A study published this month in Archives of Pediatric and Adolescent Medicine looks at the relationship between infant feeding practices and weight gain (1). Breast milk vs. formula? Nope, it isn’t that simple.
Led by Dr. Ruowei Li of the CDC, this prospective longitudinal study tracked feeding and weight gain in 1900 infants during their first year of life. Each month, mothers were asked how they fed their babies in the last 7 days, and from their replies, infants were grouped into the following categories across ages:
- Breastfed only
- Breastfed and human milk by bottle
- Breastfed and formula by bottle
- Human milk by bottle only (i.e. exclusive pumping)
- Human milk and formula by bottle
- Formula by bottle only
The mothers in this study were mainly white, married, and had at least a high school education. A third were on WIC. About 50% were overweight or obese. Statistical methods were used to adjust the findings for a range of maternal factors, including BMI, as well as infant sex, gestational age, birth weight, and age of solid food introduction.
The most important finding from this study was that infants fed by bottle only – whether fed formula or breast milk – gained more weight than those fed breast milk at the breast. Continue reading