An estimated 20 million US women (and 10 million US men) will have an eating disorder at some point in their lives, says the National Eating Disorders Association (NEDA). While the exact cause of eating disorders is unknown, they are believed to develop out of a combination of biological, psychological, and sociocultural factors. Every eating disorder has its own set of symptoms and side effects. Here, clinicians provide a rundown of recognized eating disorders that you should know about. Anorexia nervosa An anorexia nervosa diagnosis involves three main components. One, a person has limited eating so much that they have a significantly low body weight for their age and height. Two, even though they are underweight, a person is really scared of gaining weight or becoming overweight. (Andrea Vazzana, PhD, a clinical psychologist at NYU Langone Health's Department of Psychiatry, tells