Resumen: Background: Overweight and obesity in children are rising globally, and the Mediterranean diet may help reduce obesity and related diseases. Objective: To assess the association between adherence to the Mediterranean diet and body composition in Spanish preschool children. Methods: This study included 1218 children aged 3–6 years from the CORALS cohort. Mediterranean diet adherence was evaluated using the validated MED4CHILD and COME-Kids F&B-FQ; questionnaires. Body composition measurements included weight, height, waist circumference, BMI, Fat Mass (FM), Fat-Free Mass Index (FFMI), and Waist-to-Height ratio (WtHR). Multivariate regression and ANCOVA were used to examine associations, adjusting for factors like age, physical activity, and energy intake. We also performed a Cohen's d analysis to assess effect size. Results: Adherence to the Mediterranean diet was associated with more favourable body composition in children. Specifically, both the MED4CHILD score and the COME-Kids-derived score showed significant associations with BMI, FFMI, and Waist-to-Height ratio, showing differences by sex. Children who adhered to the Mediterranean diet exhibited lower BMI and higher fat-free mass, and a more favourable waist-to-height ratio. Additionally, although some measures showed weaker associations, all analyses highlighted a trend towards improved body composition with higher adherence. Cohen's d analysis showed small to moderate effect sizes. Conclusion: Adherence to the Mediterranean diet was significantly linked to favorable body composition indices in Spanish children, highlighting the importance of promoting healthy dietary patterns to prevent overweight and obesity. Idioma: Inglés DOI: 10.1111/ijpo.70014 Año: 2025 Publicado en: Pediatric obesity 20, 7 (2025), e70014 [12 pp.] ISSN: 2047-6302 Tipo y forma: Artículo (PostPrint) Área (Departamento): Área Enfermería (Dpto. Fisiatría y Enfermería) Área (Departamento): Área Medic.Prevent.Salud Públ. (Dpto. Microb.Ped.Radio.Sal.Pú.)