The amount of food eaten is an essential component of the control of body weight. Food provides the chemical energy required for metabolism and for the storage of nutrients for later use. If the amount of ingested food is inadequate for the body’s needs, the animal will burn its endogenous stores of fat and protein and will lose weight. If food is eaten in excess of needs, some of that food will be stored in fat, muscle, and liver for later use. Thus, the proper control of food intake is essential for maintaining a healthy body composition and avoiding obesity.