Breastfeeding and dietary habits in childhood and adolescence: the PASOS study

OBJECTIVES: To assess the association between breastfeeding (BF) duration and dietary habits among children and adolescents. DESIGN: Cross-sectional analyses were conducted using data from two waves of the PASOS study (2019 and 2022), both multicenter observational studies nationally representative. METHODS: A total of 3588 participants from PASOS-2019-2020 and 2809 from PASOS-2022-2023, aged 8-16 years, with sociodemographic, BF, and dietary data were included. BF history was reported by caregivers and categorized into three groups: no BF, BF≤6 months, and BF>6 months. Dietary habits were assessed through a Mediterranean diet (MD) adherence validated index: the KIDMED. Associations between BF duration and KIDMED items were assessed using ANOVA, Chi-squared tests, and logistic regression models. RESULTS: Longer BF duration was associated with higher adherence to MD in both surveys. In 2019-2020, mean (SD) KIDMED scores were: no BF 6.5 (2.4), BF≤6 months 6.7 (2.4), and BF >6 months 7.0 (2.4), (p<0.001); in 2022-2023, corresponding values were 6.2 (2.4), 6.4 (2.5), and 6.7 (2.4), (p<0.001). Logistic regression analyses showed that in both 2019-2020 and 2022-2023, BF>6 months was associated with lower odds of skipping breakfast and higher odds of consuming cereals at breakfast, vegetables, and rice or pasta. Several associations remained significant after adjustment for exclusive BF and parents' education, employment status, and age, although effect sizes were attenuated. CONCLUSIONS: Longer BF duration was associated with healthier dietary habits and higher adherence to the MD in children and adolescents, but these associations may reflect broader early-life family and socio-educational contexts rather than a direct causal effect of BF itself. CLINICAL TRIAL REGISTRATION: The trial was officially recorded in 2019 with the International Standard Randomized Controlled Trial (ISRCT), bearing the identification number 34,251,612 accessed on 08/08/2019 https//www.isrctn.com/ISRCTN34251612 (21).