|Hopkinson, Judy - BAYLOR COLL OF MEDICINE|
|Smith, O'Brian - BAYLOR COLL OF MEDICINE|
Submitted to: Pediatrics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 2, 2000
Publication Date: N/A
Interpretive Summary: Breast-fed infants have different growth patterns than formula-fed infants. Breast-fed infants consume less energy and protein and fewer micronutrients, and tend to gain less weight. We wanted to determine the effect of nutrient intake differences on the body composition of breast-fed versus formula-fed infants, and to find out whether any such body composition differences persist past weaning. We studied infants on both feeding modes over the first 2 years of life. Our evaluation methods at different time points included a body composition model involving measurements of total body water and potassium and bone mineral content, total body electrical conductivity and dual-energy X-ray absorptiometry. The results showed weight gain was faster in formula-fed infants at 3-6 months, and formula-fed girls at 6-9 months. Differences in weight gain and body composition coincident with nutrient intake differences were observed in the suckling period of early infancy. Breast-fed infants tended to have higher fat mass and lower fat-free mass in the first year of life. With the introduction of other milks and foods, differences in body composition between feeding groups lessened and were no longer seen in the second year of life. We conclude that the type of feeding mode is associated with body composition differences in early infancy that do not persist into the second year of life. This information will be extremely useful to researchers and clinicians in evaluating the appropriate nutrition and development of babies.
Technical Abstract: Background: Differences in the growth pattern of breast-fed (BF) and formula-fed (FF) infants are well-recognized and have been attributed to differences in nutrient intake. However, the impact of qualitative and quantitative differences in nutrient intake on the body composition of BF and FF infants is unclear. Furthermore, it is unknown if putative differences in body composition persist beyond weaning. Design: Prospectiv cohort study. Repeated anthropometric and body composition measurements were performed on 40 BF and 36 FF infants at 0.5, 3, 6, 9, 12, 18 and 24 mo of age. A multicomponent body composition model was used to estimate fat free mass (FFM) and fat mass (FM). Infant food intake was measured at 3, 6, 12 and 24 mo of age using 3-d weighed-intake records. Weight velocity was higher in FF than BF infants 3-6 mo, and higher in FF than BF girls 6-9 mo of age (P=0.04). Adjusted for gender and baseline values, BF infants had lower TBW at 3 mo (P=0.02), TBK at 3-24 mo (P=0.04) and BMC at 12 mo (P=0.04). The multicomponent model indicated that FFM was lower in BF than FF infants at 3 mo (P=0.01), and FM and %FM were higher in BF than FF infants at 3 (P=0.02) and 6 mo (boys only, P=0.05). TOBEC confirmed lower FFM in BF than FF infants at 3 mo, as well as at 6 and 9 mo; FM and %FM were higher in BF than FF at 3 and 6 mo (P less than or equal to 0.03), and 9 mo (boys only, P=0.05). Intakes of energy, protein, fat and carbohydrate were lower in BF than FF infants at 3 and 6 mo (P=0.001), and were positively correlated with weight gain and FFM gain, but not FM gain. No differences in nutrient intakes were observed at 12 or 24 mo. Conclusion: Infant feeding mode is associated with differences in body composition in early infancy which do not persist into the second year of life.