Does Meal Frequency Matter?

Of the many diet and lifestyle variables at our disposal, the concept of meal frequency has been debated for quite some time. Meal frequency is exactly what it sounds like – the frequency at which you’re eating your meals throughout the day. This involves another one of those old tips I’m sure we’ve all come across at one point or another – in this case, meal frequency has been thought to “ramp up” your metabolism when dieting. This comes from the idea that if you eat smaller meals more frequently throughout the day, as opposed to fewer, larger meals, you’ll essentially be keeping your metabolism elevated or fired via something called the thermic effect of food (TEF). This is the energy we expend through simply digesting and absorbing the food we eat. This is another variable that is lumped in with other forms of energy expenditure (NEAT, EAT, BMR) that will sum up our total daily energy expenditure (TDEE).

There are studies on meal frequency supporting both sides to this argument, but there are very few that have been done on active and lean populations. With the state of the current obesity epidemic, it makes sense that research would be centered on the population in question, but there is little known about how this dietary component can impact physique enhancement in athletes and even just an active/healthy population as a whole. With that said, it is important to keep in mind that results can very much vary depending on the specific population being studied. The primary study to be discussed involves an obese population, although additional information worth mentioning regarding studies on leaner individuals will help give a tentative idea of how and if meal frequency makes a difference in body composition and overall progress.

The study

The primary concern of this study was to determine whether or not a higher meal frequency proved to be superior for weight loss compared to a lower meal frequency. 18 obese men and women (16 of whom ended up completing the study) were randomized into two dietary treatment groups: a high meal frequency (MF) which consisted of 3 meals + 3 snacks/day, and a low MF consisting of just 3 meals per day. The subjects were also sedentary individuals and had not undergone any significant weight changes within the past 6 months leading up to the study. While there are more markers that will differ between the overweight/obese and the more active, weight regulation is a variable that can most definitely apply to anyone, regardless of their dieting history and/or current health status.

Dietary details

The subjects in each diet group were prescribed hypocaloric intakes creating roughly a ~700 calorie deficit. The men and women were stratified equally among the two study groups and adhered to meal plans that were provided to them, each of which followed recommendations from the Canadian Diabetes Association.

As for structuring meals throughout the day, a period of 4 hours minimum to 6 hours was suggested between mealtimes for both high and low MF groups. Additionally, the final meal of the day was to be consumed at least 3 hours before bedtime (or at least 2 hours for snacks with the high MF group).

One difference within the high MF group noted is that snack times were specifically given to the subjects based on their average level of fullness post-meal (via finding their “fullness peak” using a visual scale). As all subjects were given a caloric deficit to follow, the total calorie content of meals and snacks were adjusted for the high MF group in order to account for those possible discrepancies in total intake due to the added frequency.

Key Findings

Over 8 weeks of dieting, a 4.7% drop in body weight was achieved across both diet groups. Fat mass, lean body mass, and BMI were significantly decreased as well. Regarding total body weight loss, there were non-significant differences between both diet groups, so both groups experienced similar decreases in weight after the dieting period. As for fat mass, lean body mass, and BMI, there were also no major differences seen between the high and low MF groups concerning the decreases in these variables.

An interesting measure taken into account was the appetite of the subjects. It would be assumed that undergoing a higher meal frequency would impact pre-meal ghrelin levels and the subjects’ pre-meal appetite ratings in a way that would promote greater dietary adherence. This makes sense in that having fewer meals closer together could better manage one’s appetite (as we all know going into a meal starving is a recipe for disaster… or just eating more than we need to). The researchers actually found that meal frequency did not end up changing any appetite parameters for better or for worse.

Overall, when calories are equated and accounted for, imposing a high meal frequency does not show to improve or enhance weight loss in obese, sedentary individuals. We can achieve the same degree of fat loss and body weight regardless of how we choose to time meals throughout the day, as calorie balance continues to reign as the much more important factor to keep control over if you are looking to improve your body composition.

What about athletes?

Unfortunately, this is an area of study that is also lacking within athletic and leaner populations. With that said, the principle of calorie balance still applies to those who are more athletic, as performance can be greatly impacted by body composition depending on the sport and the demands it places on the athlete. The International Society of Sports Nutrition does state, however, that if meal frequency were to have any kind of impact on enhancing one’s body composition, it would most likely happen to athletic populations, and not in the sedentary. This can simply be due to the multitude of variables at play once training and activity are thrown into the equation – some being anabolic stimuli and nutrient timing. Nevertheless, more research needs to be conducted in this population order to better understand the relationship between meal timing and the competitive athlete.

References

1. Cameron, J.D., Cyr, M., Doucet, E. Increased meal frequency does not promote greater weight loss in subjects who were prescribed an 8-week equi-energetic energy-restricted diet. British Journal of Nutrition (2010), 103; 1098-1101.
2. La Bounty, P. M., Campbell, B.I., Wilson, J., et al. International society of sports nutrition position stand: meal frequency. Journal of the International Society of Sports Nutrition (2011), 8:4.