This review discusses the role of enteroendocrine cells in the gastrointestinal tract as chemoreceptors that sense intraluminal contents and induce changes in food intake through the release of signalling substances, such as satiety hormones. Recent evidence supports the concept that chemosensing in the gut involves G protein-coupled receptors (GPCRs) that are known to mediate gustatory signals in the oral cavity. GPCRs can be grouped into several families, depending on the stimuli to which they respond, e.g. proteins, amino acids, carbohydrates, fatty acids, or tastants. Sensing of these stimuli by GPCRs results in hormone secretions of enteroendocrine cells, which participate in the control of food intake. A better understanding of the stimuli that induce the strongest binding with these receptors, and thus induce a strong release of hormones, can be a very useful strategy for the development of novel foods in the treatment of obesity.