A system for stimulating the release of satiety hormone in a subject comprises a stimulus device which is implantable in the subject and adapted to apply an electrical stimulus to a tissue of a gastrointestinal system of said subject, and a detection device which is implantable in the subject and adapted to continuously monitoring at least one of a mechanical characteristic and an electrical characteristic of the subject to detect an ingestion of food by said subject, wherein the detection device cooperates with the stimulus device such that the stimulus device applies said electrical stimulus in response to a detected ingestion of food.