Dietary control and the stomach.

Signals for meal termination are traced to the stomach rather than duodenum or mouth when rats eat familiar food. Two types of signal occur, one measuring amount of nutrient independent of volume or dilution, the other gastric distention. The signals concerning the second ascend the vagus. Nutrient content is measured by some product of the digestive breakdown of the nutrient. The nutrient signals have to be calibrated through a process of learning. The gastric signals generated by food with a novel flavor are disregarded and oropharyngeal cues assume control instead. Finally, evidence against the role of cholecystokinin and bombesin in satiety is presented.