title: Effect of activity and television viewing on BMI z-score in early adolescents in Turkey.
abstract: BACKGROUND
  television, computer and other causes of increased inactivity are reported to be among the major causes of obesity. This cross-sectional study was aimed to evaluate the effect of television viewing and other daily activities on body mass index (BMI) z-score of early adolescents.
  
  
  METHODS
  a total of 860 students and their parents (581) from different socioeconomic level schools were included. They were instructed to fill in a self-designed questionnaire. Weight and height were measured, and BMI z-scores were calculated.
  
  
  RESULTS
  BMI z-score was higher in boys and in those attending high socioeconomic level schools. Children with a BMI z-score >2SD watched television (2.5 ± 0.9 h/day) longer than those with <-2SD (1.6 ± 0.8 h/day) (P=0.027). The three categories (<-2SD, -2SD-2SD, >2SD) differed significantly according to maternal (P<0.05) and paternal (P<0.005) BMI. Linear logistic regression analysis revealed that socioeconomic level, maternal BMI and paternal BMI are factors affecting BMI z-score significantly.
  
  
  CONCLUSIONS
  genetic and/or family environment which may affect the nutrition and activity of adolescents seems to be the most important factor affecting their BMI z-score.
authors.affiliation: Department of Pediatrics, Social Pediatrics Unit, Hacettepe University Faculty of Medicine, Ankara, Turkey. nozmert@hacettepe.edu.tr
authors.forename: Elif N
authors.initials: EN
authors.lastname: Ozmert
authors.forename: Ramazan
authors.initials: R
authors.lastname: Ozdemir
authors.forename: Ayhan
authors.initials: A
authors.lastname: Pektaş
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Uçkardeş
authors.forename: Kadriye
authors.initials: K
authors.lastname: Yurdakök
mesh_terms: D000293:Adolescent; D000465:Algorithms; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D003201:Computers / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D006801:Humans; D008019:Life Style; D016014:Linear Models; D008297:Male; D009043:Motor Activity; D009765:Obesity / Q000453:epidemiology / Q000209:etiology*; D010290:Parents; D013334:Students / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D013690:Television / Q000706:statistics & numerical data*; D014421:Turkey / Q000453:epidemiology