Using data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI), the researchers looked at the satiety hormone, Cholecystokinin (CCK), in 287 subjects. CCK is found in both the small intestines and the brain. In the small intestines, CCK allows for the absorption of fats and proteins. In the brain, CCK is located in the hippocampus, which is the memory-forming region of the brain.