You’re struggling to force this last bite of your kale salad down. “I need to eat more meals if I’m going to lose weight”, you remind yourself. You gulp your 4th meal down for the day, confident that you’ve kept your body’s metabolism burning at peak levels. Yet, when you step on the scale, you may notice the scale doesn't move. What gives?
Well, here’s a little secret. Eating more meals per day doesn’t increase your metabolism.
The popular myth that more meals increase your metabolism is based on a misunderstanding of the thermic effect of food (or TEF). The TEF is the increase in your metabolism after eating. Some people theorized that if your metabolism increases after one meal, then eating more meals must increase your metabolism much more! Unfortunately, this isn’t the case.
The TEF is proportional to the calories present in the meal (and is affected by the macronutrients in said meal). Assuming the meals are made up of the same proportions of food, then there is no difference in TEF between 3 meals and 6 meals!
Worse yet, eating many small meals may actually make it harder to stay on your diet! One study examined the effect of 3 meals vs 6 meals on fat burning, hunger levels, and perceived fullness. Researchers studied subjects after giving them 3 meals per day and then 6 meals per day over the course of 4 days each. The 3 meals per day and 6 meals per day plan were matched for macronutrient content (proteins, carbs, and fats) and calories. The researchers noted no difference in fat burning between the two groups. However, researchers found that those who ate 3 meals per day reported feeling more hungry and wanting to eat more after their meals. That means that they received no fat loss benefit from multiple meals, but were less full despite eating the same amount of food over the whole day! (Here is a link to the study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4391809/)
In fact, eating more meals per day can be worse for weight loss if you aren’t keeping track of your calories! All weight loss is governed by calories in vs calories out. If you are eating more meals per day and aren’t strictly watching your intake, it is easy to overeat. Even healthy foods like olive oil pack a surprising 120 calories per tablespoon. Add one tablespoon to 6 meals and you’re talking about an extra 720 calories a day! That can easily put you above your calorie needs, making you more likely to gain weight.
Basically, if you like eating more meals per day, great! Enjoy it! If you like eating a few times a day, great! Enjoy it! The best eating plan is the one that fits into your lifestyle. There is no one size fits all and certainly no magic bullet. At least not where meal frequency is concerned.