INFLUENCES OF BODY-WEIGHT, BODY-COMPOSITION, AND SUBSTRATE OXIDATION RATE ON RESTING POSTABSORPTIVE GLUCOSE-PRODUCTION AND GLUCONEOGENESIS

OBJECTIVE: To determine the influence of body weight, fat mass, and fa t distribution on resting endogenous glucose production in healthy lea n and overweight individuals. DESIGN: measurements were performed in t he resting postabsorptive state in individuals receiving an unrestrict ed diet. SETTING: Institute of Physiology of Lausanne University. MEAS UREMENTS: resting post absorptive glucose production, glycogenolysis a nd gluconeogenesis; resting energy expenditure and net substrate oxida tion. RESULTS: Endogenous glucose production was positively correlated with body weight, lean body mass, energy expenditure and carbohydrate oxidation. Gluconeogenesis was positively correlated with net lipid o xidation and energy expenditure, and negatively correlated with net ca rbohydrate oxidation. No correlation with body fat or fat distribution was observed. CONCLUSIONS: Gluconeogenesis shows a large interindivid ual variability Net lipid oxidation and not body fat appears to be a m ajor determinant of gluconeogenesis.