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September 1963

Similarities of Carbohydrate Deficiency and Fasting: II. Ketones, Nonesterified Fatty Acids, and Nitrogen Excretion

Author Affiliations


From Ferst Research Center, Piedmont Hospital.

Arch Intern Med. 1963;112(3):338-343. doi:10.1001/archinte.1963.03860030092007

Introduction  The fasting subject has elevated ketones,1-3 elevated nonesterified fatty acids ( NEFA),4,5 negative nitrogen balance,6,7 lowered blood suger,6 salt loss,7,8 water loss, and weight loss.6,8-10 In the fasting man, the glycogen reserves6,11 are 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.12 Since 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