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Scientific Basis for Tenets of Diet?


So, it is widely believed that eating calories late at night leads to weight gain. Is it because you had already eaten your calories during the day so these are excessive calories or is it some type of late night process?

I looked at two different studies: one suggested that there was no difference in weight gain and another showed a minimal gain - but in that study, there was a major confound. Now, I have read that triglycerides are higher if you sleep after you eat and your insulin levels and metabolism could go down. So, this means that one should just make sure to move around after eating late at night; don't sleep right after eating.

But does anyone have different research or evidence on this?

Another tenet is the belief that one should eat multiple small meals throughout the day. If the reason one should do this is to avoid starvation mode and to bolster the metabolism, then how much of an effect does food really have on the metabolism? I read this:

Lyle McDonald had this to say in summarizing meal frequency:
"TEF (Thermogenic Effect of Food) differs for the different nutrients, on average it constitutes about 10% of a typical mixed diet. So every time you eat, your metabolic rate goes up a little bit due to TEF.

So, all calories have the same effect - regardless of portions or frequencies in which they are consumed. I had also read a study that said that they compared people who had eaten 3 meals a day and people who had eaten 6 meals a day - they ate the same amount of calories - and there wasn't a weight gain difference.

It really seems like, at the end of the day, it truly is just about calories. Does anyone have any research that suggests otherwise?


who still believes eating late at night leads to weight gain, unless you're an Oprah watcher.

Most Americans eat shitty food late at night, shocker

I don't need any evidence, we're not Gremlins, we can eat past midnight and not turn into evil creatures


It says there's a post, but I can't see it. wat


Yup, jehovas. I still hear it spouted all the time, even in the Nutrition/S+C community.


Yeah I always wanted a Mogwai. I agree with JF.


It is mostly about calories for the average person who needs to lose weight. Many people have bad habits snacking at night, especially when they choose high-calorie foods like chips or ice cream. Those foods do also particularly promote fat storage because the carbs raise insulin, and when the body has carbs available for energy, the fat is stored.

But when you have someone who eats a bowl of ice cream and a bag of chips every night not to eat after X PM, that one little rule could eliminate 800 fattening calories from the daily total.

I haven't heard anything about the triglycerides effect.

Insulin levels -- well, people are more insulin resistant in the evening. This was the motivation behind the rule not to eat carbs at night. I am not convinced it matters.

"Metabolism" -- people seem to have all kinds of erroneous ideas that you can so easily make your "metabolism" go up and down. Your body burns certain number of calories for energy at rest. Rest is about the same for using a computer, sitting, or sleeping. REM sleep phase is about 20% lower. Eating a meal will never make the metabolism go down. Any meal requires some energy for digestion.

For the average person to control his WEIGHT, which is what all these studies are about, NO factor matters more than calories at the end of the day.

Even for weight control, diets with more protein will be better because of the high thermic effect of protein, better blood sugar and insulin control, appetite control, and the fact that protein is the last thing the body wants to use for energy.

However, weight control studies are not applicable to bodybuilders or anyone interested in body COMPOSITION. There's a pretty simple logic for eating 6 (or more) meals containing protein throughout the day if you want to GAIN MUSCLE: there's only so much your body can digest and absorb at one time. More small meals means more hours spent in positive nitrogen balance with amino acids available for repair and growth of muscles. This logic has seemed to work for bodybuilders for a long time. If there are any bodybuilders who did as well eating 3 or fewer huge meals per day, I have never heard of it.

When I advise average people (i.e., not bodybuilders) who simply need to lose a bunch of fat, though, I don't think there is a significant measurable advantage for them to eat 6 meals a day unless they have low blood sugar issues. For example, my mom weighs 200 pounds. There is no need to tell her to eat "6 small meals" a day. Getting the protein ratio up would give her an advantage, but ending every day in a deficit is THE MOST IMPORTANT thing.


andersons, thank you for that FANTASTIC post. Your distinction between the average person and a bodybuilder was quite enlightening.

So, if you were advising a person with 150lbs to lose - to get to their ideal body weight - you wouldn't overload them with rules about protein/late night eating/meal frequency, you would just emphasize the calorie deficit. Now, once that person wants to put on muscle and start bodybuilding, then they should eat frequent meals, etc.

Here's another question - since I have your ear - while most people think that they should try to maintain their muscle mass while losing weight, isn't this a myth? If a person is 300lbs and their ideal weight is 200lbs - isn't their lean body mass inflated (220lbs or so) since they had gained so much weight? Doesn't that person actually need to lose muscle, in addition to fat?

I am sure I am just preaching to the choir but many people don't know that when a person puts on 4lbs, 3 of it is fat and 1 is muscle; just like the 3 to 1 ratio in weight loss.

Isn't this right, as well?


I agree with JF, most people eat crap late at night to begin with. Then with this huge influx of calories they go to sleep, which doesn't burn many calories, can you see why this can easily lead to weight gain? If you had a big breakfast, at least you have the rest of the day to burn off some of that food. BTW, sumo wrestlers are told to eat huge meals and then sleep, and we all know how desired their physiques are.



Sorry, but that is just plain wrong. your body will digest everything you put in it given enough time.

Smaller meals = digested faster
Bigger meals = digested slower

but EVERYTHING still gets digested regardless.

Humans evolved to survive in times of plenty and in times of famine, our bodies are smart enough to know not to waste precious energy just because one overeats by (x) amount of calories at a time.

most bodybuilders eat multiple meals throughout the day because its easier to eat a lot of calories doing that than trying to stuff down 4,000 calories in 3 meals. But if they did only do it in 3 meals, the results would be identical to 6 (or 8, or 10, or whatever)

otherwise, good post.


JMo, so are you dispelling the notion that one should only eat a small meal (400cal) because the body can only digest that amount; and if they eat 1000cal, in a meal, 600 will turn into fat?


lol! funny, i've never seen actual numbers attached to that myth.

if someone told me i'd get fat by eating over 400+ calories in a meal, i'd tell them to eat one 1,000 calorie meal per day and see how much fat they gain.

there's a mechanism (if that's the right word) in the stomach (or upper intestine) called the ileal break that stops undigested food from entering the intestine for digestion/absorption until the body is ready to assimilate it. essentially, if you eat a big meal, yor body just lets it sit in the gut until, little by little, its fully digested. a "normal sized" meal (~400-600 calories) will be fully digested in ~5 hours. larger meals may take up to 8 hours or more, depending on the composition of the meal (things like cottage cheese digest slower than, say, dextrose)

larger, less frequent meals = smaller, more frequent meals.

it's when people begin eating larger, more frequent meals that they end up getting fat (i.e. they're eating too many calories)


I tend to agree with JM on this one, but andersons post was eloquently written so I'm thoroughly confused. Do you have any research for the 6 meals a day theory?


Thanks, JMo. I really like this board, you guys are definitely knowledgeable.


Stick with what works.


Related studies show that people who get fat by over-eating at night also over-eat in the morning, afternoon, in the shower and workout less than once a week.


True. The studies on the subject that MaxPower99 refers to are not relevant, due to the subjects that were used. But absence of good evidence in support of smaller meals does not mean that there is not merit to the theory. Until a study comes out that says smaller meals are bad, I'd prefer to stick with the approach commonly supported on this site. You can choose to eat 3 meals per day or even go on the warrior diet. It's your call. Science will catch up to bodybuilding eventually, and prove/disprove it.


are you stupid, or do you just lack basic reading comprehension skills?

nobody said eating smaller, more frequent meals are "bad", just that they don't confer any advantage over less frequent meals (within reason, obviously only eating 1 meal per day wouldn't allow for proper pre/post workout nutrition, and would thus be inferior to a 2-or-more meal set up)

and science has caught up to bodybuilding, and it seems that 3 meal per day MAY have and advantage over 6, although i'd like to see some more studies done. check this out:


Truls Raastad1, Therese Fostervold1, Ã?yvind Hansen2, Ernst Albin Hansen1, Ina Garthe1,3, Per
Egil Refsnes3

Norweigan School of Sports Science, Oslo, Norway; 2Department of Nutrition, University of
Oslo, Norway, Olympiatoppen, Oslo, Norway

Surprisingly the 3 meals/day group increased strength and muscle cross sectional area in upper
body significantly more than the 6 meals/day group. In studies where the acute effect of meals on
muscle protein metabolism is studied, the general conclusion is that each time a minimum of
essential amino acids (6 g) and carbohydrates (30 g) are ingested, muscle protein synthesis is
maximally stimulated for a short time [3]. Hence, we hypothesised that 6 meals/day should be
superior to 3 meals/day, because of a more frequent stimulation of muscle protein synthesis. The
only study in which some support for few and larger meals can be found, is a study on older
women, where a more positive nitrogen balance was observed with a concentrated intake of
protein compared to protein intake equally distributed on 4 meals per day [4]. However, this effect
was not observed in younger adults [5].

We found no beneficial effect of eating 6 meals/day compared to 3 meals/day as long as the total
energy intake and the intake of nutrients is similar and above the requirements. On the contrary
we found indications in favour of 3 meals/day on both strength and muscle mass measurements in
upper body.

[1] Paddon-Jones et al., Am. J. Physiol.Endocrinol. Metab. 288, E761-E7671, 2005.
[2] Iwao et al., Scand. J. Med. Sci. Sports. 6, 256-272, 1996.
[3] Tipton & Wolfe., J. Sporst Sci. 22, 65-79, 2004.
[4] Arnal et al., Am J Clin Nutr. 69 (6):1202-1208, 1999.
[5] Arnal et al., J Nutr. 130 (7):1700-1704, 2000.


Thanks for posting the study. Interesting stuff. Although i appreciate the study I must ask the same question of you: "are you stupid, or do you just lack basic reading comprehension skills?" Where did I imply that anyone said that eating smaller, more frequent meals are "bad?" I simply said that there was an absense of evidence against small meals being detrimental. I was talking about the fact that there is not a study. I didn't quote anyone on this thread, and I think my reading comprehension is just fine, but thanks for asking.


hhmm...I'm not above humility, it seems it is I who needs to bone up on my reading comprehension skills, my bad BulletproofTiger.

to be honest, this whole notion of meal frequency has been hashed and rehashed so many times I'm a little tired of it. If you search there's a whole long flame filled thread about meal frequency somewhere on this board. go there to read more.

but yeah, my point still stands, most diet "rules" turn out to be shit when you actually look at the science.


It's all good. I actually agree with your main point, that "


Shitty "diet rules" tend to come in two flavors. The first being the worst of the two flavors - those which are promulgated by the population's desire to find a scape goat for its health issues, i.e. trying to pin all health and weight problems on dietary fat, and later on carbs, whilst ignoring the real underlying issues that have actually made the impact on health, overstressed, overfed, and under exercised. The second more unique flavor of "diet rules" are applicable to the health community in general and in particular the subset called bodybuilders. The health community flavor of diet rules has a similar flavor to carboard, while the bodybuilding subset has a more "meaty" flavor to it. The rules for these subcategories attempt to more accurately pinpoint a scientific basis for the connection between nutrition and health, and are not subject to as high a degree of misunderstanding.

Personally I don't dislike the "meaty" bodybuilding flavor of diet rules. I think there is some evidence behind some of the diet rules of the bodyuilding community like manipulating macros at different points in the day (there is scientific support for peri-workout nutrition for example), reducing carbs late in the day (at least annecdotal), carb cycling(at least annecdotal), etc. If you want to use these approaches, it's up to you, but I agree that the science behind it is limited.

Perhaps, based on that study, there is limited or no credibility to the 6+ meals per day rule. However, i think we need more reasearch than just the one study to "prove it." Maybe in a bodybuilding setting for example. Eating frequently is helpful if you're bulking though.