A metabolic unit study was performed to determine the effects of eating higher protein levels than the RDA and weight loss. (Pasiakos, S. M., Cao, J. J., Margolis, L. M., Sauter, E. R., Whigham, L. D., McClung, J. P., Rood, J. C., Carbone, J. W., Combs, G. F., Jr., Young, A. J. Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial. FASEB J. 27, 3837–3847 (2013).) The study:
…assessed body composition and muscle protein synthesis responses to controlled diets manipulating protein intake over a range that spans the current acceptable macronutrient distribution range during short-term Energy Deficit (ED).
The study concluded:
…determined that consuming dietary protein at levels exceeding the RDA may protect fat-free mass (FFM) during short-term weight loss.
In summary, consuming twice the amount of dietary
protein than current recommendations measurably
protects FFM and promotes the loss of body fat during
short-term weight loss, likely through the maintenance
of muscle anabolic sensitivity to protein ingestion.
However, consuming dietary protein at 3 times the
RDA does not appear to confer any additional protective