Hepatic balances for glucose and its precursor, lactate, were calculated by measuring hepatic blood flows and the arteriovenous differences of these metabolites in 2 groups of overweight rats: cafeteria diet-fed rats and post-cafeteria rats. Obese rats show abnormal hepatic glycogen handling, since they do not mobilize all hepatic glycogen stores after 24-hour starvation, in a situation in which a lower rate of hepatic glucose output and a higher capacity for lactate uptake are attained. The important decrease (about 50%) in the hepatic blood flows observed in post-cafeteria rats versus control rats was similar to that caused by 24-hour starvation in control animals, suggesting that after withdrawal of the cafeteria diet, the liver blood flow of the post-cafeteria rats was adapted to the low-food intake in order to make better use of the energy consumed. The results also suggest an increased efficiency of hepatic lactate uptake in post-cafeteria rats.