Screen time and adiposity among children and adolescents: a systematic review

Background The younger generation is witnessing a major lifestyle change due to the incorporation of a myriad digital devices into their daily lives. Susceptibility to screen exposure at an early age may have far-reaching effects on health outcomes. A review of various cross-cultural studies would help to ascertain the impacts of screen-based technologies on adiposity among children and adolescents. Objective To examine the relationship between screen time and indicators of adiposity among children and adolescents, based on a systematic review of previous research carried out in this area around the world. Methods Articles in English language from 2010 to 2017 were selected through web databases such as Google Scholar, Science Direct, Research Gate, Pub Med, etc. Published empirical research works that demonstrated the association between screen time or sedentary time and adiposity measures such as BMI, percentage of body fat, and waist circumference were included for review. The search was limited to boys and girls aged 5-19 years. For this review, 235 full-text articles were collected, out of which only 40 met the inclusion criteria. Of 40 selected studies, 36 had reported results for BMI, seven for percentage of body fat, and 13 for waist circumference. With regard to screen-related activities, data were obtained mainly for TV viewing (n = 18), computer use (n = 11), video game playing (n = 5) and Internet use (n = 1). Result Among the studies selected for review, 85% (31 cross-sectional, six longitudinal and one interventional, i.e. n = 38) indicated positive association between screen time and incidences of adiposity among children and adolescents. However, 15% (n = 6) of the studies (four cross-sectional, one longitudinal and one interventional) reported no significant associations between time spent on screen devices and any of the indicators of adiposity. None of the studies showed a negative association. Age- and gender-related differences were also seen in usage of screen-based technologies and related activities. Conclusion Reducing overall use of screen technologies and displacing it with other active pursuits, increasing sleep duration, and promoting healthy lifestyle behaviors could be an effective approach to attenuate increased risks of overweight or obesity and improve health of children and adolescents.