Similarities of Carbohydrate Deficiency and Fasting

Abstract

Introduction The fasting subject has elevated ketones,^1-3elevated nonesterified fatty acids ( NEFA),^4,5negative nitrogen balance,^6,7lowered blood suger,⁶salt loss,^7,8water loss, and weight loss.^6,8-10In the fasting man, the glycogen reserves^6,11are soon depleted, and fat and protein fcatabolism supplies the body's caloric needs since new carbohydrate is only available in minimal amount. Thus, at a cellular level, the major characteristic of fasting is limitation of available carbohydrate as an energy source.¹²Since fat and protein are the energy sources in fasting, there should be little difference in cellular metabolism whether the fat and protein come from endogenous or exogenous sources. This study was undertaken to determine the metabolic effects of an exogenous caloric mixture of constituents similar to the endogenous caloric mixture of fasting. Method The subjects in this study were normal healthy volunteers placed on a diet of normal