New developments in the assessment of weight-related experiential avoidance (AAQW-Revised)
Lara Palmeira, Marina Cunha, José Pinto-Gouveia, Sérgio Carvalho, & Jason Lillis
Experiential avoidance, defined as attempts to control or change unwanted internal experiences when doing so causes harm, has been consistently associated with physical and mental health problems and has been traditionally measured using the Acceptance and Action Questionnaire. Several studies have highlighted the importance of developing content-specific measures to better capture relevant processes for specific populations. One such measure is the Acceptance and Action Questionnaire for Weight-Related Difficulties (AAQ-W), which measures experiential avoidance of unwanted weight related thoughts, feelings and actions. The AAQW factor structure still requires further examination.
The present study aims to contribute to the further development of the AAQW by conducting a confirmatory factor analysis (CFA) based on the existent factor structures and testing the measurement invariance across groups, through a multi-group analysis. Three distinct samples were used: the CFA used 215 women from the general population with BMI<25 (sample 1); 210 overweight or obese treatment seeking (sample 2); AAQW's temporal stability and sensitivity to change was assessed using a sample of 58 overweight and obese women enrolled in Kg-Free (sample 3). Results supported a revised and shorter version of the AAQW (10 items) that we call AAQW-R (revised) with a three-factor structure (food as control, weight as barrier to living, weight-stigma) that showed a good fit to the data. Also, the measurement invariance across groups was confirmed. Finally, AAQW-R proved to be a reliable, stable measure and sensitive to clinical changes. Overall, this study offers new advances in the assessment of weight-related experiential avoidance, proposing a revised version of the AAQW. Moreover, it provides evidence for the usefulness of the AAQW-R both in general and clinical populations.