Energy homeostasis is controlled by complex pathways, coordinated in the central nervous system with the aim to maintain energy stores at appropriate levels for given environmental conditions. Over long intervals the amount of food consumed must provide energy equivalent to the amount of energy expend. Peripheral components such as adipose tissue, pancreas, gut, gustatory system and liver are in intimate bidirectional communication with the brain through either neural connections provided by autonomic nervous system, or hormones and metabolites. In the central nervous system signals are integrated in caudal brainstem, hypothalamus and parts of cortex and limbic system. Peripheral information on nutritional status of the organism and external information are integrated and translated in behavioral responses - choices and decisions, to eat or not to eat.