Katelyn Gordon, MD

Pre-Morbid Obesity as a Determinant of Physical and Psychological Morbidity in Adolescents with Restrictive Eating Disorders

Katelyn Gordon, MD; Abigail Matthews, PhD; Adi Ziv, MD; Jessica Kahn MD

Patients with both anorexia nervosa and atypical anorexia nervosa have significant associated physical and psychological morbidity, regardless of premorbid weight status.

-Katelyn Gordon, MD


Background: Eating disorders are a significant public health concern given their prevalence and associated morbidity and mortality. Patients may present with a variety of medical complications of disordered eating including bradycardia, orthostatic instability, and electrolyte derangements, in addition to psychiatric co-morbidities including anxiety and depression. Greater amount and velocity of weight loss increase the risk of medical complications experienced by patients with atypical anorexia nervosa (AAN) and anorexia nervosa (AN). Furthermore, patients with premorbid obesity have been found to have larger degree of weight loss prior to diagnosis and longer disease duration. 

Objective: Patients with obese and overweight status prior to diagnosis of AN/AAN are at higher risk of presenting with medical complications related to malnutrition and to present with premorbid psychiatric illness.

Methods: Data extraction was performed using retrospective chart review of patients with AN and AAN admitted between 2012-2020. Medical and psychiatric history, anthropometric data, orthostatic data, electrocardiographic data, and laboratory data were collected. Statistical analysis using ANOVA and Chi-Square tests were performed.

Results: 259 patients were included in our analysis with mean age 15.5, majority female (88%), and majority white (97%). 100 patients had diagnosis of AAN (39%) and 150 had diagnosis of AN (61%). Patients with premorbid obesity and overweight lost significantly more weight than those with premorbid normal weight (p<0.001). There was a statically significant difference between mean ALT (p=0.046) and AST (p=0.044) on presentation between those with pre-morbid obesity, overweight, and normal weight. No additional significant relationships were observed between pre-morbid weight status and orthostatic instability or other laboratory and electrocardiographic markers assessed. There were no statistically significant relationships between premorbid weight status and mental health history, psychiatric medication use, and suicide attempt. Patients with premorbid overweight and obesity required significantly higher levels of calories at discharge to achieve medical stability when compared to patients with premorbid normal weight (p=0.022). Patients with premorbid obesity and overweight were significantly more likely to be diagnosed with AAN over AN (p<0.001).

Conclusions: Taken together, while a greater degree of weight loss and caloric needs were observed in patients with premorbid obesity and overweight, there were few differences in medical and psychiatric morbidity between patients with AAN and AN of different premorbid weight statuses.