CONTRIBUTION OF GASTRIC AND POSTGASTRIC FEEDBACK TO SATIATION AND SATIETY IN WOMEN

Two parallel preload studies were conducted to determine the relative contributions of inhibitory feedback from the stomach and intestine to satiation (meal termination) and postprandial satiety. In the Gastric Emptying Study, five normal-weight women each ingested an egg sandwic h (307 kcal) (1) immediately after a tomato soup preload (120 kcal), ( 2) 20 min after a tomato soup preload, and (3) with no preload. There was 125 g more of soup in the stomach when subjects began ingesting th e sandwich immediately compared to 20 min after the soup, and the empt ying of the sandwich was delayed when it was ingested immediately but not 20 min after the soup. The lag times for emptying of the sandwich were 76.5 (69.1-82.4), 47.2 (20.1-67.7), and 42.4 (17.8-65.1) min for the three conditions, respectively, p < 0.05. In the Food Intake Study , 16 normal weight women ate significantly less (p < 0.01) in test mea ls offered immediately (978 +/- 246 kcal) and 20 min (1027 +/- 298 kca l) after the soup preload than in a test meal with no preload (1151 +/ - 279 kcal). Despite the different amounts of soup in the stomach, sub jects' test-meal intake in the two preload conditions was not signific antly different. Subjects' fullness ratings following the preloads and the test meals were not different among the treatment conditions. The results suggest that feedback from neither the gastric nor the postga stric compartment is primary in determining meal size and postprandial satiety. Instead, signals from gastric and postgastric sources are co mbined to determine meal size and postprandial satiety. (C) 1997 Elsev ier Science Inc.