Eating disorders are a range of food and weight related issues. The three most common eating disorders are anorexia nervosa, bulimia nervosa and binge-eating disorder.
Anorexia Nervosa is an incredibly dangerous eating disorder in which people deny themselves food due to concerns they are overweight, even when they are extremely underweight.
Bulimia Nervosa involves an individual eating large amounts of food very quickly, with little control, followed by an attempt to purge the excessive calories through forced vomiting, fasting and excessive exercise.
Binge Eating Disorder causes a person to lose control, eating a large amount of food, often very quickly, even when they are not hungry. Because people with Binge Eating Disorder do not purge, exercise excessively, or otherwise go to extreme lengths to remove the excess calories, it often leads to significant weight gain.