Weight stigma in patients with overweight and obesity: validation of the Italian Weight Self-Stigma Questionnaire (WSSQ)

Purpose: This study aimed to explore the factorial structure of the Italian Weight Self-Stigma Questionnaire (WSSQ) (Study1); and to test structural validity, internal consistency, test–retest reliability, and measurement invariance of the questionnaire across gender, Body Mass Index (BMI), age and occurrence of previous hospitalization for obesity (Study2). Methods: At admission into a hospital-based program for weight reduction and rehabilitation, 150 inpatients with overweight/obesity (68% females) completed the WSSQ (Study1). In Study2, in addition to the WSSQ, 446 inpatients (61.9% females) completed the Weight Bias Internalization Scale (WBIS), the Body Uneasiness Test (BUT), and the Center for Epidemiologic Studies Depression Scale (CES-D). A subsample of 40 patients also re-completed the WSSQ at discharge from the hospital. Results: The Italian WSSQ showed good overlap with the original factorial structure (Study1) and results were confirmed in Study2. Test–retest reliability and convergent validity showed adequate values. Measurement invariance revealed that WSSQ was perfectly invariant across both BMI and the occurrence of previous hospitalizations for obesity. In both studies, the internal consistency of the questionnaire was deemed acceptable. Conclusions: The Italian WSSQ is a valid, reliable, and invariant tool for the assessment of weight-related self-stigma among patients with overweight/obesity. Future studies should assess its longitudinal invariance as well as its responsiveness to weight reduction treatments. Level of evidence: V, descriptive study.