One meal, two meal, three meal, more?

The first law of thermodynamics states that energy is not created nor destroyed, but rather, it changes form. In the world of body weight regulation, this translates roughly to calories in vs. calories out, signifying that changes in body weight are dependent on imbalances between the amount of energy entering the body and the amount of energy leaving the body. There is no doubt that one must maintain a caloric deficit to lose weight, but to stop there would only scratch the surface.

Various nutritional and environmental factors can influence energy storage or expenditure within the context of the first law of thermodynamics. For instance, resistance training can help partition a portion of excess calories towards muscle growth rather than fat storage. Consumption of protein is not only necessary for muscle growth, it is also more thermogenic than carbohydrates or fats. Moreover, intense exercise training attenuates the detrimental metabolic effects of overfeeding, and also leads to greater fat loss when compared to no exercise.

Another suggested method of optimizing body composition outcomes is meal frequency. The idea that eating small, frequent meals enhances fat loss and aids in weight management dates back to the classic skinfold thickness^[1] data of 379 Czechoslovakian men published in The Lancet in 1964. Since then, observational data has supported the relationship between eating frequency and obesity risk. Proposed mechanisms for the benefits include appetite^[2] regulation, improved glucose tolerance^[3], and the thermic effect^[4] of the meals. Additionally, increased meal frequency has been shown to play a crucial role^[5] in the anabolic responses to resistance training.

Despite an apparent theoretical basis, studies assessing the relationship between meal frequency and body composition have conflicting results, perhaps from differences in the study populations and procedures. Thus, the current study was a meta-analysis aimed at pooling the outcomes of these studies together so as to provide clarity on the relationship between meal frequency and changes in fat mass and lean body mass.

There have been many studies done to determine the effect of meal frequency of weight management. The study under review is a meta-analysis, meaning researchers pooled data from previous studies to determine correlation and other relationships.