The objective of this study was to investigate the associations of mode of feeding with infant anthropometric and body composition variables at 6 months of age. We studied 259 infants whose exclusive mode of feeding (breast or formula) to 1 month was confirmed. Standard anthropometric characteristics of the infants (weight, length and weight-for-length z scores) were obtained, and body composition (total fat mass, fat-free mass, trunk fat mass and body fat percent) was measured using dual-energy X-ray absorptiometry (DXA) at 6 months (±12 days). General linear models were used to test the associations of mode of feeding with infant anthropometric and body composition variables at 6 months after adjustment for maternal and infant covariates. In this cohort of predominantly breastfed, White infants of highly educated mothers, fat-free mass was lower (P =.002), and trunk fat mass (P =.032) and body fat percent (P <.001) were greater in breastfed infants than in formula-fed infants at 6 months of age. After adjustment for covariates, total fat-free mass was significantly lower (β = −372 g, [SE = 125, P =.003]), and body fat percent was significantly greater (β = 3.30, [SE = 0.91, P <.001]) in breastfed infants than in formula-fed infants. No other significant associations were observed. These findings support those of previous studies reporting greater fat-free mass in formula-fed infants during the first 6 months of life. Additional research is warranted to explore whether differences in infant body composition by mode of feeding persist throughout the life course and to assess causality.
Bibliographical noteFunding Information:
KE is supported by the Japan Society for the Promotion of Science 18K18146; DBA is supported by the National Heart, Lung, and Blood Institute R25HL12420; MJT is supported by the National Heart, Lung, and Blood Institute T32HL007779; EWD and DAF are supported by the National Institute of Child Health and Human Development R01HD080444.
© 2020 The Authors. Maternal & Child Nutrition published by John Wiley & Sons Ltd
- body composition
- childhood obesity
- early growth
- infant formula