Higher body mass index (BMI) and internalizing symptoms often codevelop with each other, and both of them have been widely linked to child later maladjustment. However, existing studies on the association between BMI and internalizing symptoms predominantly focus on the between-person association (i.e., the average association for a given group) and use continuous measures of BMI. To address these gaps, using approaches that can effectively partition within-person from between-person variation, this study aimed to delineate temporal dynamics (i.e., directionality) of the associations between BMI and internalizing symptoms (as continuous and clinical cut-off categorical measures for both of them). The trend of codevelopment between BMI and internalizing symptoms is also investigated.

中文翻译：

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从儿童早期到青春期早期的体重指数和内化症状：共同发展和方向性的趋势

较高的体重指数 (BMI) 和内化症状通常相互共同发展，并且两者都与儿童后来的适应不良广泛相关。然而，现有关于 BMI 与内化症状之间关联的研究主要集中在人与人之间的关联（即给定组的平均关联）并使用 BMI 的连续测量。为了解决这些差距，本研究使用能够有效区分人内变异和人际变异的方法，旨在描绘 BMI 与内化症状（作为连续和临床截止分类测量）之间关联的时间动态（即方向性）对于他们两个）。还研究了BMI与内化症状之间的共同发展趋势。