Bioecological correlates of learning outcomes: testing the moderating role of obesity in academic performance.

Introduction: This study examined the moderating role of obesity in adolescent academic performance using the Bioecological Model of Human Development as the theoretical framework. Methods: Data from 2,127 adolescent students in the PISA 2022 dataset were analyzed using multi-group path analysis. Results: Sixteen of the seventeen associations examined were of comparable magnitude in the two groups, and the joint test of all seventeen provided no evidence of moderation. Contrary to expectations, body image was negatively associated with achievement in both groups, meaning that adolescents more satisfied with their bodies performed less well. The association was more than twice as strong among obese adolescents, the only between-group difference observed, and it did not persist after adjustment for multiple comparisons. Psychosomatic symptoms also showed a positive relationship with achievement, contrary to what the literature reports, reaching significance among obese adolescents alone, while perceived school safety reached significance only among their non-obese peers; in neither case did the groups differ. Curiosity, emotional control, and perseverance were positively related to achievement in both groups, and social connections, cooperation, and school risk were negatively related. Discussion: These findings locate the difference associated with obesity in adolescents' body-related self-perception rather than in the relational or institutional resources available to them. Educational strategies that address weight-inclusive environments and bias training may therefore complement traditional health-focused interventions in supporting these students.