Weight loss is a concern vexing many Americans, with some diet plans contending calorie reduction as a means to drop pounds, while others prescribe certain foods only. Researchers writing in the January 11Journal of the American Medical Associationarticle “Effect of Dietary Protein Content on Weight Gain, Energy Expenditure, and Body Composition During Overeating” took up the challenge of examining how low, normal and high levels of protein in the diet affected individuals who were overfed by almost 1,000 calories a day.

“Fat storage was exactly the same with all three levels of protein,” said Dr. George Bray, a diet researcher involved in the study. “That is, it was the calories they ate that affected the body fat they stored.”

The subjects consuming high and normal amounts of protein increased their lean body tissue, so while the low-protein diet produced less weight gain (about half the weight gained while on the other two diets), it resulted in less lean body tissue, leading researchers to conclude the low-protein diet was the worst option of the three. The researchers further concluded calorie consumption was the major factor in a person’s weight gain when overeating, although protein levels did influence what happened to lean body muscle mass. pf