Common Characteristics of Anorexia Nervosa, Bulimia Nervosa, and Binge Eating Disorder

Anorexia nervosa and bulimia nervosa are characterized by severe disturbances of eating behavior. The salient feature of anorexia nervosa is a voluntary restriction of food intake relative to caloric requirements leading to an inappropriately low body weight. Bulimia nervosa is characterized by recurrent episodes of binge eating followed by abnormal compensatory behaviors, such as self-induced vomiting. AN and BN are distinct clinical syndromes but share common features. Both disorders occur primarily among previously healthy young women who become overly concerned with body shape and weight.

Anorexia Nervosa Bulimia Nervosa Binge Eating Disorder Clinical characteristics  Onset Mid-adolescence Late adolescence/early adulthood Late adolescence/early adulthood Female:male 10:1 10:1 2:1 Lifetime prevalence 1% of women 1–3% of women 4% of men and women Weight Markedly decreased Usually normal Usually obese Menstruation Absent Usually normal Usually normal Binge eating 25–50% Required for diagnosis Required for diagnosis Mortality 5% per decade Low Low Physical and laboratory findingsa  Skin/extremities Lanugo Callus/abrasion on dorsum of hand Acrocyanosis Edema Cardiovascular Bradycardia Hypotension Gastrointestinal Salivary gland enlargement Salivary gland enlargement Slow gastric emptying Dental erosion Constipation Elevated liver enzymes Hematopoietic Normochromic, normocytic anemia Leukopenia Fluid/Electrolyte Increased BUN, creatinine Hypokalemia Hypokalemia Hypochloremia Hypophosphatemia, Alkalosis Hypomagnesemia Endocrine Hypoglycemia Low estrogen or testosterone Low LH and FSH Low-normal thyroxine Normal TSH Increased cortisol Bone Osteopenia