Minimum Dietary Essential Amino Acid-to-total Nitrogen Ratio for Whole Egg Protein Fed to Young Men

Abstract

Daily urinary nitrogen excretion was measured for 11 young men fed constant nitrogen intakes, equivalent to 0.36 to 0.54 g protein/kg body wt, which approximated their minimum daily requirement. Whole egg furnished 78.6 to 90% of the nitrogen of the basal diet, and oatmeal and tomato juice the remainder. When the ntirogen of the basal diet was replaced isonitrogenously by a mixture of glycine and diammonium citrate, with each compound supplying equal amounts of nitrogen, a 30% replacement did not significantly alter urinary nitrogen excretion. In 4 subjects, a 40% replacement had no significant effect on urinary nitrogen excretion after initial adaptation. A 50% replacement caused no apparent decrease in dietary nitrogen utilization in one subject. A 30% replacement gave an essential amino acid-to-total nitrogen ratio (E/TN) of 2.16 corresponding to 25% of the total nitrogen furnished by essential amino acids. A 40% replacement gave an E/TN ratio of 1.85 and 21% of the nitrogen from essential amino acids.