Interaction between breastfeeding duration and an obesity genetic risk score to predict body fat composition in European adolescents: The HELENA study Baxevanis, Georgios K. Gutiérrez Sáinz, Ángel HELENA study group Adolescents Breastfeeding Genetic risk score HELENA Study Interaction effect Health Institute Carlos III (ISCIII), Grant/Award Number: PI20/00988; European Community Sixth RTD Framework Programme, Grant/Award Number: FOODCT-2005-007034; the Iberus Talent Pre-doctoral fellowships 2018, under the European Union’s H2020 research and innovation programme under Marie Sklodowska-Curie, Grant/Award Number: 801586; the University of Zaragoza- Mecenazgo Santander Background Although the genetic interplay with the environment has a major impact on obesity development, little is known on whether breastfeeding could modulate the genetic predisposition to obesity. Objectives To investigate whether breastfeeding attenuates the effect of an obesity genetic risk score (GRS) on adiposity in European adolescents. Methods Totally 751 adolescents from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) cross-sectional study were included, divided according to breastfeeding status into never breastfed, 1–3 months and ≥4 months. Adjusting by socioeconomic status and lifestyle factors multiple linear regression models were used to assess (1) the main effect of breastfeeding duration and (2) its interaction effect with an obesity GRS, to predict different adiposity measures. Results A significant negative association between ≥4 months of breastfeeding and waist circumference (WC) z-score was observed [β (95% confidence interval), p-value] = [β = −0.189 (−0.37, −0.00), p = 0.044]. Also, significant interaction effects were observed for 1–3 and ≥4 months of breastfeeding and obesity GRS regarding body mass index (BMI) z-score [β = 0.155 (0.06, 0.24), p = 0.001] and [β = 0.108 (0.01, 0.18), p = 0.020, respectively] and fat mass index (FMI) z-score [β = 0.134 (0.04, 0.22), p = 0.003] and [β = 0.100 (0.01, 0.18), p = 0.026, respectively]. Conclusions Breastfeeding modulates the association between the obesity GRS and body composition in adolescents. 2025-03-03T10:09:11Z 2025-03-03T10:09:11Z 2025-01-21 journal article Baxevanis GK, Iglesia I, Seral-Cortes M, et al. Interaction between breastfeeding duration and an obesity genetic risk score to predict body fat composition in European adolescents: The HELENA study. Pediatric Obesity. 2025;e13205. doi:10.1111/ijpo.13205 https://hdl.handle.net/10481/102812 10.1111/ijpo.13205 eng info:eu-repo/grantAgreement/EC/H2020/801586 http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Wiley