(P18-007-23) Associations of Feeding Type and Feeding Mode With Infant Appetitive Traits and Body Weight in the First 6 Months

Objectives: To: 1) determine associations of feeding type and mode at 6 weeks with infant appetitive traits and BMI z-scores (BMIZ); and 2) examine associations of infant appetitive traits with BMIZ at 6 months.

Methods: We studied 55 mother-infant dyads from the Mother & Infant Metabolome & Microbiome Study, a multi-center longitudinal cohort study of mothers intending to breastfeed healthy newborns. At 6 weeks, mothers completed infant feeding logs detailing type, mode, and volume of feedings over a representative 24-hour period. Using these data, infants were classified by feeding type (only breast milk vs. any formula) and mode (only breastfeeding vs. any bottle). At 6 months, mothers completed the validated Baby Eating Behavior Questionnaire to assess features of infant feeding behavior. At 6 weeks and 6 months, parent-reported infant anthropometrics, derived from clinical visits, were used to calculate BMIZ. T tests were used to determine differences in appetitive traits and BMIZ based on feeding type and mode. Adjusted linear regression was used to quantify associations of appetitive traits with BMIZ at 6 months.

Results: Mean ± SD maternal age was 35 ± 4.0 years and early pregnancy BMI was 26 ± 5.3 kg/m². Infants had an average gestational age of 39 ± 1.9 weeks, birthweight of 3439 ± 411 grams, and 45% were female. Seventy-five percent of infants were fed only breast milk (vs. any formula) and 36% were fed only at the breast (vs. any bottle). Infants who received only breast milk had higher food enjoyment scores versus those who received any formula (4.6 ± 0.3 vs. 4.3 ± 0.5, P = 0.03). Infants who were only breastfed trended toward higher satiety responsiveness scores than those who received any bottle feeding (2.5 ± 0.5 vs. 2.1 ± 0.8, P = 0.07). There were no differences in infant BMIZ by feeding type or mode at 6 weeks. There were no associations of appetitive traits with BMIZ at 6 months.

Conclusions: Our findings suggest that feeding type and mode influence diverse aspects of infant appetite, perhaps reflecting both innate feeding behaviors in infants as well as maternal perceptions of infant feeding experience. Large, long-term studies that extend into the period of solid food introduction that can temporally disentangle the link between appetitive traits and growth outcomes are needed.

Funding Sources: NICHD; Massachusetts Life Sciences Center