ABSTRACT
Over the long-term food intake and energy expenditure must be in balance if body weight is to remain steady. Eating is a goal-directed behavior controlled in the shorter term by hunger signals, which motivate feeding, and satiety signals, which reduce it. An agent, neuron or pathway which stimulates appetite is said to be orexigenic, those which suppress appetite are anorexigenic. Food intake and energy expenditure are additionally regulated by hormones released from white fat cells (adipokines). The neural networks responsible for central regulation of feeding and energy expenditure lie in the hypothalamus and in the nucleus of the solitary tract, which lies in the medulla.
