Adiposity and different types of screen time

Abstract

Objective: Few prospective studies have examined separate forms of screen time in relation to adiposity. Our objective was to assess independent relations of television, electronic games (video/computer), and digital versatile disc (DVD)/videos and total screen time with change in adolescent BMI.

Methods: Using data from the 2004, 2006, and 2008 waves of the ongoing Growing up Today Study II, we assessed baseline and 2-year change in reported screen time in relation to concurrent change in BMI among 4287 girls and 3505 boys aged 9 to 16 years in 2004. Gender-specific models adjusted for previous BMI, age, race/ethnicity, growth/development, months between questionnaires, and physical activity.

Results: Among girls and boys, each hour per day increase in reported television viewing was associated with a 0.09 increase in BMI (Ps < .001), and each hour per day increase in total screen time was associated with a 0.07 increase among girls and 0.05 increase among boys (Ps < .001). Among girls only, greater baseline television, games, and total screen time and change in DVDs/videos were associated with gains in BMI (Ps < .05). BMI gains associated with change in television and total screen time were stronger among overweight girls than lean girls (Ps-heterogeneity < .001).

Conclusions: Television, which remains the steadiest source of food advertising, was most consistently associated with BMI gains. Among girls, electronic games and DVDs/videos were also related to increased BMI, possibly due to influences of product placements and advergames on diet and/or distracted eating. Adolescents, especially overweight adolescents, may benefit from reduced time with multiple types of media.

Keywords: BMI; adiposity; adolescent; body weight; longitudinal studies; sedentary lifestyle; television; video games.

FIGURE 1

Predicted means of change in BMI from gender-stratified fully adjusted models, including restricted cubic spline terms for change in hours per day (h/d) of total reported screen time with knots at the 5th, 25th, 50th, 75th, and 95th percentile of change in total reported screen time. Models adjusted for age, age², baseline BMI, height change, Tanner stage, menarcheal status (yes/no) for girls, months between questionnaires, non-Hispanic white (yes/no), recreational moderate-to-vigorous physical activity (h/wk) and change in physical activity (h/wk), and baseline total reported screen time (h/d).