title: Early child care and obesity at 12 months of age in the Danish National Birth Cohort.
abstract: OBJECTIVE
  Evidence suggests that the child care environment may be more obesogenic than the family home, and previous studies have found that child care use may be associated with obesity in children. Few studies, however, have focused on child care during infancy, which may be an especially vulnerable period. This study examined child care use in infancy and weight status at 12 months of age in a country where paid maternity leave is common and early child care is not as prevalent as in other developed countries.
  
  
  METHODS
  We studied 27,821 children born to mothers participating in the Danish National Birth Cohort, a longitudinal study of pregnant women enrolled between 1997 and 2002, who were also included in the Childcare Database, a national record of child care use in Denmark. The exposure was days in child care from birth to 12 months. The outcomes were sex-specific body mass index (BMI) z-score and overweight/obesity (BMI ⩾ 85th percentile based on the World Health Organization classification) at 12 months. We conducted multivariable linear and logistic regression analyses examining child care use and weight outcomes.
  
  
  RESULTS
  A total of 17,721 (63.7%) children attended child care during their first year of life. After adjustment for potential confounders, a 30-day increment of child care was associated with a modestly higher BMI z-score at 12 months (0.03 units; 95% confidence interval (CI) = 0.01, 0.05; P=0.003). Similarly, child care use was associated with increased odds of being overweight/obese at 12 months of age (odds ratio = 1.05; 95% CI = 1.01, 1.10; P=0.047).
  
  
  CONCLUSIONS
  Child care in the first year of life was associated with slightly higher weight at 12 months, suggesting that child care settings may be important targets for obesity prevention in infancy.
authors.affiliation: Department of Community and Family Medicine, Duke University Medical Center and Duke Global Health Institute, Durham, NC, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Benjamin Neelon
authors.affiliation: Institute of Preventive Medicine, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Schou Andersen
authors.affiliation: Institute of Preventive Medicine, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Schmidt Morgen
authors.affiliation: Department of Public Health, Section of Social Medicine, University of Copenhagen CSS, Copenhagen, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Kamper-Jørgensen
authors.affiliation: Obesity Prevention Program, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA.
authors.forename: E
authors.initials: E
authors.lastname: Oken
authors.affiliation: Obesity Prevention Program, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA.
authors.forename: M W
authors.initials: MW
authors.lastname: Gillman
authors.affiliation: 1] Institute of Preventive Medicine, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark [2] Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: T I A
authors.initials: TI
authors.lastname: Sørensen
mesh_terms: D003718:Denmark / Q000453:epidemiology; D004032:Diet / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007223:Infant; D007224:Infant Care; D008137:Longitudinal Studies; D008297:Male; D010988:Play and Playthings; D015995:Prevalence; D012307:Risk Factors; D057185:Sedentary Behavior; D012959:Socioeconomic Factors; D015430:Weight Gain