In 1981, the Eating Disorders Unit at Massachusetts General Hospital (MGH) opened, with Dr. David Herzog as its founder and director. He went on to create the Harvard Eating Disorders Center, which later became the Harris Center for Education and Advocacy in Eating Disorders at MGH. Eating disorders are serious psychiatric illnesses that affect both the brain and the body. Individuals struggle with negative thoughts and feelings about the size and shape of their bodies and engage in unhealthy weight control behaviors (food restriction, binge eating, and purging). One of the main eating disorders is anorexia nervosa, which is widely known as the self-starvation disease. People with anorexia perceive themselves as overweight even when they are painfully thin, and many are reluctant to admit they have a problem or need help. Bulimia nervosa is characterized by repeated episodes of binge eating followed by unhealthy behaviors – self-induced vomiting or the misuse of laxatives or diuretics (pills that increase the excretion of water from the body)– aimed at preventing the calories ingested during the binge from resulting in weight gain. Many individuals with bulimia are normal in weight and look healthy; they are often ashamed of their abnormal eating behaviors and go to great lengths to keep them secret. Binge eating disorder is more common than either anorexia nervosa or bulimia nervosa. Unlike individuals with bulimia nervosa, those with binge eating disorder do not purge or engage in other behaviors (such as over-exercise or fasting) aimed at compensating for the calories eaten during a binge. Many people with binge eating disorder are overweight or obese and experience marked distress about their abnormal eating habits. There are no definitive answers to the question of what causes eating disorders. A number of factors – including genetic predisposition, neurobiology, personality characteristics, and environment – play a role. Research is currently under way to determine how these factors interact.