Abstract
In order to compare the plasma amino acid ratio recommended by Whitehead plasma tyrosine and valine levels and the Phe/Tyr ratio with those of healthy children, 24 subjects of 2-4 years old from 3 districts in Iwate Prefecture were selected. The children in these districts were in a sub-optimal state of protein nutrition as is evident from their detardation of growth, especially in Iwaizumi district where more than 15% were below the Japanese standard in body weight. A correlation between those estimations and the change in body weight was observed. The average amino acid ratio in Iwaizumi showed 2.1, whereas in case of healthy children the ratio was 1.7 in average and in the other 2 districts remarkable differences were not observed from that of healthy children.
The amino acid ratio was found to be related to the change in body weight, with a coefficient of -0.75 while the Phe/Tyr ratio and valine content in plasma were somewhat less well correlated with the change in body weight, whereas the tyrosine content of the plasma was only slightly correlated.
The results show that Whitehead's method is simple and widely applicable in field work and may be useful for the early detection of sub-clinical protein deficiency.
