In lower-middle-income settings, growth faltering in the first 6 months of life occurs despite exclusive breastfeeding. The aim was to test the efficacy of an approach to improve the dietary adequacy of mothers during lactation and thus improve the growth of their infants. Eligible mother-infant dyads (infants less or 7 d of age) were randomly assigned to either intervention or control groups. Mothers in the intervention group received snacks that were to be consumed daily, which provided 600 kcal of energy – with 25-30% of energy derived from fats (150-180kcal) and 13% of energy from protein (80kcal). Micronutrients were supplemented as daily tablets. We provided counseling on breastfeeding and infant-care practices to mothers in both groups. The primary outcome was attained infant length-for-age z scores (LAZ) at 6 months of age. Secondary outcomes included exclusive breastfeeding proportion reported by the mother, maternal BMI and midupper arm circumference (MUAC), hemoglobin concentrations in mothers and infants, and the proportion of anemic infants at 6 months of age. We enrolled 816 mother-infant dyads. The intervention did not achieve a significant effect on LAZ at 6 months (adjusted mean difference: 0.09; 95% CI: -0.03, 0.20). Exclusive breastfeeding at 5 months was higher (45.1%vs. 34.5%; RR: 1.31; 95% CI: 1.04, 1.64) in the intervention group compared with the controls. There were no significant effects on mean hemoglobin concentration. We noted significant effects on maternal nutritional status (BMI, MUAC, hemoglobin concentration, and proportion anemic). Postnatal supplementation of 600 kcal energy, 20g protein, and multiple micronutrients daily to lactating mothers did not affect infant LAZ at 6 months of age. Such supplementation may improve maternal nutritional status.
