title: Viewing as little as 1 hour of TV daily is associated with higher change in BMI between kindergarten and first grade.
abstract: OBJECTIVE
  Evaluate associations between TV viewing and weight status in children from kindergarten to first grade.
  
  
  METHODS
  Linear and logistic regression was used to evaluate associations of TV-viewing time on BMI-z-score cross-sectionally at kindergarten and first grade and longitudinally in between, among a nationally representative sample of 14,645 children from the Early Childhood Longitudinal Study-Kindergarten Cohort 2011. All analyses were adjusted for sex, race/ethnicity, parental education, and household income.
  
  
  RESULTS
  Weekday TV-viewing time was correlated with BMI-z-score (P < 0.01) at kindergarten and first grade and with change in BMI-z-score in between (P < 0.05). Compared with children watching <1 h of TV daily, children watching ≥1 h in kindergarten and first grade had a greater odds of overweight (1.50-1.60) and obesity (1.58-1.73). Children watching 1-<2 h and ≥2 h daily had higher BMI-z-scores (P < 0.0001) and less favorable changes in BMI-z-score between time points (P < 0.05). Children who were not overweight or obese in kindergarten and watched ≥1 h of TV had a greater odds of becoming overweight (1.39) and obese (1.86) between evaluations.
  
  
  CONCLUSIONS
  Children watching as little as 1-<2 h of TV daily were more likely to become overweight and obese over time. Physicians should encourage families to restrict TV-viewing time to reduce weight gain.
authors.affiliation: Division of Pediatric Endocrinology, University of Virginia, Charlottesville, Virginia, USA.|Department of Pediatrics, University of Virginia, Charlottesville, Virginia, USA.
authors.forename: Travis
authors.initials: T
authors.lastname: Peck
authors.affiliation: Department of Pediatrics, University of Virginia, Charlottesville, Virginia, USA.|Division of Developmental Pediatrics, University of Virginia, Charlottesville, Virginia, USA.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Scharf
authors.affiliation: Department of Public Health Sciences, University of Virginia, Charlottesville, Virginia, USA.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Conaway
authors.affiliation: Division of Pediatric Endocrinology, University of Virginia, Charlottesville, Virginia, USA.|Department of Pediatrics, University of Virginia, Charlottesville, Virginia, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: DeBoer
mesh_terms: D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009765:Obesity / Q000209:etiology*; D013690:Television / Q000639:trends*; D013997:Time Factors; D015430:Weight Gain / Q000502:physiology*