Effect on Nitrogen Retention of Men of Varying the Total Dietary Nitrogen with Essential Amino Acid Intake Kept Constant

Nitrogen balances of 6 young men on 3 different levels of total nitrogen intake but with identical intakes of purified essential amino acids plus cystine were determined. The essential amino acids plus cystine were given in the same amounts as found in 20 g egg protein. To bring the total nitrogen to the desired level, a solution of diammonium citrate and glycine was used in isonitrogenous amounts. The results indicated that 4 out of 6 subjects showed decreases in nitrogen loss as the daily nitrogen intake was increased from 4.0 to 6.0 g. All 6 subjects showed improved nitrogen retention when the total dietary nitrogen was increased to 8.0 g.