Studies on the severity of various amino acid imbalances in the young male rat

Relative severities of amino acid imbalance were compared in young male rats fed diets having an amino acid imbalance with respect to various essential amino acids. In the imbalanced diets, one or more essential amino acids were made to be low, ranging from suboptimal to two times the requirement, while the other essential amino acids were present at three times the requirement. From the extent of depressions in food intake and growth, the severity of amino acid imbalance was found to be dependent upon the level as well as the type of the limiting amino acid(s) in each imbalanced diet. The overall results indicated that Met imbalance was very severe, followed in decreasing order by Ile, Trp, Leu and Val, His, Phe, Thr, Lys and Arg imbalance. The imbalance with respect to the large neutral amino acid appeared to be more severe than the imbalance with respect to the small neutral amino acid, while the imbalance with respect to the basic amino acid was least severe.