title: Increased television viewing is associated with elevated body fatness but not with lower total energy expenditure in children.
abstract: BACKGROUND
  Television (TV) viewing in children is associated with a higher body mass index, but it is unknown whether this reflects body fatness, and, if it does, why.
  
  
  OBJECTIVE
  The objective was to investigate whether TV viewing is associated with body fatness, physical activity, and total energy expenditure in preschool children.
  
  
  METHODS
  Eighty-nine children were recruited into a cross-sectional study. Total daily energy expenditure (TEE) was measured by doubly labeled water, body composition by dual-energy X-ray absorptiometry, and physical activity by accelerometry.
  
  
  RESULTS
  There was a significant positive association between fat mass (corrected for fat-free body mass) and TV viewing (F = 9.05, P = 0.004). Each extra hour of watching TV was associated with an extra 1 kg of body fat. Children who watched more TV were also significantly less physically active (F = 5.16, P = 0.026). Independent of body composition and sex, children with greater physical activity levels had higher TEE (F = 5.15, P = 0.029); however, physical activity did not mediate the relation between TV viewing and adiposity (P > 0.05).
  
  
  CONCLUSIONS
  Preschool children who watch more TV are fatter and are less active, and activity influences TEE. However, despite TV viewing being linked to lower physical activity, the relation between TV viewing and fatness is not mediated by physical activity. The results suggest that a relation between TV viewing and fatness is more likely to be due to an effect on food intake.
authors.affiliation: Division of Obesity and Metabolic Health, Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen, Scotland, UK. d.jackson@rowett.ac.uk
authors.forename: Diane M
authors.initials: DM
authors.lastname: Jackson
authors.forename: Kurosh
authors.initials: K
authors.lastname: Djafarian
authors.forename: Joanne
authors.initials: J
authors.lastname: Stewart
authors.forename: John R
authors.initials: JR
authors.lastname: Speakman
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000378:metabolism*; D001823:Body Composition / Q000502:physiology*; D001834:Body Water / Q000378:metabolism; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007553:Isotope Labeling; D008019:Life Style; D008297:Male; D009765:Obesity / Q000209:etiology; D010809:Physical Fitness / Q000502:physiology; D011795:Surveys and Questionnaires; D013690:Television; D013997:Time Factors