Relation between gastric emptying and short-term regulation of food intake in the pig

The relation between gastric emptying (GE), measured by gastric evacuation, and food intake (FI) was studied in pigs fed two meals to appetite per day. Duodenal infusion of emulsified fat (Intralipid; KabiVitrum) inhibited both FI and GE of digestible energy by more than the energy infused, but the gastric volume at satiety was more than 20% below the control. Duodenal infusions of glucose inhibited FI calorically, and generally inhibited GE calorically; but gastric volume at satiety was always equal to control volume. Thus GE (via gastric distension) may regulate FI to duodenal infusion of glucose but not to Intralipid. In pigs given no infusions, removal of the gastric contents immediately prior to the p.m. meal increased intake by 10%, However, when the contents were retained the pigs ate two equal-sized meals in the day, even though the gastric volume after the p.m. meal was 24% greater than after the a.m. meal. Therefore, although gastric volume may influence intake it cannot be the only factor determining satiety on this diet.