History of Overweight/Obesity as Predictor of Care Received at 1-year Follow-Up in Adolescents With Anorexia Nervosa or Atypical Anorexia Nervosa

Abstract

Purpose: Previous research has indicated that patients with anorexia nervosa (AN) or atypical AN with premorbid history of overweight/obesity have greater weight loss and longer illness duration than patients with no such history. However, little is known about the association of premorbid overweight/obesity and receiving inpatient medical care during treatment for an eating disorder.

Methods: Using logistic regression, we sought to determine if history of overweight/obesity was associated with receiving inpatient medical care in a sample of 522 patients (mean age 15.5 years, 88% female) with AN/atypical AN.

Results: Binary results demonstrated greater percent weight loss (27.4% vs. 16.2%) and higher percent median body mass index (%mBMI, 99.8% vs. 85.2%) at presentation in those with a history of overweight/obesity (p < .001) but no difference in duration of illness (p = .09). In models adjusted for demographics and percent weight loss, history of overweight/obesity was associated with lower odds of receiving inpatient medical care (odds ratio .60 [95% confidence interval: .45-.80]) at 1-year follow-up. However, these associations were no longer significant after adjusting for %mBMI. Mediation results suggest that %mBMI fully mediates the relationship between history of overweight/obesity and inpatient medical care, in that those with a history of overweight/obesity are less likely to receive care due to presenting at a higher weight.

Conclusions: Our findings suggest that, despite greater degree of weight loss and no difference in duration of illness, participants with a history of overweight/obesity are less likely to receive inpatient medical care.

Keywords: Adolescents; Anorexia nervosa; Atypical anorexia nervosa; Eating disorder; Inpatient medical care; Obesity; Overweight; Percent median body mass index; Percent weight loss.

Figure 1.

Mediation of association between history of overweight/obesity and inpatient medical care by %mBMI. ¹Step 1: Significant association between history of overweight/obesity (predictor) and inpatient medical care (outcome). ²Step 2: Significant association between history of overweight/obesity (predictor) and %mBMI (mediator). ³Step 3: Significant association between %mBMI (mediator) and inpatient medical care (outcome). ⁴Step 4: Association between history of overweight/obesity (predictor) and inpatient medical care (outcome) no longer significant after adjusting for mediating variable, %mBMI indicating full mediation. ⁵%mBMI = percent median body mass index. *p < .05, **p < .01, ***p < .001.