Abstract
BACKGROUND: Recent technologies have changed screen time. TV can be viewed anywhere, anytime. Content can be collected via digital recorders and online streaming and viewed on smartphones. Video games are no longer strictly sedentary. OBJECTIVES: We sought to assess the unknown relations between new modes of TV viewing - recorded, online, downloaded and on hand-held devices - and active video games with body mass index (BMI). METHODS: Cross-sectional analysis of the 2011 wave of the Growing Up Today Study 2 cohort. We used gender-specific generalized estimating equations to examine screen time and BMI among 3071 women and 2050 men aged 16-24 years. RESULTS: Among women, each hour/day of online TV (0.47; confidence interval [CI]: 0.12, 0.82) and total non-broadcast TV (0.37; CI: 0.14, 0.61) was associated with higher BMI, as was watching ≥ 1/2 h week(-1) of TV on hand-held devices (1.04; CI: 0.32-1.77). Active video games were associated with BMI among women, but not after restricting to those not trying to lose/maintain weight. Broadcast TV was associated with higher BMI (kg m(-2) ) among women and men (P < 0.05). CONCLUSIONS: Among women, online TV, TV viewed on hand-held devices and the sum of non-broadcast TV time were associated with higher BMI. Broadcast TV was also associated with BMI in women and men.