At its most severe, a weight obsession can turn into an eating disorder, which the National Institutes of Health define as "an illness that causes serious disturbances to your everyday diet, such as eating extremely small amounts of food or severely overeating ... Severe distress or concern about body weight or shape may also characterize an eating disorder."
There are three primary types of eating disorders:
Anorexia nervosa is characterized by an irrational fear of gaining weight, an extremely restricted caloric intake that leads to emaciation, a distorted body image and lack of menstruation in females.
Unlike anorexics, those who have bulimia nervosa will, in fact, eat large quantities of food. But these binging sessions are followed by a sense of guilt and subsequent extreme behaviors such as purging through the use of forced vomiting or laxatives and/or diuretics; excessive exercise; fasting; or any combination of these methods.
While most eating disorders result in unhealthily low body weights, with binge-eating disorder, the opposite may occur. That's because binge eaters lose control over the quantities they consume, but don't follow these sessions with purging, severe calorie restriction or excessive exercising. It's the most common of the eating disorders and because foods often associated with binge eating are high in fat and low in protein, complications like obesity, Type 2 diabetes, high blood cholesterol, high cholesterol, gall bladder disease and heart disease are often common.
Treatments for eating disorders include psychotherapy, nutrition education, antidepressants and anti-anxiety medications, and in the most severe cases, hospitalization may be necessary.