title: Fatness, physical activity, and television viewing in children during the adiposity rebound period: the Iowa Bone Development Study.
abstract: BACKGROUND
  Understanding the determinants of adiposity in young children may be particularly critical for preventing adult obesity since the age at which body fatness reaches a postinfancy low point (typically 4-6 years) is inversely associated with obesity later in life. METHODS; We examined cross-sectional associations among fatness, leanness, and physical activity in 467 children (range 4-6 years). Activity was measured using accelerometry and parental report of children's television (TV) viewing. Dual energy X-ray absorptiometry was used to quantify body composition.
  
  
  RESULTS
  Minutes spent in vigorous activity and TV viewing were the variables most consistently and most highly associated with adiposity. Children in the lowest quartile for vigorous activity had on average (absolute) body fat percentages that were 4% greater than those children in the highest quartile for vigorous activity. Body fat percentages for children in the highest category for TV viewing were on average 3% greater than those children who watched the least amount of TV.
  
  
  CONCLUSIONS
  Low levels of vigorous physical activity and high levels of TV viewing are associated with fatness in young children during the adiposity rebound period. This suggests that increasing children's active play may be important in preventing obesity later in life.
authors.affiliation: Department of Health and Sport Studies, 102 FH, The University of Iowa, Iowa City, IA 52242, USA. kathleen-janz@uiowa.edu
authors.forename: Kathleen F
authors.initials: KF
authors.lastname: Janz
authors.forename: Steven M
authors.initials: SM
authors.lastname: Levy
authors.forename: Trudy L
authors.initials: TL
authors.lastname: Burns
authors.forename: James C
authors.initials: JC
authors.lastname: Torner
authors.forename: Marcia C
authors.initials: MC
authors.lastname: Willing
authors.forename: John J
authors.initials: JJ
authors.lastname: Warren
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000502:physiology; D000886:Anthropometry; D001823:Body Composition / Q000502:physiology; D001846:Bone Development / Q000502:physiology; D002648:Child; D002669:Child Welfare; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007484:Iowa / Q000453:epidemiology; D007899:Leisure Activities; D008297:Male; D009765:Obesity / Q000453:epidemiology* / Q000517:prevention & control; D013690:Television / Q000706:statistics & numerical data*