Data Sheet 1_Self-consciousness negatively mediates the positive association between internalized weight bias and weight status in cross-cultural survey and brain imaging study.docx

IntroductionWeight bias internalization (WBI), where individuals adopt negative stereotypes about excess weight, is linked to adverse health outcomes. Although prior research indicates associations between WBI, weight status, and psychological factors linked to self-consciousness, these relationships remain unclear. Thus, this study examined these associations and the relationship between brain characteristics and WBI or self-consciousness.
MethodsAn online survey was conducted in Japan (n = 1946), South Korea (n = 500), Germany (n = 598), and the United States (n = 580) to assess WBI, self-consciousness, and body mass index (BMI). In Japanese samples, associations between brain structural (n = 120) or functional (n = 30) characteristics and WBI or self-consciousness were explored.
ResultsSelf-consciousness negatively mediated the influence of WBI on BMI, varying across countries. Gray matter volume in the precuneus correlated positively with self-consciousness, while the subgenual anterior cingulate cortex (sACC) response to food reward correlated positively with WBI. Functional connectivity between the precuneus and sACC was positively associated with self-consciousness.
ConclusionSelf-consciousness may reduce the impact of WBI on BMI, and the precuneus could be related to this self-consciousness effect, providing further insight into the interactions between WBI and self-consciousness.

引言
体重偏见内化（Weight bias internalization, WBI）指个体接纳针对超重的负面刻板印象，该现象与不良健康结局密切相关。既往研究表明，体重偏见内化、体重状态以及与自我意识相关的心理因素之间存在关联，但上述关联的具体机制仍未明确。因此，本研究旨在探究上述关联，以及大脑特征与体重偏见内化或自我意识之间的关系。

方法
本研究在日本（n=1946）、韩国（n=500）、德国（n=598）及美国（n=580）开展在线调查，以评估体重偏见内化、自我意识以及身体质量指数（Body Mass Index, BMI）。在日本亚组中，本研究进一步探讨了大脑结构（n=120）或功能（n=30）特征与体重偏见内化或自我意识之间的关联。

结果
自我意识对体重偏见内化影响身体质量指数的过程起负向中介作用，且该效应存在国家间差异。楔前叶的灰质体积与自我意识呈正相关，而膝下前扣带回皮层（subgenual anterior cingulate cortex, sACC）对食物奖赏的响应与体重偏见内化呈正相关。楔前叶与膝下前扣带回皮层之间的功能连接与自我意识呈正相关。

结论
自我意识或可削弱体重偏见内化对身体质量指数的影响，而楔前叶可能与该自我意识效应相关，这为进一步阐明体重偏见内化与自我意识之间的交互作用提供了新的视角。