Assessing Satiety satiety, or fullness, occurs long before sufficient nutrients make their way into cells.Stomach fullness provides an early warning signal to tell us that we have eaten enough.In extreme cases of obesity, some people have a portion of their stomach stapled in hopes of feeling full faster and therefore eating less. The intestines also provide satiety signals. The duodenum, shown previously in Figure 9.14, join the stomach and the small intestines. When duodenal glucoreceptors sense sugars, eating generally stops quickly. The arrival of food, especially very fatty food, at the duodenum signals the release of the peptide cholecystokinin (CCK). CCK promotes the release of insulin by the pancreas and contracts the gallbladder to release bile to help break down fats. CCK clearly contributes to feeling of satiety (Stacher,1986),but the exact machanism for this effect is unclear. CCK also functions in the brain as neurotransmitter related to satiety. CCK antagonists increase eating, indicating that CCK has an inhibitory effect on feeding behavior Cooper & Dourish, 1990)