WHY DO WE EAT - A NEURAL SYSTEMS-APPROACH

Neuroregulators found at various brain sites are involved in controlli ng food intake, a behavior that occurs for many reasons. Different neu roregulators may affect different stimuli that impact eating behavior. For example, neuropeptide Y may initiate feeding for energy needs, op ioid peptides may provide the rewarding aspects of eating, and cortico tropin releasing factor may affect stress-induced eating. We know that the neural networks regulating feeding also impact other components o f energy balance. Neuropeptide Y not only increases eating, it also de creases energy expenditure in brown fat and increases enzymatic activi ty associated with fat storage in white fat, resulting in a more obese animal. What the sites of action are of these neuroregulators and how they interact with regulators at other sites are of utmost importance . Different regions of the brain, together with the periphery, communi cate via signals acting in coordinated fashion, which leads to the fin al outcome: eating less or more and expending less or more energy.