China's sedentary lifestyle law has increased physical activity in children
British researchers, along with Chinese colleagues, evaluated the impact of a Chinese law regulating children's access time to online games, the amount of homework in schools and tutoring loads on their physical activity levels. As reported in the International Journal of Behavioral Nutrition and Physical Activity, children had a 13.8 per cent reduction in total sedentary time and a 6.4 per cent reduction in total time in front of screens.
Sedentary lifestyle is defined as any behaviour during waking hours characterised by energy expenditure of less than 1.5 metabolic equivalents (the amount of energy expended by a person at rest and equivalent to burning one kilocalorie per kilogram per hour) while sitting or lying down. Evidence from systematic reviews, meta-analyses and longitudinal studies has shown that excessively sedentary lifestyles, including sedentary lifestyles based on large amounts of time in front of screens for entertainment purposes, affect multiple aspects of child and adolescent well-being, including mental health, cognitive function, quality of life and physical health.
In China, more than 60 per cent of schoolchildren use some of their sleep time to play games on mobile phones and watch videos, while 27 per cent use it for homework or other learning activities. In this way, their sedentary time increases and their sleep time decreases, which negatively affects their development. In response to this problem and the widespread demands of many parents, in 2021, the Chinese government introduced nationwide regulations limiting the amount of homework teachers can give, as well as when (and for how long) online gaming companies can provide access to young people, and when further education organisations can provide lessons.
A research team of British and Chinese scientists, led by Bai Li of the University of Bristol, assessed the impact of this regulatory intervention on the sedentary lifestyles of Chinese school-aged children and adolescents. To do this, the researchers compared physical activity measures in comparison groups before the law was introduced and after it was introduced. In an initial longitudinal analysis, the researchers analysed data from 7,054 children and adolescents. The average age was 12.3 years.
Children and adolescents reported a 13.8 per cent reduction in average daily total sedentary time, or an average of 46 minutes. Participants were also less likely to report an increase in time spent doing homework and studying outside of school in Key Stage 2 compared to Key Stage 1. Children also had a 6.4 per cent reduction in average daily time in front of screens, or an average of ten minutes. Participants were also 20 per cent more likely to comply with international recommendations for time in front of screens and 2.79 times more likely to meet regulatory requirements for homework time.
Notably, the introduction of the law had a greater impact on high-risk children - secondary school and urban school students - than on low-risk children - primary school students and students in rural areas.
According to the researchers, the introduction of a regulatory statute was effective in reducing overall sedentary lifestyles and various sedentary behaviours among Chinese school-age children and adolescents. Such laws could potentially become part of national health policies in other countries, along with alcohol and tobacco regulation.