The relationship of carbohydrate metabolism to protein metabolism

Abstract

Studies on adult human subjects show that when the protein and carbohydrate moieties of an adequate diet are separately ingested over short periods of time, there is a negative N balance of some 2g. daily (mainly as urea). This loss is equally distributed between the day and night urine excretions. There is a corresponding loss of S which, however, is confined to the day urines. Creatinine excretion is relatively unaffected by this procedure. The association of a small fraction of the dietary protein with the carbohydrate is sufficient to maintain N equilibrium. When carbohydrate is ingested over a sufficiently long period in excess of energy requirements a storage of N and S results no matter whether the carbohydrate be taken along with, or apart from, the dietary protein. The variation in the number of meals in a fixed diet from 8 to 2 causes a transitory loss of N due to the disturbance in time relationships. This procedure does not affect the digestibility and absorbability of the protein and fat of the diet.