In recent years, many have supported and encouraged the belief that eating smaller, more frequent meals is better than eating larger but less frequent meals. The idea behind this is that it better controls your appetite, reduces the rapidity of blood sugar spikes, and most importantly, increases your metabolic rate. However, these claims have since been proven scientifically incorrect.
The claim that eating more frequently improves your overall feeling of fullness has been proven wrong by a study conducted at the University of Missouri, where results show that after 12 weeks of dieting to lose weight, meal frequency (3 vs 6 meals per day) had no effect on appetite control, whereas an increase in protein intake did (1). Moreover, at the University of Kansas, a study concluded that surprisingly, eating 6 meals a day resulted in generally lower levels of satiety than eating just 3 (1).
The argument that eating more often balances blood sugar levels is based on the thought that bigger meals cause a more drastic blood sugar rollercoaster effect. However, this argument has been refuted by a study conducted at the Maastricht University Medical Center (2). Although it is true that bigger meals may cause bigger blood sugar spikes, people who eat fewer, larger meals have a lower overall blood sugar level and blood glucose than those who eat smaller, more frequent meals.
Lastly, many believe that eating every few hours helps your metabolism stay at a constantly elevated level and thereby increasing your overall energy expenditure. However, scientists at the French National Institute of Health and Medical Research, after comparing the metabolic effects of eating patterns from eating 1-17 meals a day, concluded that although small meals did cause a metabolic increase, those increases were small and didn't last very long (1). Large meals, on the other hand, caused larger increases that lasted for longer. Therefore, over a 24-hour period, the overall energy expenditure had no significant difference between varying eating patterns (1).
(1) Bigger Leaner Stronger: The Simple Science of Building the Ultimate Male Body by Michael Matthews