Satiety

Satiety refers to the state of being full or completely gratified after eating. This can happen to or beyond the point of "satisfaction", a state which, by contrast, is up to the eater to decide. For example, a person can feel full eating popcorn, but enjoy the taste so much, they keep eating until "satisfied".

Importantly, the calorie content of a food does not wholly determine satiety. A person can feel full after a moderate serving of a bland, watery, starchy food such as boiled potato­ but still feel peckish after devouring several times the calories in the form of croissants.

Over the years many foods have been studied for their effects on increasing satiety. Science is still investigating the complex signalling system between the brain and the stomach. What has been established is that the most important contributors to satiety are a hormone called cholecystokinin (CCK) and a protein called leptin, both of which signal to the brain that you are satisfied. These messengers respond differently to different foods. Generally, fats and proteins stimulate increased activity of these appetite controllers. But research has found that, compared to protein, far more calories from fat can be consumed, past the point of satiety, before one feels satisfied. Whey proteins have been found to provide greater satiety than other proteins.