Comparison of the flux of carbon to hepatic glycogen deposition and fatty acid and cholesterol synthesis on refeeding rats fed ad libitum or meal-fed rats with a chow-diet meal.

Meal-fed rats and rats fed ad libitum had similar rates of hepatic glycogen deposition on refeeding with a chow meal. In contrast, the rate of hepatic lipid synthesis (cholesterol plus fatty acids) was 6-fold higher on refeeding in the meal-fed group compared with the 'ad libitum' group. There were no significant differences in the gastrointestinal or hepatic contents of glucose or lactate between the two groups. It is suggested that in the meal-fed group exogenous glucose may be directly converted into glycogen, whereas the substrate for lipid synthesis is a C3 unit.