title: Does breastfeeding protect against childhood overweight? Hong Kong's 'Children of 1997' birth cohort.
abstract: BACKGROUND
  Observational studies from mainly Western settings suggest breastfeeding may protect against childhood adiposity; however, breastfeeding and adiposity share social patterning potentially generating confounding, making evidence from other settings valuable.
  
  
  METHODS
  We used multivariable linear regression to examine the prospective adjusted associations of breastfeeding with body mass index (BMI), height and weight z-scores at 7 years of age relative to the 2007 World Health Organization (WHO) growth reference, in a large (n = 8327), population-representative Hong Kong Chinese birth cohort, recruited between April and May 1997 with high follow-up (n = 7026).
  
  
  RESULTS
  Low socio-economic position (SEP) was associated with never breastfeeding and with exclusive breastfeeding for > or =3 months. We did not find any association between breastfeeding and BMI [z-score mean difference 0.07, 95% confidence interval (CI) -0.05 to 0.19], height (0.02, 95% CI -0.07 to 0.11) or weight (0.07, 95% CI -0.05 to 0.18), adjusted for sex, birth weight, gestational age, SEP, second-hand smoke (SHS) exposure, parity, mother's age at birth, mother's place of birth and serious infant morbidity.
  
  
  CONCLUSIONS
  In a non-European setting, breastfeeding was not associated with child adiposity, suggesting that observed protective effects may be due to socially patterned confounding by SEP, maternal adiposity and maternal smoking.
authors.affiliation: Department of Community Medicine and School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Man Ki
authors.initials: MK
authors.lastname: Kwok
authors.forename: C Mary
authors.initials: CM
authors.lastname: Schooling
authors.forename: Tai Hing
authors.initials: TH
authors.lastname: Lam
authors.forename: Gabriel M
authors.initials: GM
authors.lastname: Leung
mesh_terms: D015992:Body Mass Index; D001837:Body Weights and Measures; D001942:Breast Feeding; D002648:Child; D002657:Child Development; D015331:Cohort Studies; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D016014:Linear Models; D008297:Male; D050177:Overweight / Q000453:epidemiology*; D012959:Socioeconomic Factors