Weight suppression as a predictor variable in the treatment of eating disorders: A systematic review

WHAT IS KNOWN ON THE SUBJECT?: Weight suppression (WS) has been suggested to predict outcome following psychological treatment for an eating disorder (ED). Some findings are contradictory and have not been considered systematically. WHAT THE PAPER ADDS TO EXISTING KNOWLEDGE?: The review suggests that weight gain at post-treatment is reliably predicted by pretreatment WS, but findings regarding other outcomes (e.g., treatment dropout) are less consistent. Approximate effect sizes for observed relationships are identified, alongside support for biobehavioural theories of metabolic adaptation to weight loss. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Degree of WS at pretreatment is associated with weight gain and is important for clinicians to consider before offering treatment to patients with EDs. Patients high in WS might benefit from further support (e.g., psychoeducation) prior to beginning treatment. ABSTRACT: Introduction Weight suppression (WS-the difference between highest body weight and current body weight) has been proposed as a predictor of treatment outcome within eating disorders (EDs), although this hypothesis has not been consistently supported. Aim/Question Review the association between pretreatment WS and outcome following psychological treatment for EDs. Method A comprehensive electronic database search for published and unpublished literature from 1979 to 2017. Reference lists were also inspected. Eligibility criteria were determined according to relevant guidelines and a quality appraisal was conducted. Results Twelve studies met inclusion criteria (one was subsequently excluded based on insufficient data). Greater WS was generally associated with weight gain at post-treatment although not with other treatment outcomes. Discussion The existing evidence, with data from 1,566 participants, is summarized according to three main post-treatment outcomes: weight change; treatment completion; and symptom abstinence. Patients with disordered eating and greater WS may need to gain more weight than others during treatment to achieve good outcomes. Recommendations for future studies are provided. Implications for practice Evidence-based treatments for EDs may benefit from considering WS when planning treatment, such as further psychoeducation on weight changes. Societal interventions regarding promotion of healthy eating may also draw on these findings.