Reassessment of Amino Acid Requirements of Young Women on Low Nitrogen Diets

Abstract
Young women served as experimental subjects in a series of experiments in which the lysine and tryptophan requirements were studied. With a daily nitrogen intake of approximately 5 g it was found that the requirements for both lysine and tryptophan were in the range of 50 mg/day. These requirement levels are considerably lower than those reported in earlier studies. It is suggested that the difference may be explained by the lower level of the other essential amino acids provided in the present experimental diets, in comparison with earlier studies. It is further pointed out that these low requirement levels, particularly for lysine, are in line with the low lysine maintenance requirements for adults of other animal species.