Fat and Obesity from a Neurophysiological Perspective

Abstract

Fat is the most energy dense macronutrient and attractive for animals. They have special brain system which actively consumes fat. This system consists of the hypothalamus, the limbic system and the basal ganglia. The hypothalamus acts as center of general feeding regulation and maintain homeostatic energy balance of organism. The hypothalamic feeding regulation highly depends on the energy balance and less leads to excessive energy intake. On the other hand, the limbic system and the basal ganglia control feeding less dependently on the energy balance. Limbic system mainly promotes palatability-induced feeding which is mediated by endogenous opioids and cannabinoids. Basal ganglia system manages reinforcement learning of feeding behavior which may cause development of habit-based eating. High-fat diet is highly palatable and highly reinforcing, and therefore, is highly influenced by the limbic and basal ganglia systems-mediated feeding control. These energy balance free feeding may promote feeding high-fat diet and, therefore, cause increasing of obesity in our modern food abundant society.