An Evaluation of the FAO Amino Acid Reference Pattern in Human Nutrition

Abstract

Twelve young men were subjects for a study comparing the Food and Agriculture Organization (FAO) amino acid reference pattern and the amino acid pattern of egg as to their effects on nitrogen equilibrium at a constant total nitrogen intake of 10 gm per day. In diet periods wherein the chief source of amino acids was a purified mixture, for both FAO and egg patterns, the nitrogen balance values were not consistently different from diet periods wherein the chief source of amino acids was egg. When the diets were planned according to the FAO or egg patterns with the amino acids proportioned to an equal amount of tryptophan for both patterns, better nitrogen balance was obtained with egg pattern. When the diets contained isonitrogenous amounts of the amino acids according to the FAO or egg pattern, similar nitrogen balance values were found. Reducing the tryptophan content of the diets containing amino acids in FAO pattern proportions by approximately 20% had no effect on nitrogen equilibrium. With either FAO or egg pattern, the total amount of essential nitrogen required in the diet to maintain nitrogen equilibrium in young men under the conditions of this study ranged from 1.0 to 1.3 gm per day.