Nitrogen retention of young men who consumed selection patterns of essential amino acids at a constant nitrogen intake.

Six patterns of essential amino acids were devised to represent different sources or combinations of protein based on a daily intake of 6.0 g of nitrogen from these sources.In each diet,cerealsfurnished 70% and a specially designed amino acid mixture 30% of the total nitrogen. Nitrogen retention of young men who consumed amino acids equivalent to combinations of rice and soy or egg and potato did not differ from the pattern of egg, and these patterns were superior to a combination of rice and wheat; egg also was superior to corn plus beans and wheat plus milk. Relative amounts and proportions of essential amino acids could be modified without depressing nitrogen retention until one amino acid became limiting or the pattern became imbalanced. Therefore, more than one pattern of amino acids should be recognized as useful for adult human subjects; both minimal and total amounts of essential amino acids need to be considered. Am. J. Clin. Nutr. 31: 786-793, 1978. Protein synthesis occurs only when appro- priate quantities of amino acids are present at a particular site. Utilization of dietary proteins, therefore, is influenced by both specific amounts of essential amino acids and the proportions in which they exist. The goal of improving protein quality by com- bining with other proteins or supplementa- tion with particular amino acids is to achieve a pattern of amino acids that maximizes efficiency of utilization.