How food preferences are learned: laboratory animal models.

Food selection represents a major challenge for omnivorous species. Faced with a variety of potential foodstuffs, many beneficial and some deleterious, the omnivore must decide which to eat and which to reject. The select-reject decision process involves an evaluation of the sensory characteristics of the foodstuff, particularly its flavour (i.e. taste, odour and texture). Innate predispositions such as a sweet-taste preference and bitter-taste aversion influence this process. With experience, animals refine their preferences as they associate the flavours of specific foods with the foods’ post-ingestive consequences. Social interactions also contribute to the food choices of many animal species. Until recently, most research has focused on conditioned food aversions which readily develop when animals experience gastrointestinal malaise after eating a new food (Braveman & Bronstein, 1985). It is now well documented that strong food preferences can also be learned as animals experience the positive nutritive effects of foods. As reviewed below, a variety of models have been developed using laboratory rats to reveal the intricacies of food-preference learning.