In adults, muscle growth, or hypertrophy, is initiated by appropriate training and will manifest with proper rest and nutrition. Calorie and protein needs have to be met, with additional protein made available for the rebuilding of muscle. Inadequate protein and/or caloric intake will negatively affect nitrogen balance, preventing muscle growth.[1,2,3] However, once protein needs are met, the addition of more protein will not stimulate further muscle growth.[4,5] Continued protein intake above needs simply increases the use of protein for energy immediately for activity or stored as fat for later use.
1 Nordmann AJ, Nordmann A, Briel M, Keller U, Yancy WS, Brehm BJ, Bucher HC. Effects of Low-carbohydrate vs. Low-fat Diets on Weight Loss and Cardiovascular Risk Factors, A Meta-analysis of Randomized Controlled Trials. Ann Intern Med. 2006;166:285-93.
2 Wadden TA, Phelan S. Behavioral assessement of the obest patient. In: Wadden TA, Stunkard AJ, eds. Handbook of obesity treatment. New York: Guilford Press, 2002;186-226.
3 Dansinger ML, Tatsioni A, Wong JB, Chung M, Balk EM. Meta-analysis: the effect of dietary counseling for weight loss. Ann Intern Med. 2007 Jul 3;147(1):41-50. Review.
4 Tarnopolsky MA, Atkinson SA, MacDougall JD, Chesley A, Phillips S, Schwarcz HP. Evaluation of protein requirements for trained strength athletes. J Appl Physiol. 1992 Nov;73(5):1986-95.
5 Walrand S, Short KR, Bigelow ML, Sweatt AJ, Hutson SM, Nair KS. Functional impact of high protein intake on healthy elderly people. Am J Physiol Endocrinol Metab. 2008 Oct;295(4):E921-8. Epub 2008 Aug 12.
6 Gaine PC, Pikosky MA, Martin WF, Bolster DR, Maresh CM, Rodriguez NR. Level of dietary protein impacts whole body protein turnover in trained males at rest. Metabolism. 2006 Apr;55(4):501-7.