Clinician Practices in Determining Expected Body Weights Across Eating Disorders: A Mixed Methods Study

Eating disorder (ED) treatment often involves establishing expected body weights (EBWs). While individualised approaches are commonly used, whether and how EBWs are set across EDs, clinician perspectives on different approaches, and clinician training in this practice remain poorly understood. This study addressed these gaps, examining how clinicians navigate determination of EBWs.

A convergent mixed methods design was employed. Semi-structured qualitative interviews were conducted with 24 multidisciplinary ED clinicians to explore their experiences determining EBWs. Interviews were analysed using reflexive thematic analysis with a critical realist lens. Quantitative data, collected from 161 multidisciplinary ED clinicians via an anonymous online survey, captured the frequency of different approaches across ED diagnoses and age groups, common challenges, and training experiences.

Qualitative and quantitative data underscored clinicians' use of individualised approaches, frequent involvement of nutritional and medical professionals, and the challenge of limited access to patient's premorbid data. While interview participants described determining EBWs for all patients, quantitative descriptive data highlighted that EBWs were primarily determined for youth with anorexia nervosa and atypical anorexia nervosa.

Findings suggest that EBW determination practices vary, in terms of how and for whom EBWs are determined. Evidence-based guidelines are needed to support consistent EBW determination.