EFFECTS OF SOUP PRELOADS ON GASTRIC-EMPTYING AND FULLNESS RATINGS FOLLOWING AN EGG SANDWICH MEAL

To identify the source of inhibitory signals from the stomach or intes tine that lead to satiation, the effects of 300-g tomato soup preloads on the gastric emptying of a solid meal and on hunger and fullness ra tings were examined. Subjects were nine healthy women who each ingeste d an egg sandwich: 1) with no soup, 2) immediately after the soup, and 3) 20 min after the soup. Emptying of the sandwich was measured using radionuclide scintigraphy. Soup significantly prolonged the lag phase (period before significant emptying occurred, p < 0.05), and the half -emptying time (p < 0.01) of the sandwich, hut only when ingested imme diately before the sandwich. Thus, soup affected the emptying of the s andwich when the volume of soup in the stomach was at a maximum. Passa ge of soup into the duodenum over a 20-min period had no effect on emp tying of the sandwich. Despite the different gastric/postgastric distr ibutions of the soup and the sandwich in the two preload conditions, f ullness ratings were not different.