title: Early life course risk factors for childhood obesity: the IDEFICS case-control study.
abstract: BACKGROUND
  The early life course is assumed to be a critical phase for childhood obesity; however the significance of single factors and their interplay is not well studied in childhood populations.
  
  
  OBJECTIVE
  The investigation of pre-, peri- and postpartum risk factors on the risk of obesity at age 2 to 9.
  
  
  METHODS
  A case-control study with 1,024 1:1-matched case-control pairs was nested in the baseline survey (09/2007-05/2008) of the IDEFICS study, a population-based intervention study on childhood obesity carried out in 8 European countries in pre- and primary school settings. Conditional logistic regression was used for identification of risk factors.
  
  
  RESULTS
  For many of the investigated risk factors, we found a raw effect in our study. In multivariate models, we could establish an effect for gestational weight gain (adjusted OR = 1.02; 95%CI 1.00-1.04), smoking during pregnancy (adjusted OR = 1.48; 95%CI 1.08-2.01), Caesarian section (adjusted OR = 1.38; 95%CI 1.10-1.74), and breastfeeding 4 to 11 months (adjusted OR = 0.77; 95%CI 0.62-0.96). Birth weight was related to lean mass rather than to fat mass, the effect of smoking was found only in boys, but not in girls. After additional adjustment for parental BMI and parental educational status, only gestational weight gain remained statistically significant. Both, maternal as well as paternal BMI were the strongest risk factors in our study, and they confounded several of the investigated associations.
  
  
  CONCLUSIONS
  Key risk factors of childhood obesity in our study are parental BMI and gestational weight gain; consequently prevention approaches should target not only children but also adults. The monitoring of gestational weight seems to be of particular importance for early prevention of childhood obesity.
authors.affiliation: Institute for Public Health and Nursing Research (IPP), University of Bremen, Bremen, Germany ; BIPS Institute for Prevention Research and Epidemiology, Bremen, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Bammann
authors.affiliation: BIPS Institute for Prevention Research and Epidemiology, Bremen, Germany.
authors.forename: Jenny
authors.initials: J
authors.lastname: Peplies
authors.affiliation: Department of Public Health, Ghent University, Ghent, Belgium.
authors.forename: Stefaan
authors.initials: S
authors.lastname: De Henauw
authors.affiliation: Department of Public Health and Community Medicine, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Monica
authors.initials: M
authors.lastname: Hunsberger
authors.affiliation: Department of Pediatrics, University of Pécs, Pécs, Hungary.
authors.forename: Denes
authors.initials: D
authors.lastname: Molnar
authors.affiliation: Growth, Exercise, Nutrition and Development (GENUD) Research Group, University of Zaragoza, Zaragoza, Spain.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Moreno
authors.affiliation: Research and Education Foundation of Child Health, Strovolos, Cyprus.
authors.forename: Michael
authors.initials: M
authors.lastname: Tornaritis
authors.affiliation: Department of Chronic Diseases, National Institute for Health Development, Tallinn, Estonia.
authors.forename: Toomas
authors.initials: T
authors.lastname: Veidebaum
authors.affiliation: BIPS Institute for Prevention Research and Epidemiology, Bremen, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Ahrens
authors.affiliation: Unit of Epidemiology and Population Genetics, Institute of Food Sciences, National Research Council, Avellino, Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Siani
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001942:Breast Feeding; D016022:Case-Control Studies; D002585:Cesarean Section; D002648:Child; D002675:Child, Preschool; D005060:Europe; D005260:Female; D020567:Fetal Weight; D005865:Gestational Age; D006801:Humans; D016015:Logistic Models; D008297:Male; D063766:Pediatric Obesity / Q000175:diagnosis* / Q000503:physiopathology; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012307:Risk Factors; D012907:Smoking; D015430:Weight Gain