Eating and Appetite

Feeding can be defined as the behavioral response necessary for replenishing energy substrates to maintain energy balance and, ultimately, the survival of all organisms. Predictably, a shortage of food sources is associated with increased motivational states that promote food seeking, as well as metabolic changes that allow for energy stores to be amassed in the form of adipose tissue. In general, increases in these motivational states are commonly referred to as appetite (Berthoud and Morrison 2008). Feeding can also be elicited by the mere presence of food and, in the absence of a negative energy state, possibly as an adaptive behavioral response directed at storing excess energy in anticipation of future shortages. Clearly, the mechanisms regulating feeding behavior are complex and involve both regulatory and nonregulatory processes. Peripheral signals regulating energy balance. Both food intake and appetite are influenced by multiple neural and peripheral signals. These include energy substrates such as glucose, free fatty acids, and amino acids; hormones such as