The effects of specific nutrients on the regulation of feeding behaviour in human subjects.

Regulation of short-term energy intake involves the balance of positive drives to eat arising from the sight, smell and palatability of food with negative feedback signals from learned associations, gastrointestinal and metabolic signals. The stomach and small intestine are major sites in the feedback inhibition of food intake and subsequent period of appetite suppression. The present paper reviews the evidence that not only does the nature of the regulatory signal suppressing food intake depend on the type and energy content of nutrient consumed, but also the specific chemical composition of the nutrients and the site at which they are delivered. It is evident that feedback inhibition of feeding can be modulated by the particular chemical structure of nutrients (e.g. specific sugar or triacylglycerol structures). These differences in response are likely to be a consequence of differences in physical properties of particular nutrients depending on their chemical structure, and may also result from different receptor affinities for specific dietary structures. Moreover, the site of administration of nutrients can also profoundly affect the size and nature of the subsequent feeding response, suggesting that feed-forward interactions occur between the taste of foods and gastrointestinal stimulation.