting, Free the Animal – Alternate Day Fasting, and of course Fitness Spotlight – The benefits of intermittent fasting. All are quality […]

  12. ehsan on September 6, 2010 at 22:20

    i started gym 5 month befor that time my wight was 53 and height is 1.81 .and after 5 months i increas just 5 km.
    i started muslejuse protien 2 weaks befor.
    im doing also heavy km.what is the reason that i didnt gate resalt means my weight in not increas much?
    i have to go to gym every days or alternate days?
    pleas give me some good workout.

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