Factors associated with weight gain in anorexia nervosa inpatients

Nutrition restoration in inpatients with anorexia nervosa (AN) is a core element in treatment, enabling recovery of cognitive functions essential for psychological care. This study aims to identify factors associated with inpatient weight gain.

Medical records from 107 inpatients aged 13-55 years with AN, hospitalized for more than 7 days at a specialized unit, were examined in a retrospective study. Weight evolution graphs were created for each patient and graded independently as optimal, moderate, and inadequate weight gain after 2 weeks and increasing, flat or decreasing weight in the first 2 weeks by expert clinicians. Driven by explicit hypotheses, bivariable analyses were carried out to detect relevant factors associated with weight gain during and after the first 2 weeks of admission.

Initial weight gain in the first 2 weeks of hospitalization and the introduction of a protocol harmonizing treatment procedures around rapid refeeding were strong factors associated with optimal weight gain after 2 weeks of hospitalization, whereas prior hospitalization in a psychiatric unit, diagnosis with binge-eating/purging subtype and age over 18 years were significantly associated with inadequate weight gain (p < 0.001-0.05).

To promote weight gain during hospitalization, clinicians should consider the following therapeutic measures: rapid refeeding strategies, renutrition protocols, and controlling purging behaviors.

Level III, retrospective cohort study.