Why a palatability construct is needed.

Palatability is a hypothetical construct which is needed to account for the hedonic aspects of the taste, smell, flavour, texture, etc. of food. Palatability is influenced by innate factors, but can also be modified by learning. Powerful preferences and aversions can be conditioned by the aftereffects of food ingestion. Despite the common assertion that palatability is enhanced in a state of relative food deprivation, there is evidence to suggest that hunger and palatability act largely independently to determine intake. Accordingly a distinction should be made between the pleasantness of the taste of food (influenced by palatability) and the pleasantness of ingesting that food (influenced by hunger/satiety). Increased palatability appears to be at least part of the explanation of why certain diets promote hyperphagia and obesity. However, the postingestive effects which contribute to the greater palatability of such diets remain to be identified.