Weight suppression at lowest weight as a mediator between childhood maltreatment and eating disorder severity: a retrospective cohort study

Abstract Purpose The aim of the study was to assess the relationship between weight suppression at lowest weight (WS-LW) and eating disorder (ED) clinical severity, and to test WS-LW role as a mediator of childhood maltreatment (CM) impact on ED. Methods For this retrospective cohort study, adult participants were selected at the Daycare Unit for multidisciplinary assessment of ED in Montpellier, France, between March 2013 and January 2020. Mental health professionals assessed and recruited patients with ED (n = 321). For each patient, they collected sociodemographic characteristics, body weight and height, and the results of the Mini-International Neuropsychiatric Interview, and the self-report Eating Disorder Examination-Questionnaire (EDE-Q) and Child Trauma Questionnaire (CTQ). The collected data were assessed using descriptive bivariate, Receiver Operating Characteristics (ROC), and mediation analyses. Results Participants were mainly women (94.39%; median age: 25.67 years); 216 (67.29%) had anorexia nervosa and 105 (32.71%) bulimia nervosa. A positive correlation was found between WS-LW and EDE-Q total score (Spearman’s rho = 0.262; p < 0.001). The ROC analysis (AUC = 0.586 at 95% confidence interval; p = 0.016) identified a WS-LW cutoff of 14.99 (sensitivity = 64.6%; specificity = 51.5%) to differentiate between clinically severe and non-severe ED. WS-LW mediated the relationship between CM severity and ED clinical severity (β = 0.024; 95%CI = 0.001–0.054). Conclusion Patients with ED and history of CM have higher WS-LW, an easy-to-determine parameter and a marker of more severe eating psychopathology in ED. WS-LW is also a clinical mediator of the relationship between CM and ED.