Eating disorders are severe psychiatric illnesses associated with high morbidity and mortality. The etiology of eating disorders is complex, with several biological, psychological, and social factors thought to contribute to their development and chronicity. Basic science and human brain imaging research have identified circuits that process food approach and avoidance and how food restriction or binge eating, in turn, alters those pathways. Human research in eating disorders across the diagnostic spectrum has indicated that reward and motivational salience circuits are altered and adapt to starvation and excessive food intake. This chapter integrates those findings and explains how fearful conditioning to food triggers striatal dopamine circuits to override appetitive signals and drives dread and avoidance rather than food approach. Shared elevated anxious traits but different neurobiological adaptive mechanisms perpetuate the vicious cycle of starvation in anorexia nervosa but intermittent excessive food intake in disorders associated with binge eating and higher body weight.