Leptin is influenced both by predisposition to obesity and diet composition

OBJECTIVE: (1) To investigate whether plasma leptin concentrations differ b etween subjects with and without the genetic predisposistion to obesity, an d (2) to investigate the effect of dietary manipulations on plasma leptin i n these subjects. DESIGN: Easting and postprandial plasma leptin concentrations were measured before and after 14 days' ad libitum intake of a fat-rich (FAT), starch-ri ch (STARCH) or sucrose-rich (SUCROSE) diet. On day 15 ad libitum breakfast and lunch were given and blood sampled regularly until 6 p.m. SUBJECTS: Eight normal-weight, post-obese women and 10 matched controls (bo dy mass index, 23.5+/-0.5 and 22.9+/-0.3 kg/m(2)). MEASUREMENTS: Leptin, glucose, insulin, appetite ratings, dietary intake, b ody weight and composition. RESULTS: Fasting leptin concentration on day 1 or 15 did not differ between post-obese and controls. However, after meal i ntake leptin increased in post-obese compared with controls on all three di ets. In both groups fasting and postprandial leptin concentrations were gre ater after SUCROSE compared with FAT and STARCH. CONCLUSION: A larger postprandial leptin concentration was observed in post -obese subjects than in controls. This may be related to greater insulin se nsitivity in adipose tissue in the post-obese. Furthermore, increased lepti n concentrations were found after a sucrose-rich diet in both groups, possi bly related to larger postprandial insulin peaks on this diet. Both content ions should, however, be validated by further studies.