A popular idea you may have heard is that eating smaller, more frequent meals will “stoke your metabolism,” thereby improving your fat loss results. But is it true? Are smaller, more frequent meals better for your metabolism? Would you see better results if you ate six meals instead of three?
It’s not likely. Most studies have “failed to show that different meal frequencies have different influences on bodyweight or body composition”.  How, then, did the notion come about that eating more frequently is better for your waistline? It can probably be attributed to something called the thermic effect of food.
The thermic effect of food
The thermic effect of food, or TEF for short, is the increase in energy expenditure above your basal metabolic rate that results from the digestion, absorption and storage of the food you eat. In other words, your body uses calories to break down food after you eat it. TEF is the smallest of the three components of daily energy expenditure, being comprised of about 10% of the calories you eat. 
The most important driver of TEF is the calorie content of your diet. In other words, the more food you eat, the higher your TEF. It’s important to note, however, that exceeding your daily calorie needs in an attempt to increase TEF is not a good weight loss strategy. Sadly, the math just doesn’t work in our favor on that one.
The second most important factor is the macronutrient composition of your diet. In other words, how are the calories in the food you eat divided between protein, fats and carbohydrates? Protein, for example, takes more energy to digest than carbohydrates (which rank second in thermic effect), or fat (which has virtually no thermic effect).
Assuming that your total daily caloric intake is the same, how frequently you eat has little to no effect on TEF. To illustrate what I mean, let’s compare two scenarios.
In the first scenario, let’s say that you eat 1,800 calories per day, divided into 3 meals of 600 calories each. In the second scenario, let’s say that you eat that same 1,800 calories per day, but divided into 6 meals of 300 calories each. Recall that we’re estimating TEF at around 10% of total calories.
3 MEAL SCENARIO
600 calories per meal * 0.10 = 60 calories per meal spent on TEF
60 calories per meal * 3 meals = 180 calories per day spent on TEF
6 MEAL SCENARIO
300 calories per meal * 0.10 = 30 calories per meal spent on TEF
30 calories per meal * 6 meals = 180 calories per day spent on TEF
As you can see, each scenario results in the same TEF value. By eating smaller, more frequent meals you will “stoke your metabolism” more times per day, but each “stoke” will have a smaller impact.
Conversely, eating larger, less frequent meals will “stoke your metabolism” less often, but each “stoke” will have a bigger impact. At the end of the day, either scenario gets you to the same result.
What about building muscle?
If you’re looking to build bigger muscles, or to maintain muscle mass during a diet, there is probably a benefit to spreading out your protein feedings across several meals. Having said that, you don’t need to slam a protein shake every three hours to protect your gains.
Where optimizing lean body mass is concerned, three protein-rich meals are likely preferable to one or two. According to Brad Schoenfeld, Ph.D., CSCS, “consumption of at least 3 meals spaced out every 5 to 6 hours would seem to be optimal for keeping protein synthesis continually elevated and thus maximizing muscle protein accretion.” 
So how many meals is best?
In general, something between three and five meals is probably going to work well for most people. Still, a range of meal frequencies can work just fine, and there is no one-size-fits-all answer. Some people like three squares, while some people are grazers, while others do well with intermittent fasting. At the end of the day, it may help to ask yourself what’s realistic for you.
Are you constantly chasing after small kids, running errands, cleaning, working, and having trouble finding any time for yourself at all — never mind the time it would take to consistently prepare, pack and eat six meals? Then it sounds like six meals may not work for you. What about three meals? Would that fit into your schedule and keep you satisfied?
Or maybe you find yourself ravenous, tired and cranky between meals when you try to stick to three squares? If you eat too infrequently, do you tend to overeat later on? In that case, perhaps you could eating try four meals instead of three — or even five, or six. They don’t even need to be uniform in size. Maybe you’d do well with two to three larger meals, plus a smaller snack or two?
Ultimately, go with a meal frequency that fits with your lifestyle, as well as manages your hunger and energy levels. Experiment as needed. Figure out a number of meals that keeps you satisfied, and that you can stick with for the long haul.
Focus on what matters
The secret to long-term physique change lies not in small details, but in the ability to consistently do the important things. So make sure that you have the following things in order first:
- Eat the right number of calories for your goal
- Make sure your protein intake is sufficient
- Eat at least 80% nutritious whole or minimally-processed foods
- Get enough sleep, and address stress if needed
- Strength train in a progressive fashion
Then do these things over and over. I promise that if you do the above things consistently, they will take care of most, if not all, of your results. As for meal frequency? Do what works for you.
- Eric R Helms, Alan A Aragon and Peter J Fitschen. “Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation.” Journal of the International Society of Sports Nutrition (2014) 11:20, p. 8.
- Klaas R. Westerterp. “Diet induced thermogenesis.” Nutrition & Metabolism. (2004): 1-5, p. 3.
- Brad Schoenfeld, Ph.D., CSCS. “Are Frequent Meals Beneficial for Body Composition.” LookGreatNaked.com, the Official Site of Brad Schoenfeld. 25 January 2015. [Accessed 20 January 2017]
- Paul M LaBounty, et al. “International Society of Sports Nutrition position stand: meal frequency.” Journal of the International Society of Sports Nutrition (2011) 8:4.