Association between screen time and accelerometer-measured 24-h movement behaviors in a sample of Brazilian adolescents

Objectives: Different screen time activities may be related to sleep, physical activity, and sedentary behavior. The objective was to examine the association between self-reported screen time activities and accelerometer-measured 24-h movement behaviors. Study design: This was a cross-sectional study. Methods: Adolescents' (n = 718, 50.4% girls, 16 years) sleep duration, sedentary behavior, light-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) were estimated with wrist-worn accelerometry. Time spent on screen time activities related to studying, working, watching videos, playing video games, and using social media was self-reported. Multilevel linear regressions were used to test the association between screen time with sleep, sedentary behavior, and physical activity. Results: Boys and girls slept 6.4 and 6.7 h per night, spent 10.4 and 10.1 h/d in sedentary behavior, spent 4.0 and 4.4 h/d in LPA, and spent 34.7 and 29.2 min/d in MVPA, respectively. Studying was inversely related to LPA and MVPA. Working was inversely related to sleep and positively related to LPA. Watching videos was associated with lower LPA and MVPA. For boys, videogames were associated with increased sedentary behavior and lower LPA and MVPA. For girls, studying and/or using social media were associated with lower LPA and MVPA. Conclusions: Indicators of screen time were associated with different accelerometer-measured 24-h movement behaviors in this sample of Brazilian adolescents. (C) 2021 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.