Many people turn to high-protein, low carbohydrate foods as they attempt to lose weight, with the belief that protein-rich meals help dieters feel fuller, causing them to eat less, and hence lose weight.

A new study published in The Journal of Human Nutrition and Dietetics has found that may in fact be the case. Up until now, the theory had not been tested on a large scale. 

The study was lead by Richard D. Mattes, MPH, PhD, RD, Distinguished Professor, Department of Nutrition Science, Director of Public Health, and Director of the Ingestive Behavior Research Center at Purdue University. His team combined multiple experiments to confirm a true effect.

The team of researchers searched multiple databases for studies that evaluated the effect of increased protein on fullness ratings. Using a variety of statistical approaches to make sense of the data, they used a quantitative meta-analysis and secondary directional analysis using a vote counting procedure. They say both the meta-analysis and directional analysis indicated that higher protein loads have a grater effect on fullness than lower protein loads.

Dr. Mattes explained, “With the confirmation that protein intake is related satiety, defined as fullness between meals, higher protein intake may allow individuals to feel fuller between meals.”

Yet, while protein may help dieters feel fuller, he says, it's not a magic bullet. “Feelings like hunger and fullness are not the only factors that influence intake, we often eat for other reasons,” he noted.

Fellow researcher, Dr. Heather Leidy, Assistant Professor with the Department of Nutrition & Exercise Physiology at the University of Missouri said it was important to note that the precise amount of protein needed to prolong fullness as well as when to consume protein throughout the day, was not determined.  She cautioned that people looking to moderate their energy intake by enhancing the sensation of fullness might want to consider a modest increase in protein consumption as a first step.

Dr. Mattes noted that this study did not specifically evaluate dieters or fitness buffs in particular, who are often fond of increasing their protein-rich foods such as meat, fish and plant-based proteins, when trying to shed excess pounds. But it does seem to suggest that if these short-term effects are sustained over the long-term, increased protein intake may aid in the loss or maintenance of body weight.