The correlation between excess calories and excess urinary nitrogen in the specific dynamic action of protein in animals

Several years ago it was pointed out that after the ingestion of proteins or amino acids a definite correlation existed between the calories and urinary nitrogen in excess of the basal(1) The data used were those obtained by Rapport,(2) Weiss and Rapport(3) and Rapport and Beard.(4) Aubel and Schaeffer(5) were of the opinion that this correlation bears no relation to the specific dynamic action of protein and amino acids. Their main reason was that the curves of extra calories and extra nitrogen are not synchronous; that the curve of caloric metabolism returns to the basal level before that of the nitrogen.