A study published in The American Journal of Clinical Nutrition shows that dieters who eat more protein might lose a bit more weight than those who get less protein and more carbohydrates.
The researchers analyzed 24 past trials that included a total of 1,063 people. Participants were all put on a reduced-calorie, low-fat diet designed to help them lose weight. About half were prescribed a high-protein version of that diet—containing about 85 g of protein per day for a 150-lb person—and the other half a standard-protein diet, with 49 g per day, on average, for a 150-lb person. Across all trials, high-protein and standard-protein diets were designed to provide the same calorie reduction. Depending on the study, participants lost an average of anywhere from 2.4 to 25.1 lbs.
The researchers found that over an average of 12 weeks, people assigned at random to a high-protein diet lost about 1.8 extra lbs, and more body fat, than those assigned to a standard-protein diet. There was no difference, however, in how much participants’ blood pressure, cholesterol levels, or markers for diabetes risk changed based on the protein content of their diets.
The researchers are unclear why a higher protein-to-carbohydrate ratio might help people shed more pounds, and more studies need to be conducted.