Work

Breast Milk Macronutrients and Child Growth and Neurodevelopment in a Lactation Cohort in Rural Bangladesh

Year: 2026

Type: article

Abstract: Background Limited data exist on the relationship between breast milk macronutrient/energy concentrations and child outcomes in settings with high maternal undernutrition. Objective To determine associations of breast milk macronutrient (protein, fat, carbohydrate) and energy concentrations with child growth and neurodevelopment. Methods In this observational lactation cohort of 99 mother-infant dyads from Sylhet, Bangladesh, mothers provided hand-expressed breast milk samples at 2 and 5 months postpartum. Infant anthropometrics were obtained at birth, 3, 6, 12, and 24 months; neurodevelopment was assessed at 24 months using Bayley Scales of Infant and Toddler Development-III. Macronutrient concentrations were measured using mid-infrared spectroscopy. Associations with growth and neurodevelopment z-scores were estimated using mixed models and linear regression, adjusted for a priori confounders. Primary outcomes were length-for-age z-score (12-months) and cognitive z-scores (24-months) in relation to 2-month protein concentration. Results Breast milk samples were provided at 2 (n=98) and 5 months (n=87). We found no significant associations between 2-month protein and 12-month length-for-age z-scores or 24-month cognitive z-scores. Higher 2-month fat (g/dL) was associated with lower weight-for-age z-scores at 3 months ( b : -0.12 [95% CI -0.24, -0.005]) and lower head circumference-for-age z-scores at 3 (-0.20 [–0.32, -0.09]), 6 (-0.19 [-0.31, -0.08]), and 12 months (-0.17 [-0.29, -0.06]). Similarly, 2-month energy (kcal/dL) was inversely associated with 3-month weight-for-age z-scores (-0.01 [-0.03, -0.001]) and head circumference-for-age z-scores at 3 (-0.02 [-0.04, -0.01]), 6 (-0.02 [-0.03, -0.01]), and 12 months (-0.02 [-0.03, -0.01]). Higher 2-month carbohydrate (g/dL) was associated with higher motor z-scores (1.08 [0.06, 2.09]), and higher 5-month carbohydrate with higher cognitive z-scores (1.10 [0.15, 2.05]). Conclusions Protein concentrations were not associated with linear or cognitive outcomes in this cohort. Our findings suggest future studies targeting infant outcomes may optimally be designed to account for factors beyond macronutrient concentration, such as daily milk volume intake, that may impact infant growth and development. Teaser Text Higher early fat and energy concentrations in breast milk of Bangladeshi mothers was associated with lower infant head circumference and higher carbohydrate with higher neurodevelopment scores.

Source: Current Developments in Nutrition

DOI: 10.1016/j.cdnut.2026.109531