Breast Milk Composition, Milk Intake, and Their Relationship to Infant Weight Gain

An infant’s growth pattern over the first year of life sets the trajectory for growth during childhood. Rapid weight gain in infancy is a risk factor for childhood obesity in both breastfed and formula-fed infants. However, due to variation among mother-infant pairs, it is unclear how milk macronutrient composition and infant milk intake, as well as other maternal factors, contribute to infant growth in the first year of life. Milk samples were collected and infant milk intake over a 24-hour period was measured at 6 weeks postpartum from healthy mother-infant pairs (N = 122) enrolled in the STRONG Kids 2 cohort at the University of Illinois at Urbana-Champaign. Infants weighed an average of 7.8 ± 1.0 pounds at birth, with 74.6% delivered vaginally and 24.6% by cesarean section. At the time of sample collection, 77.8% of infants were breastfeeding, 13.9% were fed both human milk and formula (combined-feeding) and 6.7% were formula-feeding. Mothers were 31 ± 4.4 years old and had a BMI of 28.4 ± 6.6 kg/m2 at 6 weeks postpartum. Milk protein, fat, carbohydrate, and dry matter are being analyzed and the amount of each macronutrient consumed by infants over 24 h will be calculated. Ongoing analysis will investigate the relationship between milk composition, milk intake, and infant weight over the first year of life.Dairy Research InstituteGerber FoundationOpe