The modified weight bias internalization scale: psychometric validation of three versions in a sample of university students.

Abstract

Purpose: The Modified Weight Bias Internalization Scale (WBIS-M) is perhaps the most frequently used measure of internalised weight bias and has growing support for its psychometric properties. However, there is a lack of clarity regarding how many items are necessary for adequate interpretation of the WBIS-M and limited study of internalised weight bias in young adults. The aims of this study are to evaluate different versions of the WBIS-M, assessing structural and convergent validity.

Methods: The current study recruited 205 university students (aged 18-46, mean body mass index = 22.60 kg/m²) in the UK and examined the factor structure, reliability, and convergent validity of the WBIS-M, looking at 11-item, 10-item, and 9-item versions.

Results: Confirmatory factor analysis suggested that a 10-item version of the WBIS-M showed acceptable structural validity and expected correlations with relevant constructs (depression, anxiety, weight status, and eating pathology). Estimates of internal consistency reliability were high for all three versions.

Conclusion: Given potential problems with one item, the 10-item WBIS-M presents a measure of internalised weight bias with sound psychometric properties in young adults.

Level of evidence: Level III, well-designed cohort study.