The notion of frequent small meals throughout the day being beneficial for weight loss is perhaps even more pervasive of a dogma than spot reduction in the fitness world. To this very day, you’ll see mainstream, “reputable” fitness publications publishing articles that proclaim the benefits of spreading your daily calories across 5 or 6 meals in order to “stroke your metabolic fire.”
The general thought behind this line of thinking is that by eating more frequently, you’ll boost your metabolic rate using the thermic effect of food (TEF). The TEF refers to the amount of calories your body must use in order to digest the food you eat. Though this amount varies slightly depending on the macronutrient(s) in question (protein, carbohydrate or fat), it can be averaged to about 10% of the total calories than you eat. For example, if you were to eat a meal of 500 calories, it would take your body 50 calories just to digest those calories.
Related Reading: How Many Calories Should I Eat?
The thinking that eating more often must therefore be superior to eating less often comes from a fundamental misunderstanding of the thermic effect of food. The TEF is based on total calories consumed, not on the amount of meals you spread throughout the day. Let’s examine this more closely. Say we have two individuals who both eat 1800 calories per day. One eats these calories spread between 6 meals of 300 calories each. Each meal would have a TEF of approximately 30 calories, for a total of 180 calories per day. The other individual eats their calories across 3 meals consisting of 600 calories per day, producing a TEF of 60 calories, for a grand total of 180 per day. The exact same as the former individual who ate twice as many meals per day.
The inverse is also true. I’m willing to bet you’ve heard the scaremongering rumours about skipping meals before. You know the ones; the ones that say if you don’t eat meals every X number of hours your body will plummet into starvation mode and you’ll start eating away your own muscle in an attempt to stay alive. Yeah, no. Studies show that skipping meals and intense dieting has absolutely no negative effect on your metabolism for at least 72 hours. In fact, a slight (~5%) increase was actually associated with fasting in some studies. The idea that skipping a meal will cause your metabolic rate to slow or cause a loss in muscle mass outside the context of a reduction in total calories is completely nonsensical.
When a Difference in Meal Frequency Matters
As a general rule, it does not matter how many meals you consume per day. The only thing that matters is the total amount of calories you consume in that day – not how you distribute them. Knowing what we now know about TEF, this makes complete sense intuitively. If you were to look collectively at all the food you consume over a years time, it’s a lot easier to see that in terms of its effect on your body composition, the exact timing or distribution of those calories within any particular day simply does not matter, and the research backs that up.
Observational studies have shown that meal frequency can have an effect in terms of your appetite, satiety and how much you eat over that particular day. University of Colorado researchers found that while increasing meal frequency had no significant effect on metabolic rate or the amount of fat burned in a 24 hour period, it did lead to an increase in both hunger and the the desire to eat. It also found that those who ate 3 meals in a day rather than 6 had greater evening and late-night satiety.
However, while this was true for most people, it wasn’t true for everyone. For some, being able to eat more often caused them to avoid snacking and make healthier food choices, therefore helping them maintain a healthy weight. For others, not being able to become full after any given meal due to their relatively small size caused them to be hungry all the time and made it extremely difficult for them to adhere to a meal plan like this for any length of time.
Of course there's also the issue of convenience. For most of us, making time for six meals per day, not to mention actually cooking and preparing them, is simply not feasible. Often times I've seen people completely give up on getting in shape because they've resigned to the fact that they'll never be able to logistically make 6 meals a day work. Don't let yourself fall victim to the 5-6 meal per day dogma!
At the end of the day, how many meals you want to split up your calories into doesn’t matter. Just don’t feel that you need to eat particular number of meals a day to get in shape. Many people have built incredible physiques on 5 or 6 meals a day, and many people have done the same with 3 meals a day or even less.