PLASMA LEPTIN AND HUNGER RATINGS IN HEALTHY HUMANS

Leptin, the ob gene product, is considered as a signal involved in the regulation of energy stores through centrally mediated effects on ing estive behavior and metabolism. To investigate the relationships betwe en appetite-related sensations and circulating leptin in humans, 12 he althy male volunteers were served two test lunches (1200 kcal, 38% car bohydrate, 50% fat, 12% protein) with comparable palatability but resu lting in different postprandial hunger ratings, and plasma leptin conc entrations were monitored during 8 h after meal ingestion. Whereas pos tprandial hunger ratings (assessed by visual analog scales) and plasma insulin patterns differed significantly between meals, no significant difference in postprandial plasma leptin concentrations was observed between the two meals. A moderate but significant increase in mean pla sma leptin was found over time. We conclude that postprandial plasma l eptin concentrations do not significantly differ between two meals ind ucing different effects on hunger subjective feelings. These data are in agreement with a role for leptin in the regulation of energy balanc e as a long-term adiposity-related signal rather than a short-term mea l-related factor. (C) 1998 Academic Press Limited.