Eating Disorders

Eating disorders, which include anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED), are disorders defined by disturbances in eating behavior. Anorexia nervosa (AN) is the oldest recognized eating disorder. The salient features of this eating disorder are a relentless pursuit of thinness, accompanied by a fear of becoming fat despite being markedly underweight. In women, anorexia nervosa is associated with global endocrine dysregulation, including hypothalamic-pituitary axis dysfunction and alterations in adipokine and appetite regulating hormone levels. Bulimia nervosa (BN) is defined by eating behaviors that include episodes of binge eating which are followed by recurrent self-induced vomiting performed in an attempt to avoid weight gain from the caloric overload. Binge eating disorder (BED) is currently characterized by recurrent episodes of binge eating occurring at least twice a week for 6 months or longer. In contrast to bulimia nervosa, there are no inappropriate compensatory behaviors such as vomiting. Eating disorders frequently develop during adolescence or early adulthood, but some studies have reported their onset during childhood or later in adulthood. There is growing evidence supporting a multifactorial etiology that includes genetic, neurochemical, and physiological components for eating disorders above and beyond the more conventional theories based on psychological and sociocultural factors. Brain-derived neurotrophic factor (BDNF) plays a critical role in regulating nerves in the brain. Recent studies have provided evidence that BDNF also plays a role in regulating eating behaviors. In addition, an association between the BDNF gene polymorphism and eating disorders has been demonstrated. Other genetic risk factors for eating disorders have also been reported.