To measure the effect of a high-protein diet and heavy weight lifting, researchers recruited 48 adults with resistance training experience and assigned them to a diet where they consumed either 2.3 grams or 3.4 grams of protein per kg of body weight daily. Findings were published in Journal of the International Society of Sports Nutrition.
All subjects tracked progress in a split-routine periodized heavy resistance training program along with dietary intake in a journal. They trained 5 days a week. After 8 weeks, the 2.3 gram per day group gained an average of 1.3 kg in body weight while subjects on the higher protein diet lost a small amount of body weight and more fat mass than lower protein subjects despite consuming significantly more calories. Improvements in one rep max strength, vertical jumps and pull ups were similar between groups.
True Strength Moment: If you weigh 180 pounds, you’d be consuming 188.5 grams of protein daily on the lower protein diet described in this study, and 278.8 grams per day on the higher protein diet. For some perspective, your average chicken breast yields about 30 grams of protein. It is possible to get much of a good thing.