Intermittent Eating

by Jose Antonio, PhD.  Eat frequently and spread it throughout the day.  Perhaps 6 per day.  Get 20 grams of protein minimally per meal.  Don’t skip any meals.  Whoa Nellie.  Hit the rewind button.  Ooops.  Generation “Z” has never seen a rewind button.  Uh. Instead hit ‘ctrl alt delete.’

Is the general advice given at the top of the page passé, wrong, or misguided?  Absolutely not.  It works and works well.  Increasing meal frequency can preserve lean body mass (during times of caloric restriction oddly enough) and have a positive effect on markers of health as well as appetite control.[1]  And there’s new evidence just published in the Journal of Nutrition (authors: Memerow MM et al) that spreading your calories evenly versus skewing them towards dinner results in a better anabolic response.

When it comes to gaining lean body mass, the two most important dietary factors are total calories and protein.  I imagine most members of the ISSN can single-handedly eat more than a family of four in the Philippines.  But as they say in Texas, “there’s more than one way to skin a cat.”  But if you’re from Florida, I guess it would be “there’s more than one way to peel an orange.”

So what exactly do you mean Professor Antonio?  Well here’s my pop quiz of the day for you.

What do worms, mice, rats, and perhaps us humans have in common? 

If you guessed that caloric restriction seems to lead to a longer life, then go to the head of the class.[2-6] In fact, both fasting as well as intermittent fasting seem to trigger a cascade of physiological events similar to caloric restriction.[7]  Now most of you view eating as a means to an end.  That end being recovering from exercise, increasing body weight and if you play your cards right, an improvement in body composition. But can you achieve similar ends (i.e. better body composition) via a route other than for instance macronutrient manipulation?  Can NOT eating sometimes be a good thing?  Well, put on your reading glasses and take your ADD meds.  See if you can follow the data.

Perhaps the most widely known (and widespread) period of fasting is during the month of Ramadan (the ninth month of the Islamic calendar).  The daily period of fasting starts at sunrise and ends at sunset.  No food, drink, smoking, or sex.  Yikes.  Count me out.  That’s cruel and unusual punishment.  Thomas Jefferson would not be pleased.

So what happens (or doesn’t happen) during Ramadan?  I found some interesting scientific observations.

1)      Hypertrophic training in a fasted or fed state during Ramadan has no effect on body composition in bodybuilders.[8]

2)      Fasting during Ramadan did not worsen glycemic control in type 2 diabetics.[9]

3)      Ramadan fasting results in a loss of body weight, body fat and fat free mass.[10]

4)      Ramadan fasting may lead to a drop in anaerobic power.[11]

5)      Increase in fatigability during training.[12]

6)      Significant improvement in cardiovascular disease risk factors.[13]

The summary above is by no means a comprehensive one.  For that I’d suggest you go to PubMed and read the umpteen studies done on the effects of Ramadan.  Fascinating stuff for sure.  I think the biggest obstacle in dealing with fasting, and more specifically, intermittent fasting (or IF) is that there isn’t a clear definition of what makes something ‘intermittent.’

One study defined IF as severe caloric restriction one day per week.  For me, that’s awesome! So I can smoke and drink the other 6 days a week.  JK.  This recent study looked at overweight women to see what impact IF with caloric restriction (IFCR) had on various measures.  The kicker was that some women ate a liquid diet.  We’ll call that IF-liquid.  The other group consumed a food based diet or IF-food.  After 8 weeks, they discovered that both groups lost similar amounts of fat; however, the IF-liquid group tended to lose more (6.2 pounds) compared to the IF-food group (4.2 pounds).  Reductions in total and LDL cholesterol levels were greater in the IF-liquid group as well.  So here’s a study showing that liquid delivery of calories works better than solid food to help fat women become not so fat.[14]

Another clinical trial used a different approach to IF.  The FCR (or Fasting and Calorie Restriction) approach used by these investigators was as follows:  There was a reduction in caloric intake of 300-500 calories per day compared to baseline.  In addition, this was combined with two days of ‘Muslim Sunnah fasting per week.’  This lasted 3 months.  A total of 32 healthy 60-year old men were randomized to either the FCR group (and were instructed to follow a calorie restricted dietary regime with intermittent fasting) or to the control group (in which individuals were asked to maintain their current lifestyle).  They found some intriguing results indeed.

Significant decreases in tension, anger, confusion and total mood disturbance and improvements in vigor were observed in participants in the FCR group compared to the control group. Body weight, BMI and percent body fat were reduced by 3.8%, 3.7% and 5.7% respectively in the FCR group.  So my USA Today headline would state that “FCR makes you happier and you lose weight and fat to boot!”[15]  Of course, are these subjects happier because of the method of fasting?  Or are they happier because their bellies no longer flop over their belt buckle?

Bottom line:

  • If this is confusing to you then join the club.
  • Fasting and more specifically intermittent fasting or IF suffers from the same fate as beauty.  It’s hard to define beauty, but we know it when we see it.  So what exactly is IF?
  • Is it the sunrise to sunset fast seen during the month of Ramadan?
  • Is it severe caloric restriction one day a week?
  • Is it skipping dinner five days a week and eating most of your calories early in the day?
  • Is intermittent fasting really the same thing as intermittent feeding which is really the same thing as skipping meals on occasion?  Didn’t your momma tell you not to skip meals?

What’s your goal?

  • If your goal is losing body fat so that you look pretty in a selfie, giving IF a try may indeed be worth it.
  • If your goal is overall general health and you’d like to live longer than a Galapagos tortoise, then fast away.
  • If your goal is gaining lean body mass, then avoid IF the way a gazelle avoids a cheetah.  Run away…fast!
  • If your goal is performing optimally in a sport, you’d be a fool to try it.

So sports nutrition smarty-pants, what’s your goal?



1.           La Bounty PM, Campbell BI, Wilson J, Galvan E, Berardi J, Kleiner SM, Kreider RB, Stout JR, Ziegenfuss T, Spano M, et al: International Society of Sports Nutrition position stand: meal frequency. J Int Soc Sports Nutr 2011, 8:4.

2.           Uno M, Honjoh S, Matsuda M, Hoshikawa H, Kishimoto S, Yamamoto T, Ebisuya M, Yamamoto T, Matsumoto K, Nishida E: A fasting-responsive signaling pathway that extends life span in C. elegans. Cell Rep 2013, 3:79-91.

3.           De Petrocellis L, Di Marzo V: Cell signalling: why fasting worms age slowly. Nature 2011, 473:161-163.

4.           Martin B, Mattson MP, Maudsley S: Caloric restriction and intermittent fasting: two potential diets for successful brain aging. Ageing Res Rev 2006, 5:332-353.

5.           Mahoney LB, Denny CA, Seyfried TN: Caloric restriction in C57BL/6J mice mimics therapeutic fasting in humans. Lipids Health Dis 2006, 5:13.

6.           Kokaze A, Ishikawa M, Matsunaga N, Yoshida M, Makita R, Satoh M, Teruya K, Sekiguchi K, Masuda Y, Harada M, et al: Longevity-associated mitochondrial DNA 5178 C/A polymorphism is associated with fasting plasma glucose levels and glucose tolerance in Japanese men. Mitochondrion 2005, 5:418-425.

7.           Anton S, Leeuwenburgh C: Fasting or caloric restriction for healthy aging. Exp Gerontol 2013, 48:1003-1005.

8.           Trabelsi K, Stannard SR, Ghlissi Z, Maughan RJ, Kallel C, Jamoussi K, Zeghal KM, Hakim A: Effect of fed- versus fasted state resistance training during Ramadan on body composition and selected metabolic parameters in bodybuilders. J Int Soc Sports Nutr 2013, 10:23.

9.           Sahin SB, Ayaz T, Ozyurt N, Ilkkilic K, Kirvar A, Sezgin H: The Impact of Fasting during Ramadan on the Glycemic Control of Patients with Type 2 Diabetes Mellitus. Exp Clin Endocrinol Diabetes 2013, 121:531-534.

10.         Norouzy A, Salehi M, Philippou E, Arabi H, Shiva F, Mehrnoosh S, Mohajeri SM, Mohajeri SA, Motaghedi Larijani A, Nematy M: Effect of fasting in Ramadan on body composition and nutritional intake: a prospective study. J Hum Nutr Diet 2013, 26 Suppl 1:97-104.

11.         Bouhlel H, Shephard RJ, Gmada N, Aouichaoui C, Peres G, Tabka Z, Bouhlel E: Effect of Ramadan observance on maximal muscular performance of trained men. Clin J Sport Med 2013, 23:222-227.

12.         Aloui A, Chaouachi A, Chtourou H, Wong del P, Haddad M, Chamari K, Souissi N: Effects of Ramadan on the diurnal variations of repeated-sprint performances. Int J Sports Physiol Perform 2013, 8:254-262.

13.         Nematy M, Alinezhad-Namaghi M, Rashed MM, Mozhdehifard M, Sajjadi SS, Akhlaghi S, Sabery M, Mohajeri SA, Shalaey N, Moohebati M, Norouzy A: Effects of Ramadan fasting on cardiovascular risk factors: a prospective observational study. Nutr J 2012, 11:69.

14.         Klempel MC, Kroeger CM, Bhutani S, Trepanowski JF, Varady KA: Intermittent fasting combined with calorie restriction is effective for weight loss and cardio-protection in obese women. Nutr J 2012, 11:98.

15.         Hussin NM, Shahar S, Teng NI, Ngah WZ, Das SK: Efficacy of Fasting and Calorie Restriction (FCR) on Mood and Depression among Ageing Men. J Nutr Health Aging 2013, 17:674-680.


Come hang out with all the sports nutrition smarty-pants at the ISSN Conference and Expo, June 20-21 in beautiful Clearwater Beach FL,