HMN 2026: How Screen time, BMI, and mental health may be linked to sleep quality in Chinese adolescents

A teen’s mental health, as well as their body mass index (BMI) and screen time, is significantly associated with sleep quality, according to a new paper published in PLOS One by Jianying Li of Shanxi University in China and colleagues. The study also found that girls and adolescents living in more rural areas tend to have lower sleep quality.

Sleep quality is increasingly recognized as a critical lifestyle determinant of physical and mental health during adolescence, yet declining sleep quality among adolescents has become a growing public health concern. Factors such as screen use, sedentary behavior and mental health problems have been linked to poor sleep in young people, but there have been few systematic evaluations of how these factors interact with residential location and gender.

In China, specifically, improving sleep quality and mental health has become a mainstream focus of the government, with programs like Healthy China 2030 prioritizing sleep duration and the National Health Commission designating 2025–2027 as Years of Pediatric and Mental Health Services.

In the new study, researchers surveyed 5,713 adolescents ages 13 to 18 across six cities in China: Shanghai, Suzhou, Taiyuan, Wuyuan, Xingyi and Urumqi. They collected data on sleep quality using the Pittsburgh Sleep Quality Index (PSQI), as well as data on BMI, physical fitness, sedentary time, screen time and mental health. Data were also available on each participant’s residential location (urban or rural) and gender.

Overall, 33.71% of participants had poor sleep quality. Mental health emerged as the strongest protective factor, with higher mental health scores associated with lower risk of poor outcomes across all sleep measures. Higher BMI, more sedentary time and more screen time were associated with greater odds of poor sleep outcomes.

The researchers also found significant disparities by residence and gender. Rural adolescents had higher rates of poor sleep quality than their urban peers (35.78% vs. 31.90%, p

Rurality and gender also moderated how strongly behavioral and health factors affected sleep: the adverse effects of higher BMI on sleep were more pronounced in girls, while the protective effects of good mental health were stronger among rural adolescents.

The study is limited by its cross-sectional design, which does not allow causal conclusions. Sleep quality and behavioral indicators were assessed by self-report, which could have introduced bias, and nuances in the daily timing of sleep, screen time and sedentary time were not available.

The researchers conclude that Chinese adolescents living in rural areas and female adolescents may experience a greater burden of poor sleep quality, and that addressing screen time, BMI and mental health might be key to improving sleep across the adolescent population.

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