Many people turn to high-protein foods when trying to lose weight because eating protein-rich meals is commonly believed to make dieters feel fuller, researchers said.
The recent popularity of low-carb, high-protein diets can partially be attributed to the fact that dieters often feel fuller when protein intake is high, even if they are consuming fewer calories overall.
Researchers, including Jaapna Dhillon from the Purdue University in US, conducted a systematic review of the evidence on the effect of protein intake on perceived fullness and confirmed that protein does, in fact, make us feel fuller.
"But individual studies are often conducted in small populations or with different approaches that can make interpretation of results challenging. Our study combined multiple experiments to confirm the presence of an effect," Mattes said.
The researchers used a variety of statistical approaches to make sense of the data. The analysis indicated that higher protein loads have a greater effect on fullness than lower protein loads.
With the confirmation that protein intake is related to satiety, defined as fullness between meals, modestly higher protein intake may allow individuals to feel fuller between meals.
"Feelings like hunger and fullness are not the only factors that influence intake. We often eat for other reasons," said Mattes.
"Anyone who has ever felt too full to finish their meal but has room for dessert knows this all too well," he said.
"The exact amount of protein needed to prolong fullness as well as when to consume protein throughout the day is not resolved, and our study did not determine this," said Heather Leidy, Assistant Professor at the University of Missouri.
So while the researchers encourage the public not to consume protein to the point of excess, people looking to moderate their energy intake by enhancing the sensation of fullness might consider a moderate increment in protein consumption as a first step.
The study was published in the Journal of the Academy of Nutrition and Dietetics.