Development and cross-cultural validation of the Goal Content for Weight Maintenance Scale (GCWMS).

PURPOSE Long-term weight management requires sustained engagement with energy-balance-related behaviours. According to self-determination theory, behaviour goals can support or undermine motivation depending on the quality of their content (i.e., extrinsic and intrinsic motivation). This study aimed to develop and validate the goal content for weight loss maintenance scale (GCWMS). METHODS The GCWMS was administered to 1511 participants who had achieved clinically significant weight losses and were taking part in a large weight loss maintenance study: the NoHoW Trial (ISRCTN88405328). The scale derived from two well-established questionnaires regarding exercise goals. Construct validity was examined for 4 theory-driven domains: Health Management, Challenge, Image, and Social Recognition. Split-sample confirmatory factor analysis was conducted to test the factorial validity and multi-group measurement invariance (configural, metric, scalar, and residual invariance). The reliability estimates were also assessed, and discriminant validity was evaluated using 2 conceptually related questionnaires. RESULTS The first analysis showed a poor fit of the original factorial structure. Subsequent investigation with a new specified model indicated close fit to the data after removal of 3 items χ2(58) = 599.982; p   .775), convergent and divergent validity were verified through associations with other theoretical related constructs. Findings from multi-group invariance test demonstrated that the specified model of GCWMS achieved full measurement invariance for gender but did not support residual invariance across countries. CONCLUSION Findings support the hypothesised four-dimension structure of the GCWMS, confirming reliability and multi-group invariance in factor structure. Analysis also supports valid group means comparisons on latent factors at gender and at cross-cultural level. Ways to improve the quality of the scale are discussed. LEVEL OF EVIDENCE Level V, cross-sectional descriptive.