Metabolism Boost

Now, all of the above is only looking at the quantity of weight loss, not the quality. For athletes and dieters, of course, sparing lean body mass and losing fat is a bigger goal than how much weight is actually lost. Which brings me to the boxer study that everybody loves to cite and nobody seems to have read (except me as I spent years tracking down the full text of the paper).

In this study, boxers were given either 2 or 6 meals per day with identical protein and calories and examined for lean body mass lost; the 2 meal per day group lost more lean body mass (note: both groups lost lean body mass, the 2 meal per day group simply lost more). Aha, higher meal frequency spares lean body mass. Well, not exactly.

In that study, boxers were put on low calories and then an inadequate amount of liquid protein was given to both groups and the meals were divided up into 2 or 6 meals. But the study design was pretty crappy and I want to look at a few reasons why I think that.

First and foremost, a 2 vs. 6 meal per day comparison isn’t realistic. As discussed in The Protein Book, a typical whole food meal will only maintain an anabolic state for 5-6 hours, with only 2 meals per day, that’s simply too long between meals and three vs. six meals would have been far more realistic (I would note that the IF’ing folks are doing just fine not eating for 18 hours per day).

Additionally is the use of a liquid protein that confounds things even more. Liquids digest that much more quickly than solid foods so the study was basically set up to fail for the low meal frequency group. They were given an inadequate amount of rapidly digesting liquid protein too infrequently to spare muscle loss. But what if they had been given sufficient amounts of solid protein (e.g. 1.5 g/lb lean body mass) at those same intervals? The results would have been completely different.

As discussed in The Protein Book in some detail, meal frequency only really matters when protein intake is inadequate in the first place. Under those conditions, a higher meal frequency spares lean body mass. But when protein intake is adequate in the first place (and again that usually means 1.5 g/lb lean body mass for lean dieters), meal frequency makes no difference. And that’s why the boxer study is meaningless so far as I’m concerned. An inadequate amount of liquid protein given twice per day is nothing like how folks should be dieting in the first place.

The thing is, the thermic effect of food is directly proportional in both intensity and duration to the size of the meal. Thus a large meal will have a larger thermic effect which lasts longer while a smaller meal will have a smaller thermic effect which will last a shorter period of time. When the total calculations for the day are made for the same food between the two ways of eating the net effect is exactly the same. If small meals help you keep on track, good for you, if I eat a bunch of small meals I tend to want to overeat because these small meals just don't satisfy me. I would much rather have a big meal. When I actually say the articles on the American Journal of Clinical Nutrition among others it was a comfort to know I could eat the way that works best for me and not be giving up on the supposed metabolism boost of 6 small meals.

I will have to look it up again, but there are several studied done recently on meal timing and all of them point to the same thing, when you eat does not matter. They did everything from one meal a day to several meals a day. In 2007 Stote et al in the A Journal of Clinical Nutrition did a study of people half the group eating one meal a day (dinner in early eveing). The other half did three meals a day. After the test time they let the whole group eat as they normally would for 11 weeks to normalize their eating pattern, then the switch the groups around. The study time was 8 weeks, and they were eating enough to maintain their body weight. The results, 3 meals a day no change in weight. 1 meal a day lost 3 pounds and an average of 4.6 pounds of fat (probably because it is difficult to eat all your calories in one meal). That is not old science, it is recent. When you eat makes no difference. See also Smeets et al British Journal of Nutrition 2008 finding no metabolic rate change between 2 or 3 meals a day; and Farshchi et al Am Jrnl of Clinical Nutrition 2005 using 3, 6 or 9 meals a day again finding no change in metabolic rate.

The multiple meals a day may help you feel more satisfied, it may, but it will do nothing to significantly increase your calorie burning. I believe the numbers for calories burned for 100 calories of protein is like 10. You would be better off not eating that rather than thinking eating something will help you lose weight.

As Parks et al say in their article in the Am Jrnl of Clinical Nutrition, "Simply put, the question of whether there is a health benefit from the consumption of multiple small meals will ultimately depend on how much energy is consumed, as opposed to how often or how regularly one eats."

In short, whatever works for you. For me 3 big meals helps me keep my calories in check better than 5-6 small meals. I am seriously considering the leangain.com approach along with Eat Stop Eat for cutting up once I get to my goal because that style of eating work for me. I know full well it doesn't work for others, but I don't want someone thinking it makes any difference in total daily metabolism unless it can be shown in actual clinical studies.

Just to clarify on the peppers, the boost from the capsasin is not huge, none of them are, I think is was something like 50 calories a day which may not even continue as your body adapts to it effect. Metabolism is not really meant to change a whole lot, when it does it is usually a sign of disease.