Location: Arkansas Children's Nutrition CenterTitle: Body composition of infants fed breast-milk, milk-based formula or soy-based formula during the first 6 months of life Author
Submitted to: Obesity
Publication Type: Abstract Only
Publication Acceptance Date: 6/30/2008
Publication Date: 10/15/2008
Citation: Gilchrist, J.M., Andres, A., Badger, T.M. 2008. Body composition of infants fed breast-milk, milk-based formula or soy-based formula during the first 6 months of life [abstract]. Obesity. 16(S1):434P. Interpretive Summary:
Technical Abstract: Literature on the impact of infant feeding on body composition is sparse and inconclusive. We assessed body composition in infants exclusively fed breast-milk (BF), milk-based formula (MF) or soy-based formula (SF) for at least the first 4 months of life. Participants are part of the on-going prospective, longitudinal Beginnings study. Body composition was assessed using air displacement plethysmography (PEA POD; Life Measurement Inc, Concord, CA) at 2, 3, 4, 5. and 6 months of age (N=78, 76, 71, 51. and 31, respectively). The PEA POD is designed for infants age birth to 6 months, weighing 1-8 kg; missing data were due to infants exceeding the weight capacity. Anthropometrics were measured at every visit using standard techniques. Weight-for-length (WL), weight-for-age (WA), and height-for-age (HA) Z-scores were calculated using Epi Info (CDC, Version 3.4.1). Due to gender differences in body composition, boys and girls data were analyzed separately. Among boys, %Fat, fat mass (kg), fat free mass (kg), weight, length, WH, WA, and HA Z-scores were not significantly different between BF, MF, and SF infants at any time point. Among girls, %Fat was significantly different at 6 months between BF and MF (28.4 +/- 1.6 vs. 23.1 +/- 1.6). Fat free mass (kg) was also significantly different between BF and MF at 4, 5, and 6 months (4.5 +/- 0.1 vs. 4.9 +/- 0.1, 4.7 +/- 0.1 vs. 5.3 +/- 0.1, and 4.9 +/- 0.1 vs. 5.6 +/- 0.1, respectively). Finally, WA Z-scores were significantly different between BF and MF at 5 months (-0.13 +/- 0.2 vs. 0.5 +/- 0.1). Fat mass (kg), weight, length, WH and HA Z-scores were not different among the groups at any time point. Our data suggest that infant diet does not differentially impact growth or body composition during the first 3 months of life. Between 4 and 6 months, fat free mass of MF girls was higher than BF girls. In addition, %Fat was higher in BF than MF girls at 6 months. The period of 4–6 months, when complementary foods are added to infant diets, may be a critical window for development, and therefore possible prevention, of childhood obesity. Further study with different body composition methods will be valuable to confirm these findings, since attrition due to the weight limit of the PEA POD may introduce a bias.