title: Screen time and adiposity in adolescents in Mexico.
abstract: OBJECTIVE
  To assess the association of time spent viewing television, videos and video games with measures of fat mass (BMI) and distribution (triceps and subscapular skinfold thicknesses (TSF, SSF)).
  
  
  METHODS
  Cross-sectional validated survey, self-administered to students to assess screen time (television, videos and video games) and lifestyle variables. Trained personnel obtained anthropometry. The association of screen time with fat mass and distribution, stratified by sex, was modelled with multivariable linear regression analysis, adjusting for potential confounders and correlation of observations within schools.
  
  
  METHODS
  State of Morelos, Mexico.
  
  
  METHODS
  Males (n 3519) and females (n 5613) aged 11 to 18 years attending urban and rural schools in Morelos.
  
  
  RESULTS
  In males, screen time of >5 h/d compared with <2 h/d was significantly associated with a 0.13 (95% CI 0.04, 0.23) higher BMI Z-score, 0.73 mm (95% CI 0.24, 1.22) higher SSF and 1.08 mm (95% CI 0.36, 1.81) higher TSF. The positive association of screen time with SSF was strongest in males aged 11-12 years. Sexual maturity appeared to modify the association in females; a positive association between screen time and SSF was observed in those who had not undergone menarche (P for trend = 0.04) but not among sexually mature females (P for trend = 0.75).
  
  
  CONCLUSIONS
  Screen time is associated with fat mass and distribution among adolescent males in Mexico. Maturational tempo appears to affect the relationship of screen time with adiposity in boys and girls. Findings suggest that obesity preventive interventions in the Mexican context should explore strategies to reduce screen time among youths in early adolescence.
authors.affiliation: Center for Population Health Research, National Institute of Public Health, Av. Universidad 655, Col. Santa Maria Ahuacatitlán, CP 62508, Cuernavaca, Morelos, Mexico.
authors.forename: Martín
authors.initials: M
authors.lastname: Lajous
authors.forename: Jorge
authors.initials: J
authors.lastname: Chavarro
authors.forename: Karen E
authors.initials: KE
authors.lastname: Peterson
authors.forename: Bernardo
authors.initials: B
authors.lastname: Hernández-Prado
authors.forename: Aurelio
authors.initials: A
authors.lastname: Cruz-Valdéz
authors.forename: Mauricio
authors.initials: M
authors.lastname: Hernández-Avila
authors.forename: Eduardo
authors.initials: E
authors.lastname: Lazcano-Ponce
mesh_terms: D000273:Adipose Tissue; D050154:Adiposity; D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008572:Menarche; D008800:Mexico / Q000453:epidemiology; D009765:Obesity / Q000453:epidemiology / Q000209:etiology*; D012737:Sex Factors; D046468:Sexual Development; D012885:Skinfold Thickness; D013690:Television / Q000706:statistics & numerical data*; D013997:Time Factors; D018910:Video Games / Q000706:statistics & numerical data*; D014741:Video Recording / Q000706:statistics & numerical data