Differential Diagnosis of Orthorexia Nervosa
At first glance, there seems to be little difference between orthorexia and anorexia. However, there are many differences; the biggest one being that an orthorexic is not consumed by thoughts of being "thin" and losing weight. Also, somebody with anorexia (or bulimia, for that matter) focuses on the quantity of food, whereas an orthorexic concentrates on the quality. Anorexia literally means “absence of appetite.”
Orthorexia is not as common as anorexia and bulimia nervosa. Anorexic and bulimic patients are aware of the quantity, whereas orthorexics are aware of the quality of food. It is usually young adults who are subject to these eating disorders.