Compensatory hyperphagia after fasting tracks recovery of liver energy status

Studies using metabolic inhibitors suggest that a reduction in hepatic ATP generates a stimulus that triggers feeding behavior. To investigate the rel ationship between changes in liver ATP and food intake under physiological conditions, we assessed changes in feeding behavior and liver adenine nucle otides during refeeding after 24 h of food deprivation. Deprived rats consu med 14 g of food in the first 3 h of refeeding; the rate of consumption dec lined markedly thereafter for the next 9 h, but remained higher than that s een in nonfasted rats. Fasting produced substantial reductions in ATP, ATP/ ADP, and phosphorylation potential relative to fed levels. Refeeding restor ed liver ATP by 6 h, whereas ATP/ADP and phosphorylation potential did not fully recover until 12 h of refeeding. Restricting food intake during refee ding limited recovery of liver energy status. These results show that liver energy production recovers slowly during refeeding with a time course that parallels the compensatory change in eating behavior. These findings raise the possibility that changes in hepatic energy status play a role in satia tion as well as in hunger. (C) 1999 Elsevier Science Inc. All rights reserv ed.