Peer-reviewed article

Exclusive Breastfeeding and Growth Trajectories Until 5 Years of Age Among Children Monitored in Primary Health Care in Brazil.

Salviano AF, Guedes BM, Barros LM, de Oliveira NT, Farias DR et al. · 1 Jul 2026

Abstract

Objectives Exclusive breastfeeding (EBF) is relevant for child growth, especially in contexts of socioeconomic vulnerability. This study estimates growth trajectories until 5 years of age according to EBF among children monitored in primary health care in Brazil. Methods Longitudinal analysis using data from the Food and Nutrition Surveillance System (2015-2019). EBF was characterized according to food intake markers in two age groups (0 to < 3 and 3 to < 6 months). Mixed linear models with restricted cubic splines estimated trajectories of BMI-for-age (BAZ; n = 148 705 at 0 to < 3 months, n = 135 662 at 3 to < 6 months) and height-for-age (HAZ; n = 127 812 at 0 to < 3 months, n = 108 846 at 3 to < 6 months) z-scores using repeated anthropometric measurements collected after the exposure assessment. Results BAZ and HAZ were significantly higher until 6 months among exclusively breastfed children. Between ages 9-36 months, EBF interruption at 0 to < 3 months was associated with higher BAZ (reaching 0.70 z, 95% CI 0.69; 0.72 at age 18 months, vs. EBF: 0.59 z, 95% CI 0.58; 0.60). Higher HAZ was observed after age 9 months among children who were not exclusively breastfed. EBF interruption at 0 to < 3 months was related to higher BAZ at age 60 months (0.62 z, 95% CI 0.49; 0.74) compared to interruption at 3 to < 6 months (0.36 z, 95% CI 0.29; 0.44). Conclusions EBF was associated with higher BAZ and HAZ until age 6 months. Early EBF interruption led particularly to higher BAZ trajectories until age 5 years. Promoting adequate infant feeding practices may improve child growth.