title: Macronutrient composition of human milk from Korean mothers of full term infants born at 37-42 gestational weeks.
abstract: OBJECTIVE
  Breast milk is the best available food for optimum growth and development of infants and the breastfeeding rate is increasing in Korea. The purpose of this study is to measure the concentrations of macronutrients and to evaluate their changes according to lactation period in breast milk from lactating Korean women.
  
  
  METHODS
  Milk samples were obtained from 2,632 healthy lactating women (mean age; 32.0 ± 3.3 years), where the lactating period was up to a period of 8 months, who also volunteered to participate in the Human Milk Macronutrient Analysis Research. Lactose, protein, fat and water content in the breast milk samples were analyzed with infrared spectrometry using MilkoScan FT-2.
  
  
  RESULTS
  The mean macronutrient composition per 100 mL of mature breast milk was 7.1 g for lactose, 1.4 g for protein and 3.0 g for fat, and energy content was 61.1 kcal. The protein concentration was significantly lower in milk samples at 1-2 weeks (2.0 g/dL) to 2-3 months (1.4 g/dL) than those at 0-1 week (2.2 g/dL), but it was similar among samples from 3-4 months to 7-8 months (1.3 g/dL). Mean lipid levels varied among different lactational period groups (2.7-3.2 g/dL), but presented no significant difference. Lactose concentration in the milk samples did not differ with lactation period. Maternal body mass index was positively related to protein and lipid breast milk contents, but was negatively related to lactose content. General linear models examining the associations between maternal variables and milk macronutrient content revealed that lactation period had a major impact on protein and lipid, but not on lactose content in breast milk.
  
  
  CONCLUSIONS
  These results warrant future studies to explore factors that may be associated with changes in macronutrient content in human milk.
authors.affiliation: Department of Nutritional Science and Food Management, Ewha Womans University, 52, Ewhayeodae-gil, Seodaemun-gu, Seoul 120-750, Korea.
authors.forename: Namsoo
authors.initials: N
authors.lastname: Chang
authors.affiliation: Maeil Human Milk R & D Center, Maeil Dairies Co., Seoul 110-150, Korea.
authors.forename: Ji A
authors.initials: JA
authors.lastname: Jung
authors.affiliation: Department of Nutritional Science and Food Management, Ewha Womans University, 52, Ewhayeodae-gil, Seodaemun-gu, Seoul 120-750, Korea.
authors.forename: Hyesook
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Nutritional Science and Food Management, Ewha Womans University, 52, Ewhayeodae-gil, Seodaemun-gu, Seoul 120-750, Korea.
authors.forename: Ara
authors.initials: A
authors.lastname: Jo
authors.affiliation: Maeil Human Milk R & D Center, Maeil Dairies Co., Seoul 110-150, Korea.
authors.forename: Sujeong
authors.initials: S
authors.lastname: Kang
authors.affiliation: Maeil Human Milk R & D Center, Maeil Dairies Co., Seoul 110-150, Korea.
authors.forename: Si-Won
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Maeil Human Milk R & D Center, Maeil Dairies Co., Seoul 110-150, Korea.
authors.forename: Hyunju
authors.initials: H
authors.lastname: Yi
authors.affiliation: Maeil Human Milk R & D Center, Maeil Dairies Co., Seoul 110-150, Korea.
authors.forename: Jihee
authors.initials: J
authors.lastname: Kim
authors.affiliation: Maeil Human Milk R & D Center, Maeil Dairies Co., Seoul 110-150, Korea.
authors.forename: Jong-Gap
authors.initials: JG
authors.lastname: Yim
authors.affiliation: Maeil Human Milk R & D Center, Maeil Dairies Co., Seoul 110-150, Korea.
authors.forename: Byung-Moon
authors.initials: BM
authors.lastname: Jung
keywords: BMI; Breast milk; lactation period; macronutrient