OBJECTIVEThis study is to examine the influence of familiarity on energy intake, eating behavior, and concentration of the plasma gut hormones in lean and overweight young male subjects.

METHODSTwenty-eight lean and twenty-eight overweight participants were recruited. Their food consumption was documented and analyzed when they had a test meal while they were paired with friends or strangers at the same weight stature. Their eating behavior was recorded with cameras hidden in the carton, and postprandial plasma gut hormone concentration were measured.

RESULTSCompared with overweight strangers (OS), overweight friends (OF) had increased food consumption, prolonged and decreased number of chews per 10 g food. Compared with OS, postprandial plasma concentration of cholecystokinin-8 was significantly lower in OF group at 30, 60, and 90 min, whereas the concentration of glucagon-like peptide 1 was significantly lower at 60 and 90 min. Plasma ghrelin concentration was significantly higher in the OF group than that in the OS group at 90 and 120 min. No significant differences in gut hormone concentration were observed between lean strangers (LS) and lean friends (LF) groups at all time points.

CONCLUSIONFamiliarity plays an important role in increasing energy intake and in changing of postprandial gut hormone concentration in overweight individuals.