Summary: A global study reveals adolescents spend 8-10 hours daily on sedentary activities, far exceeding the World Health Organization’s 2-3 hour recommendation. Social media accounts are significantly linked to increased screen time and overall sedentary behavior, raising concerns about its impact on physical health.
Adolescents in walkable, safer neighborhoods reported less screen time and higher physical activity, with girls benefiting more from activity-friendly designs. These findings emphasize the need for parents, policymakers, and tech companies to collaborate on strategies to reduce screen time and encourage active lifestyles for youth.
Key Facts:
- Adolescents globally exceed recommended sedentary time by 5-8 hours daily.
- Social media access correlates with increased screen time and sedentary behavior.
- Walkable neighborhoods and safety perceptions reduce recreational screen time.
Source: UCSD
The World Health Organization recommends no more than two to three hours per day of sedentary time for youth. However, adolescents worldwide are spending an average of 8 to 10 hours per day engaging in sedentary activities such as watching television, using electronic devices, playing video games and riding in motorized vehicles, according to a multinational study published in the Nov. 29, 2024 issue of the International Journal of Behavioral Nutrition and Physical Activity.
The most notable finding of the study, led by principal investigator James F. Sallis, Ph.D., distinguished professor at the Herbert Wertheim School of Public Health and Human Longevity Science at University of California San Diego, and colleagues from 14 countries, found that simply having a personal social media account was linked with higher total sedentary time in both males and females. Social media was also related to more self-reported screen time.
“Although there is great concern about negative effects of social media on youth mental health, this study documents a pathway for social media to harm physical health as well,” said Sallis, who is also a professorial fellow at the Australian Catholic University.
“These findings are concerning, as excessive sedentary behavior has been linked to a range of health problems, including obesity, diabetes and mental health issues.”
Researchers analyzed accelerometer data from 3,982 adolescents aged 11 to 19 and survey measures of sedentary behavior from 6,302 participants in the International Physical Activity and the Environment Network (IPEN) Adolescent Study, which covered 15 geographically and culturally diverse countries across six continents.
The number of electronic devices within a home, how many adolescents had their own social media accounts and neighborhood walkability were significantly different across countries.
For example, adolescents from India had an average of 1.2 electronic devices in the bedroom and 0.5 personal electronic devices, while the average number of such devices in Denmark was 4.2 and 2.3, respectively. In India and Bangladesh, fewer than 30% of adolescents reported having their own social media account, compared to higher socio-economic status countries where it was over 90%.
Parents reporting on walkability identified Australia as having high access to parks, while Nigerian parents reported no access, and parents in Bangladesh and India reported poor access. Traffic was a concern among parents in Brazil, Malaysia, Bangladesh, India, and Israel, and concerns about crime were high in the first three countries.
Adolescents who reported less recreational screen time lived in walkable neighborhoods and had better perceptions of safety from traffic and crime than others. Girls who lived in neighborhoods designed to support physical activity were less likely to be sedentary.
Despite differences in culture, built environments and extent of sedentary time, patterns of association were generally similar across countries, said the study’s lead author Ranjit Mohan Anjana, M.D., Ph.D., of Dr. Mohan’s Diabetes Specialties Centre and Madras Diabetes Research Foundation in India.
“Together, parents, policymakers and technology companies can work together to reduce access to screens, limit social media engagement and promote more physical activity, thus helping adolescents develop healthier habits and reduce their risk of chronic diseases,” said Anjana.
The study’s findings have significant implications for public health policy and highlight the need for further research into the causes and consequences of sedentary behavior among teenagers.
Countries involved in study: Australia, Bangladesh, Belgium, Brazil, China, Czechia, Denmark, India, Israel, Malaysia, Nigeria, Portugal, Spain and United States.
Funding: This research was funded, in part, by the National Institutes of Health (R01 HL111378, R01 HL083454).
About this neurodevelopment research news
Author: Yadira Galindo
Source: UCSD
Contact: Yadira Galindo – UCSD
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Associations of perceived neighbourhood and home environments with sedentary behaviour among adolescents in 14 countries: the IPEN adolescent cross sectional observational study” by James F. Sallis et al. International Journal of Behavioral Nutrition and Physical Activity
Abstract
Associations of perceived neighbourhood and home environments with sedentary behaviour among adolescents in 14 countries: the IPEN adolescent cross sectional observational study
Background
Understanding environmental correlates of sedentary behaviour (SB) among young people is important as such data can identify approaches to limit sedentary time. This paper estimates associations of parent-reported neighbourhood and adolescent-reported home environments with SB among adolescents aged 11–19 years from 14 countries.
Methods
In the International Physical activity and the Environment Network (IPEN) Adolescent Study (an observational, cross-sectional multi-country study), adolescents wore a triaxial accelerometer for seven days that assessed sedentary time (ST). Adolescents completed survey measures of sedentary behaviour (SB) related to recreational screen time and sitting time in motor vehicles.
Parents and adolescents completed surveys assessing neighbourhood and home environments. Accelerometer based ST was available in 3,982 adolescents while survey data were available for 6,302 dyads. We estimated the total and direct effects of each environmental attribute on ST and SB. Sex of the adolescent and city/country were examined as moderators.
Results
The average ST in adolescents from 14 countries ranged from 7.8 to 10.5 h/day. Personal social media was the only significant correlate of total ST across both sexes. With respect to self-reported SB, adolescents accumulated an average of 3.8 h of non-school screen time per day and nearly 40 min of transport-related sitting time.
Screen time was associated with all home environment variables, including social media account, as well as land use mix—diversity, traffic safety, and crime safety.
Transport-related sitting time was related to land use mix—diversity, recreation facilities, walking facilities, and pedestrian infrastructure, but no home environment variables. City/country and sex were significant moderators of several associations.
Conclusions
Both home and neighbourhood environment features were related to ST and SB. Having social media accounts emerged as a major contributor towards sedentarism in adolescents.
