Neurobiological mechanisms of obesity

A high-fat and high-sugar diet affects both the homeostatic hunger and satiety signals in the hypothalamus and the hedonic reward system, leading to persistent hunger and a strong craving for high-calorie foods. Chronic stress potentiates the negative effects of a high-fat diet and promotes weight gain through certain neuronal processes. Current data suggest that the neuronal changes are difficult to reverse, which explains the much-cited yo-yo effect and the difficulties in long-term weight maintenance.