Longitudinal associations between screen time and whole-body adiposity during the first decade of life: insights from the GUSTO cohort.

BACKGROUND/

OBJECTIVES

Childhood obesity remains a pressing public health challenge worldwide. With screen viewing emerging as a major contributor to sedentary time, it is crucial to assess the extent to which screen viewing contributes to excessive body fat in children. The aim of this study was to examine the associations between screen time and subsequent adiposity in children from the Singapore GUSTO cohort.

SUBJECTS/

METHODS

At ages 2 and 3 years, parents reported their child's screen time, including television and handheld devices. Body fat was assessed repeatedly between ages 4 and 10 years using various methods, including body mass index (BMI), BMI z-score (zBMI), skinfold thicknesses, and whole-body body fat percentage using air displacement plethysmography (BOD POD®) and/or quantitative magnetic resonance (EchoMRITM). Among 935 children, we examined associations between average screen time from 2-3 years and adiposity using generalized estimating equations, adjusted for potential confounders and stratified by child sex.

RESULTS

The average ( ± SD) screen time at 2-3 years was 2.5 ( ± 1.8) h/day. At 8 years, average body fat percentage measured by BOD POD® was 21.8% ( ± 9.1) in boys and 20.5% ( ± 8.9) in girls. In the overall sample, there were no associations between screen viewing time and adiposity. However, each one-hour increase in total screen time (β [95% CI] = 0.40 [0.05, 0.75] % per h/day) and television time (0.55 [0.10, 1.00] %) was associated, among boys, with greater whole-body fat percentage from 4 to 9 years. Consistent associations were found with skinfold thicknesses, but not with BMI/zBMI. No associations were found with handheld device time, nor among girls.

CONCLUSIONS

Greater screen time, notably television time, was prospectively associated with greater adiposity among boys, but not in girls. Future studies should investigate the potential mediating mechanisms involved in this sex-specific relationship.

STUDY REGISTRATION: This cohort study was registered on the 4th of August, 2010 and is available online at ClinicalTrials.gov: NCT01174875.