Two randomized controlled trials have shown that portion control at meals and snacks result in weight loss. Since portion control is an important factor in weight management, more research using this strategy is needed.

Five studies have shown that as portion size increases at a meal, energy intake also increases. Despite an increase in energy intake, increased consumption of food is not associated with feelings of fullness. Furthermore, two studies have shown that increased energy intake at one meal does not result in decreased energy intake at subsequent meals, resulting in a significant increase in daily energy intake.

Studies have shown no statistically significant associations between portion size variations and subject characteristics, such as sex and BMI.