Eating disorders and obesity are multifactorial disease conditions with several accompanying comorbidities, including a shortened life span. Entangled among their risk factors and within their intricate pathogenesis is mental stress. This power of the mind has been repeatedly shown to affect somatic illnesses, most commonly coronary artery disease (Iso et al., 2002; Krantz, Shaps, Carrey, & Natelson, 2000; Sheps et al., 2002), so mental stress may convincingly result in physical harm. The center of appetite regulation is in close proximity to areas that control the stress response in the hypothalamus, hence the connection between feeding regulation and stress seems not to be by chance. It should be noted that the topic is broad, and the interrelationships within and between biological, psychological, and social factors are complex. This chapter will present several key issues regarding the role of stress in the pathogenesis and etiology of eating disorders, chiefly anorexia nervosa (AN), bulimia nervosa (BN), and obesity.