Weight suppression at lowest weight as an indicator of eating disorder clinical severity: A retrospective cohort study.

Objectives: Weight suppression (WS) defines the difference between the highest weight in adulthood and the current weight. WS at lowest weight is the difference between the highest and the lowest ever weight. Weight rebound is the difference between the past lowest weight and current weight. The distinction in the capacities of WS, weight rebound, and WS at the lowest weight remains unclear regarding their efficacy in forecasting clinical endpoints. This study assessed the relationship between WS, WS at lowest weight and/or weight rebound and eating disorder (ED) clinical severity.

Methods: In this retrospective cohort study, adult participants were selected at the Outpatient Unit for multidisciplinary assessment of ED, Montpellier, France, between February 2012 and October 2014 and May 2017 and January 2020. ED clinical severity was evaluated using the Eating Disorder Examination Questionnaire (EDE-Q).

Results: The sample included 303 patients: 204 with anorexia nervosa (AN) and 99 with bulimia nervosa (BN). The EDE-Q total score was positively correlated with WS at lowest weight in patients with AN (Spearman's rho = 0.181, p = 0.015) and with BN (Spearman's rho = 0.377; p < 0.001). It was also positively correlated with weight rebound (Spearman's rho = 0.319; p = 0.003) in patients with BN. In the multivariate analysis, EDE-Q total score was associated with WS at lowest weight only in patients with BN (β = 0.265; p = 0.03).

Conclusion: WS at lowest weight seems to be a good measure of ED clinical severity. More research is needed for better understanding WS at lowest weight in assessment and treatment of patients with ED.