Abstract

Purpose: To identify patterns in the “Fat but Fit” paradox and its impact on cognitive performance and academic achievement in Chilean adolescents. This paradox suggests that better physical fitness may mitigate the negative effects of excess adiposity. Methods: A cross-sectional study, part of the Cogni-Action Project, included 1,296 adolescents (aged 10-14). Patterns of adiposity/physical fitness were identified using latent class analysis, and cognitive domains and academic grades were assessed. Results: Significant positive differences were found in global cognitive scores and academic performance between “thin-fit” adolescents and “unfit” adolescents (“thin-unfit” and “fat-unfit”, p = .023 and p = .007, respectively), and between “thin-fit” and “fat” adolescents (“fat-fit” and “fat-unfit”, p = .028 and p < .001, respectively). Conclusion: Higher physical fitness is associated with better cognitive performance, while lower adiposity is linked to greater academic achievement. The “Fat but Fit” paradox may influence these outcomes in different ways. © 2025 Human Kinetics, Inc.