Rate of inpatient weight restoration predicts outcome in anorexia nervosa.

Objective: To examine weight restoration parameters during inpatient treatment as predictors of outcome in anorexia nervosa (AN).

Method: Adolescent and adult females admitted for inpatient eating disorder treatment were recruited for an ongoing longitudinal study. This analysis examined several weight restoration parameters as predictors of clinical deterioration after discharge among participants with AN.

Results: Rate of weight gain was the only restoration parameter that predicted year 1 outcome. Clinical deterioration occurred significantly less often among participants who gained >or=0.8 kg/week (12/41, 29%) than those below this threshold (20/38, 53%) (chi(2) = 4.37, df = 1, p = .037) and remained significant after adjustment for potential confounders.

Discussion: Weight gain rate during inpatient treatment for AN was a significant predictor of short-term clinical outcome after discharge. It is unclear whether weight gain rate exerts a causal effect or is rather a marker for readiness to tolerate weight restoration and engage in the recovery process.