Independent influences of body mass and gastric volumes on satiation in humans

Background & Aims: We assessed the association of body mass and gastric volumes (fasting and postprandial) with satiation and postprandial symptoms. Methods: Healthy obese and nonobese subjects underwent measurement of caloric intake at maximum satiation; postprandial symptoms were measured with visual analogue scales 30 minutes after a meal. Gastric volume during fasting and after 300 mL of Ensure was measured with technetium-99m single-photon emission computed tomography imaging. We used multiple regression analysis to assess the associations among variables. Results: Among 134 participants (81 women and 53 men), the median age was 26 years (range, 12-58 years), and the median body mass index was 24 kg/m(2) (range, 17-48 kg/m(2)). Increased body mass index, but not height, was associated with delayed satiation (P < 0.003, adjusted for sex). Overweight and obese subjects ingested, on average, 225 +/- 57 more kilocalories (945 +/- 239 M) at maximum satiation compared with normal weight individuals. Increased fasting gastric volume was not associated with body mass index or height, but it was significantly associated with delayed satiation (P = 0.001, adjusted for body mass index and sex). An increase of 50 mL in the fasting gastric volume was associated with 114 +/- 32 kcal (479 +/- 134 M) more ingested at maximum satiation. Increased body mass index was associated with lower fullness scores 30 minutes after a meal (P = 0.0012, adjusted for sex and volume of Ensure ingested). In contrast, scores of postprandial bloating and pain were higher with increased body mass index (both P < 0.05, adjusted for sex and volume of Ensure ingested). Conclusions: Greater body mass index and fasting gastric volume are associated with reduced satiation. Increased body mass index or height was not associated with greater gastric volumes.