Rationale: The appearance of tastants in the small intestine can result in the activation of a negative feedback mechanism from different parts of the intestine to the stomach, the small intestine and to the central nervous system. These processes inhibit food processing, appetite sensations and food intake, and furthermore they increase feelings of satiety and satiation. The effects of intraduodenal and/or intraileal infusion of a combination of tastants (sweet (rebaudioside A), bitter (quinine) en umami (monosodium glutamate(MSG))) and placebo on ad libitum food intake, satiation and gastrointestinal symptoms will be investigated.