Infant Feeding Practices and Their Association with Early-Life Nutrient Intake: Baseline Findings from the Baby-Act Trial.

Introduction: This is a secondary cross-sectional analysis of participants' baseline data from the Baby-Act Trial to compare energy and macronutrients intake by feeding type. This was a cluster-randomized clinical trial among pregnant women and their infants participating in the Puerto Rico WIC program to test the clinical effectiveness of an intervention that addressed various infant obesity risk factors during the first year of life.

Methods: Participants completed at baseline a sociodemographic questionnaire and a validated infant food frequency questionnaire (FFQ). The FFQ was analyzed for type of feeding (exclusively fed breastmilk, fed breastmilk and formula, or exclusively fed infant formula) and for energy and macronutrient intake (protein, carbohydrate, and fat). Analysis of covariance was used to compare intake type of feeding, adjusting for maternal age. race, education, number of previous children, gestational length, and pre-pregnancy BMI.

Results: The present analysis included 368 mother-infant pairs. Mean age of mothers was 26.7 years and of infants 0.7 months. Ten infants fed complementary foods were removed from the analyses. A total of 39.9% of infants were exclusively breastmilk-fed, 47.2% were fed breastmilk and infant formula, and 12.8% were exclusively formula-fed (n = 358). Intake of energy, protein, fat, and carbohydrates was significantly lower in infants fed only breastmilk compared to infants fed a combination of breastmilk and infant formula, and intake of protein and carbohydrates were lower in infants fed a combination of breastmilk and infant formula compared to infants fed only infant formula, after adjusting for important confounders.

Conclusions: Very early infant feeding practices are associated with differences in dietary intake. The long-term health implications of this findings need to be further studied.