Compare and Contrast: Anorexia Nervosa, Bulimia Nervosa, and Binge Eating. (Onset, duration, Core Symptoms, Course) How do we differentiate one from the other? In which of the 3 disorders would you find: binge eating for 2-hour periods, self-perception as abnormal (perceive self as fat), compensate bingeing with exercise, BMI shows being underweight, feel a lack of control.