title: Associations of infant feeding and timing of linear growth and relative weight gain during early life with childhood body composition.
abstract: BACKGROUND
  Growth and feeding during infancy have been associated with later life body mass index. However, the associations of infant feeding, linear growth and weight gain relative to linear growth with separate components of body composition remain unclear.
  
  
  METHODS
  Of 5551 children with collected growth and infant-feeding data in a prospective cohort study (Amsterdam Born Children and their Development), body composition measured using bioelectrical impedance analysis at the age of 5-6 years was available for 2227 children. We assessed how feeding (duration of full breastfeeding and timing of introduction of complementary feeding) and conditional variables representing linear growth and relative weight gain were associated with childhood fat-free mass (FFM) and fat mass (FM).
  
  
  RESULTS
  Birth weight was positively associated with both FFM and FM in childhood, and more strongly with FFM than FM. Faster linear growth and faster relative weight gain at all ages in infancy were positively associated with childhood FFM and FM. The associations with FM were stronger for relative weight gain than for linear growth (FM z score: β coefficient 0.23 (95% con 0.19 to 0.26), P<0.001 and 0.14 (0.11 to 0.17), P<0.001 per s.d. change in relative weight gain and linear growth between 1 and 3 months, respectively). Compared with full breastfeeding <1 month, full breastfeeding >6 months was associated with lower FM (FM z score: -0.17 (-0.28 to -0.05), P=0.005) and lower FFM (FFM z score: -0.13 (-0.23 to -0.03), P=0.015), as was the introduction of complementary feeding >6 months (FM z score: -0.22 (-0.38 to -0.07), P=0.004), compared with <4 months.
  
  
  CONCLUSIONS
  Faster infant weight gain is associated with a healthier childhood body composition when it is caused by faster linear growth. Full breastfeeding >6 months and introduction of complementary feeding >6 months are associated with lower childhood FM.
authors.affiliation: Department of Pediatrics, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: de Beer
authors.affiliation: Department of Social Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: T G M
authors.initials: TG
authors.lastname: Vrijkotte
authors.affiliation: MRC Lifecourse Epidemiology Unit, Southampton General Hospital, University of Southampton, Southampton, UK.
authors.forename: C H D
authors.initials: CH
authors.lastname: Fall
authors.affiliation: Department of Epidemiology, Documentation and Health Promotion, Public Health Service, Amsterdam, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: van Eijsden
authors.affiliation: MRC Lifecourse Epidemiology Unit, Southampton General Hospital, University of Southampton, Southampton, UK.
authors.forename: C
authors.initials: C
authors.lastname: Osmond
authors.affiliation: Department of Pediatrics, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: R J B J
authors.initials: RJ
authors.lastname: Gemke
mesh_terms: D001724:Birth Weight; D001823:Body Composition; D015992:Body Mass Index; D001903:Bottle Feeding / Q000706:statistics & numerical data*; D001942:Breast Feeding / Q000706:statistics & numerical data*; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D017097:Electric Impedance; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D006801:Humans; D007223:Infant; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011446:Prospective Studies; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D013997:Time Factors; D015430:Weight Gain / Q000502:physiology*