Meal size: role of reflexly induced insulin release

The amount of a particular food consumed during a meal is dependent on its sensory properties; moreover more food is consumed during a several course meal than during a single course one. The underlying physiological mechanisms are still unclear, but based on recent data, several hypotheses could be suggested. The determining effect of the sensory qualities of food on amount eaten could be dependent only on a direct action of incoming sensory information on the brain control systems. Reflex insulin secretions are triggered by sensory contact with food or food cues; the so-induced insulin secretions might play a crucial role in meal size determination. Finally, brain opiates possibly involved in the brain reward system might stimulate oral intake to a larger or lesser degree according to the hedonic hedonic properties of the presented food. Experimental arguments supporting these suggestions are presented.