Typical Volumes of Human Milk Intake Among Infants and Young Children
by Anne Eglash MD, IBCLC, FABM
What is the average amount of breastmilk needed by an infant?
Many new parents wonder how much breastmilk a typical baby drinks in 1 day, especially if they are planning to send their infant to daycare. According to the authors of this week’s research, several studies have been done world-wide on breastmilk volume intake, using different methods of measurement, but there has not been an updated systematic review on this topic since the World Health Organization’s research in 1998. This paper was commissioned by the Food and Agriculture Organization of the United Nations and the World Health Organization.
This systematic review and meta-analysis included 167 studies that measured breastmilk intake among 20,857 participants. The studies were well distributed internationally, with all continents represented. The majority of studies included healthy lactating individuals, while 61/167 studies didn’t specify health status. A few studies included lactating individuals with diabetes, thyroid disease, ovulatory disturbance, HIV, mastitis, nipple pain, and ankyloglossia. The methods used to determine milk intake included deuterium dilution and/or test weighing.
Deuterium oxide dilution is considered safe and involves giving the lactating parent a dose of deuterium-labeled water, which mixes in the body’s water pool. The amount of deuterium-labeled breastmilk consumed by the infant when directly feeding is then measured over time by monitoring the deuterium in the infant’s urine.
The meta-analysis and meta-regression of the data demonstrated that for healthy term exclusively breastfed infants, the average intake per body weight peaks at 1 month, at 135ml/kg/day. It gradually declines from there, with the average intake at 6 months being 107ml/kg/day, and 61ml/kg/day at 12 months. What else? See the question!
- Infants of mothers with a high BMI took more milk than those with a lower BMI.
- The intake of breastmilk peaks at 3-4 months, then plateaus until complementary foods are started.
- The volume of breastmilk intake is influenced by infant body weight.
- The global average peak breastmilk intake is 724-755ml/day, or 24-25 ounces/day.
See the Answer
The objective of this study was to provide global breast milk intake estimates for infants and children from 0 to 3 years old.
Materials and Methods
A systematic search of online databases (Embase, MEDLINE, and CENTRAL) was conducted and complemented with a manual search of additional databases (African Journals Online and LILACS), reference lists, and unpublished data. Studies with apparently healthy mothers and their children 0–3 years old worldwide were included. Random effects meta-analyses, subgroup analyses, and meta-regressions were conducted.
A total of 167 studies on breast milk intake were identified. The mean daily breast milk intake among all the studies included was 670 mL per day and 117 mL/kg per day. Breast milk intake was influenced by infant age, infant body weight, and breastfeeding practices. The deuterium dilution method tended to yield higher estimates than test-weighing methods. Breast milk intake over time was modeled with a nonlinear metaregression: breast milk intake (mL/day) = 51–1.4 · days +180 · log(days). When restricting to studies involving healthy term infants exclusively breastfed up to 6 months, breast milk intake was 624 mL per day and 135 mL/kg per day at 1 month, 735 mL per day and 126 mL/kg per day at 3 months, 729 mL per day and 107 mL/kg per day at 6 months, and 593 mL per day and 61 mL/kg per day at 12 months.
This review provides global breast milk intake estimates for infants and young children. It demonstrates differences in intakes according to region and measurement method, as well as longitudinal changes over the first year of life.
The researchers found that there was no association between maternal BMI and breastmilk intake.
This is a resourceful study, as it includes global data with detailed charts demonstrating typical breastmilk intake/day during 2 years of a child’s life. Their data is very similar to the results in the 1998 study.
One major limitation of this systematic review and meta-analysis is that 61/167 of the studies did not define the health status of the lactating mothers. Therefore, the data describes infant breastmilk intake in a variety of populations in their current state (a reference) but does not describe breastmilk volumes in optimal health and socioeconomic conditions (a true standard). An analogy would be comparing growth charts in populations where the health of the family and infant are not optimized (a reference), vs the WHO curves that measured growth trajectories in healthy populations living in optimal conditions (a true standard).