Behavioral controls of food intake.

Recent conceptualizations of food intake have divided ingestive behavior into multiple distinct phases. Here, we present a temporally and operationally defined classification of ingestive behaviors. Importantly, various physiological signals including hypothalamic peptides are thought to impact these distinct behavioral phases of ingestion differently. In this review, we summarize a number of behavioral assays designed to delineate the effects of hormone and peptide signals that influence food intake on these ingestive mechanisms. Finally, we discuss two issues that we have encountered in our laboratory which may obstruct the interpretation of results from these types of studies. First, the influence of previous experience with foods used in these behavioral tests and second, the importance of the nutrient composition of the selected test foods. The important conclusion discussed here is that the behavioral analysis of ingestion is accompanied by theoretical constructs and artificial divisions of biological realities and the appreciation of this fact can only increase the opportunities of contemporary behavioral scientists to make significant and novel observations of ingestive behaviors.