Centro Interdisciplinar para o Estudo da Performance Humana (CIPER), Faculdade de Motricidade Humana, Universidade de Lisboa, Cruz Quebrada, Portugal.
Applied Psychology Research Center Capabilities & Inclusion (APPsyCI), ISPA - Instituto Universitário, Lisboa, Portugal.
Eat Weight Disord. 2021 Dec;26(8):2737-2748. doi: 10.1007/s40519-021-01148-x. Epub 2021 Mar 1.
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).
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.
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 χ(58) = 599.982; p < .001; χ/df = 10.345; CFI = 0.940; GFI = 0.941; SRMR = 0.063; RMSEA = 0.079 (LL = 0.073; UL = .084). Good internal consistency was achieved in all subscales (α > .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.
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 V, cross-sectional descriptive.
长期的体重管理需要持续参与与能量平衡相关的行为。根据自我决定理论，行为目标可以根据其内容的质量（即外在动机和内在动机）来支持或破坏动机。本研究旨在开发和验证体重维持量表的目标内容（GCWMS）。
GCWMS 被用于 1511 名参与者，他们已经取得了临床显著的体重减轻，并参加了一项大型体重维持研究：NoHoW 试验（ISRCTN88405328）。该量表源自两个关于运动目标的成熟问卷。对 4 个理论驱动领域进行了结构有效性检验：健康管理、挑战、形象和社会认可。采用分割样本验证性因子分析检验因子有效性和多组测量不变性（结构不变性、度量不变性、标度不变性和残差不变性）。还评估了可靠性估计值，并使用 2 个概念上相关的问卷评估了判别有效性。
第一次分析显示原始因子结构的拟合度较差。在删除 3 个项目后，对新指定模型的进一步研究表明，数据拟合度较好（χ（58）=599.982；p<.001；χ/df=10.345；CFI=0.940；GFI=0.941；SRMR=0.063；RMSEA=0.079（LL=0.073；UL=0.084）。所有分量表的内部一致性均较高（α>.775），通过与其他理论相关结构的关联验证了收敛和发散有效性。多组不变性检验的结果表明，GCWMS 的指定模型在性别上实现了完全测量不变性，但不支持跨国家的残差不变性。
研究结果支持 GCWMS 的假设的四维度结构，确认了因子结构的可靠性和多组不变性。分析还支持在性别和跨文化层面上对潜在因素进行有效的组间均值比较。讨论了改进量表质量的方法。
五级，横断面描述性。
