There are many types of eating disorders, but this webpage describes the most common: anorexia, bulimia, and binge.

Anorexia Nervosa: due to an immense fear of being or appearing to be overweight, the people who experience this will try to maintain an unhealthy weight which can be life threatening.
Link to National Association of Anorexia Nervosa

Bulimia: due to the regrets of eating, the person who feels this way will most like cause self induced vomiting, which can be dangerous to his/her health.
Link to National Eating Disorders

Binge: due to not being able to stop eating, people will consume large amounts of food at unhealthy levels.
Link to Mayo Clinic