How Much Protein to Prevent Losing Muscle Mass While Dieting?

Research indicates that twice the RDA of protein consumption protects muscle mass and promotes fat loss, while triple RDA of protein consumption does not have any additional benefits.¹

The research challenges the theory that losing muscle mass is inevitable when losing weight by exercising and dieting.

The researchers reveal that twice the RDA (recommended daily allowance) of protein consumption while sticking to an exercise and diet plan helps in preventing muscle mass loss and the promotion of fat loss. However, triple the RDA consumption of protein failed to provide further benefits.

The researchers believe that the RDA for protein ought to be based on a level optimal for health, and also for preventing deficiencies, and the data shows that the current RDA is potentially inadequate for sparing muscle mass when losing weight, which could affect a substantial section of the population.

For the study, young women and men were assigned controlled diets for 31 days providing dietary protein at 3 different levels:

The recommended daily allowance
Twice the RDA
Three times the RDA

For the 1st 10 days participants were provided enough total calories for maintaining constant body weight to enable the adjustment of their metabolism to the level of dietary protein, and then weight loss was induced for the next 3 weeks by the restriction of total calories and sufficiently increasing daily exercise to elicit an average weight loss of 2 pounds a week.

Research staff prepared and administered all meals and exercise was strictly controlled. Muscle protein metabolism and body composition measurements were taken at the finish of both the weight loss and stable weight maintenance stages of the study.

The results revealed that the protective effects of extra protein has its limits. The data indicates an optimal, and maybe maximal, protein level is required for active individuals who undergo short-term periods of weight loss.