Abstract Background Bile acids (BAs) play important roles in glucose regulation and energy homeostasis via G protein–coupled receptors, such as enteroendocrine L cell TGR5. The aim of the present study was to investigate the relationship between postprandial BA levels and body composition after ingestion of a standard test meal. Methods Eleven healthy subjects of normal weight (body-mass index, 22.0±1.6kg/m2 [mean±SD]), ingested a 400-kcal test meal, and blood samples were obtained from them before ingestion and every 30minutes for 120minutes after ingestion. The BA fractions were measured with high-performance liquid chromatography. To evaluate body composition, body impedence analysis was performed 1hour before ingestion of the test meal. Results Concentrations of both total BA and total glycine-conjugated BA (GCBA) at 30, 60, 90, and 120minutes after test-meal ingestion were significantly higher than those at baseline. The body-mass index was correlated with total GCBA at baseline. Moreover, body fat mass was correlated with total GCBA at 30minutes (r=–0.688, P=0.019) and 60minutes (r=–0.642, P=0.033) and with total BA at 30minutes (r=–0.688, P=0.019) and 60minutes (r=–0.642, P=0.033). Conclusion The postprandial BA response is inversely related with body fat mass in healthy subjects of normal weight.