Eating disorders are defined as eating habits that are harmful to an individual's health and involve issues with food and weight. The three most common types are anorexia nervosa, bulimia nervosa, and binge eating disorder. Anorexia is characterized by self-starvation and weight loss, bulimia involves binge eating followed by purging, and binge eating disorder involves periods of uncontrolled eating. Eating disorders can have serious medical and psychological complications if left untreated. Friends and family can help by educating themselves, expressing concern privately, and recommending counseling and support resources.