Duration of television watching is associated with increased body mass index.
OBJECTIVE
To assess the effect of television viewing on subsequent change in body mass index (BMI=kg/m(2)) percentiles (BMI%) in adolescence.


METHODS
Data were drawn from the California Teen Longitudinal Survey of adolescents 12 to 17 years old with baseline assessment in 1993 and follow-up in 1996. Self-reported height and weight were used to calculate BMI and derive age-specific and sex-specific BMI%. Hours of television watched per day were obtained at baseline (BTV). The relations of BTV and BMI percentiles both at baseline and after 3 years were assessed with linear regression modeling.


RESULTS
Of 2223 adolescents (52% male, 68% white), 5.85% (n=130) were overweight (BMI > or =95th percentile) at baseline and 5.40% (n=120) at follow-up. Mean BTV was 2.85 (SD, 1.98). In adjusted models, with each additional hour of BTV, the baseline BMI% increased by.9, and the follow-up BMI% increased by.47. Adolescents who watched more than 2 hours of television a day were twice as likely to be overweight at follow-up as adolescents who watched < or =2 hours.


CONCLUSIONS
Television viewing leads to a subsequent increase in BMI percentiles and overweight. Efforts to decrease overweight should consider interventions to reduce television time.
Department of Pediatrics, Medical Center, University of Kansas School of Medicine, Mailstop 1008, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA. hkaur@kumc.edu
Harsohena
H
Kaur
Won S
WS
Choi
Matthew S
MS
Mayo
Kari Jo
KJ
Harris
D000293:Adolescent; D015992:Body Mass Index; D001835:Body Weight; D005260:Female; D006801:Humans; D007899:Leisure Activities; D016015:Logistic Models; D008297:Male; D013690:Television; D013997:Time Factors