So, if increasing meal frequency does not have an effect, wouldn't decreasing meal frequency, as in intermittent fasting, then be as futile? Or does decreasing meal frequency from 5-6 small meals a day to a single gorgeous feast even predispose to obesity, as you may have heard it on CNN only yesterday?
"Intuitively", yet not as in genetically programmed, but rather as a result of lifelong medial and educational indoctrination, it occurs to us only reasonable that someone, who crammed his/her whole daily calorie intake of 2.400kcal into a single meal, when his/her body is used to 3x or 4x 600-800kcal servings, would gain (fat)weight - especially if there are some of those nasty fattening carbs around the "new smarter(?) generation" of dietitians has finally identified as the root of all metabolic disease. Accordingly, you will probably not be surprised by a remark I took from a review of the effects of meal frequency on weight gain and body composition by Bellisle et al. from the year 1997 (Bellisle. 1997)...
[A] very large bolus meal with a high carbohydrate content might saturate the maximal rate of glycogen synthesis and force additional disposal via de novo lipogenesis; there is much evidence to support a hyperlipogenic effect of gorging in animal studies.Now, while intermittent fasting obviously allows for several smaller meals within a 4-8h time window, it seems logical that the "saturation" of glycogen synthesis could nevertheless become a problem. After all, you have read about the limited ability of our bodies to "store away" excess glycogen in previous posts on the SuppVersity and will thus be familiar with the idea that, contrary to the fat storage capacity of our adipose tissue, our bodies' glucose stores, which are located primarily in muscle and liver tissue, are very limited.
"How much fat can you really gain from a single 750g carbohydrate meal?"*
* this is the answer to the question at the end of yesterday's installment of the Intermittent Thoughts on Intermittent Fasting series
|Illustration 1: This is a very theoretical calcuation of what "could" happen if you ate 19 cups of cooked pasta = 750g of carbs after a glycogen depleting workout (calculations based on estimates by Acheson. 1988)|
In 1988, Acheson et al. established in a series of overfeeding studies that it takes roughly 475grams of excess carbohydrates to manufacture and store 150grams of fat (Acheson. 1988).
You may notice that this would yield an energetic ratio of 1g of fat to 3g of carbs and thus constitutes another violation of the generally accepted oversimplified "laws of dietary thermodynamics", as they are propagated by dietitians and mainstream-media. If our bodies could inter-convert and store macronutrients as readily as people are made to believe, according to the 4kcal/9kcal energy rule, the 750g of carbs in my sample calculation in illustration 1 should translate into 111g of fat, if 500g of the carbs had previously been stored in empty glycogen stores.
|Image 2: R. Feinman (photo) and Eugene Fines authored a paper on the fallacy of the "a calorie is a calorie"hypothesis|
Yet, before we are delving any deeper into a discussion of optimal macronutrient composition for lean gains, weight loss and optimal performance (we will get to that in a later part of this series, I promise), let's get back to the topic at hand and look at some of the research that may be able to explain, why anecdotal evidence clearly shows that, on a combined exercise + intermittent fasting regimen, as Martin Berkhan and others recommend it, weight gain never seems to become an issue - and that despite the fact that many of his followers claim they even had to force themselves to eat the prescribed amount of food.
Myth 2: A lower meal frequency equals (fat)weight gain
|Illustration 2: Comparison of feeding schedules on "normal diet", alternate-day-fasting (ADF) and the current interpretation of intermittent fasting (IF).|
Although the small breakfast most of the Muslims ingest before dawn and the additional abstinence of fluid intake distinguishes Ramadan from intermittent fasting, the average period dieters remain without food (from 4am to 7pm, i.e. 15h) is comparable and, what's equally important, the length of the fasting and thus the study period (one month) is long enough to bring about measurable effects.
|Image 3: After ~13h of fasting 78% of your liver glycogen stores of roughly 300mmol/kg liver tissue will be depleted; 3h left until your body will have to come up with "alternative" fuel sources.|
|Figure 1: Changes in energy intake during and body composition in the course of Ramadan fasting in 10 healthy physically active (min. 3x/week) men (data calculated based on Trabelsi. 2011)|
|Figure 2: Effects of 22 days of alternate day fasting (ADF) on body composition (lean mass and fat mass in kg) in 16 non-obese, healthy subjects (data adapted from Heilbronn. 2005)|
A pros pos exercise, interestingly, none of the 10 subjects who were obviously not used to exercising in the fasted state reported any changes in the rate of perceived exertion. This obviously contradicts observations the anti-fasting faction on the Internet commonly cites as one of the most important reasons not to go on an intermittent fast, for everyone for whom his/her exercise (and some even say cognitive) performance is important. In view of the fact, that, even for me, there is a life beyond the SuppVersity, I will yet have to postpone myth #3, i.e. "Intermittent Fasting Will Ruin Your Physical and Cognitive Performance" to the next installment of the Intermittent Thoughts on Intermittent Fasting series. In the mean time, feel free to leave comments, questions and suggestions as to where this series should be heading on Facebook, Twitter or in the comments area of this page.