Breast milk intake from 1 to 8.5 months of lactation in the multisite Mothers, Infants and Lactation Quality (MILQ) Study

Authors: MOORE, SOPHIE - King'S College; DEVI, SARITA - St John'S National Academy Of Health Sciences; KURPAD, ANURA - St John'S National Academy Of Health Sciences; PEERSON, JANET - Consultant; CHRISTENSEN, SOPHIE HILARIO - University Of Copenhagen; ISLAM, M. MUNIRUL - Icddr,b; KAC, GILBERTO - Universidade Federal Do Rio De Janeiro; MICHAELSEN, KIM - University Of Copenhagen; TORRES SILVA, GABRIELA - Universidade Federal Do Rio De Janeiro; Allen, Lindsay

Submitted to: Advances in Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2025
Publication Date: 8/26/2025
Citation: Moore, S.E., Devi, S., Kurpad, A., Peerson, J.M., Christensen, S., Islam, M., Kac, G., Michaelsen, K.F., Torres Silva, G., Allen, L.H. 2025. Breast milk intake from 1 to 8.5 months of lactation in the multisite Mothers, Infants and Lactation Quality (MILQ) Study. Advances in Nutrition. https://doi.org/10.1016/j.advnut.2025.100456.
DOI: https://doi.org/10.1016/j.advnut.2025.100456

Interpretive Summary: Exclusive breastfeeding is the optimal nutrition for infants and is recommended for the first six months. However, when the mother's diet is nutritionally inadequate the quality of human milk may be compromised. We investigated the relationships between maternal diet, human milk nutrient concentrations, and the volume of milk consumed in the Mothers, Infants and Lactation Quality (MILQ) study. Milk samples were collected throughout the first 8.5 months of lactation, in 558 well-nourished but unsupplemented women in Bangladesh, Brazil, Denmark, and The Gambia. Milk intakes were measured at three visits postnatally (1-3.49 months, 3.5-5.99 months, and 6.0-8.5 months). In three sites, milk volume was measured by giving the mother deuterium oxide but in Denmark, intakes were measured by weighing the infant before and after each feed for 24 hours. The average milk intake across sites and time points was 781 ±193 g/d. Milk intakes were similar between countries early in lactation but intakes decreased later in lactation at different rates due to the variable introduction of non-milk feeds. Exclusively breast-fed infants consumed more milk compared to mixed-fed infants. For the first time, we showed that the concentration of nutrients in milk was not affected by the volume of milk produced by the mother so infants who consumed more milk also consumed more nutrients . Average milk intake in the MILQ study was consistent with previously published global data. The implications for infant status and recommended nutrient intakes require further investigation.

Technical Abstract: Human milk from healthy, well-nourished women is the optimal nutrition for infants and young children, and exclusive breastfeeding is recommended for the first six months. In the context of poor diets, the nutrient concentrations in human milk may be compromised. In order to understand the relationship between milk nutrient concentrations and milk volume, this second article from the The Mothers, Infants and Lactation Quality (MILQ) study describes the volumes of milk produced through the first 8.5 months of lactation, in 558 well-nourished but unsupplemented women in Bangladesh, Brazil, Denmark, and The Gambia. Milk intakes were measured at three visits postnatally (1-3.49 mo, 3.5-5.99 mo, and 6.0-8.5 mo). In three sites, milk intakes were assessed using the stable isotope deuterium oxide ‘dose-to-mother’ method. In Denmark, intakes were measured by test weighing, and volume data were corrected by a factor of 1.05 to account for insensible water losses. The mean ± SD human milk intake across sites and time points was 781 ±193 g/d. Milk intakes were largely similar between countries early in lactation but between-site differences emerged as non-milk feeds were introduced. Exclusively breast-fed infants consumed greater volumes of milk across each day compared to mixed-fed infants, and when expressed against infant body weight, a gradual decrease in milk intakes was observed during lactation. Milk nutrient concentrations were largely unrelated to daily milk intakes. Therefore, correlations between the volume of milk consumed and the total daily intake of nutrients by infants were mostly positive and strong. Average milk intake in the MILQ study was consistent with previously published global data, although variability was observed both across lactation and between contexts. Infants consuming greater milk volumes had greater daily intakes of milk nutrients. The implications for infant status and recommended nutrient intakes require further investigation.