Excessive screen time in children increases cardiometabolic risk

A new study published in the Journal of the American Heart Association found that every additional hour of screen time in children and teens is associated with increased risks of obesity, abnormal lipid profiles, and even an increased likelihood of early signs of cardiovascular disease.

How the study was conducted

• Participants: More than 5,000 children and adolescents aged 6 to 19 years from a large, population-representative survey in the United States.
• What was measured:
  • Time spent in front of TV, computer and smartphone screens (survey of parents and the participants themselves).
  • Metabolic health indicators include body mass index (BMI), fasting glucose, lipid profile, and blood pressure.
  • Cardiac markers using metabolomic analysis revealed a “fingerprint” of 25 metabolites associated with cardiovascular disease risk.

Key findings

1. BMI and obesity: Every hour of screen time per day increased the risk of obesity by 5%.
2. Lipid profile: More screen time was associated with increased “bad” LDL cholesterol and triglycerides and decreased “good” HDL cholesterol.
3. Metabolomic fingerprint: The authors identified a set of blood metabolites that form a “screen” biomarker associated with both childhood and adult cardiovascular disease.
4. Role of sleep: Children with insufficient sleep (less than 8 hours) with the same screen time had 12% more metabolic disturbances, suggesting a mediating role of sleep between screen time and heart health.

Why is this important?

Excessive screen time is not just a threat to vision and psyche. A sedentary lifestyle in children triggers early changes in metabolism that then predict the risk of diabetes and heart disease in adulthood. Early identification of the “screen” metabolomic imprint can help intercept the development of pathologies even at the school stage.

“Short videos and endless gaming may seem like a fun routine, but it leaves a serious mark on children’s bodies, creating reduced insulin sensitivity and an atherogenic lipid profile,” said David Horner, lead author of the study.

The authors highlight key findings and practical implications:

1. Screen time as an independent risk factor
   “Our analysis shows that each additional hour of screen time is directly associated with worse cardiometabolic outcomes in children, regardless of their physical activity or socioeconomic status,” said Dr David Horner, senior author of the study.

2. Sleep as a key moderator
   “We found that poor sleep exacerbated the negative effects of prolonged screen time,” adds co-author Professor Sarah Lawson. “This highlights that healthy lifestyle recommendations for children need to include adequate sleep as well as movement.”

3. Future Metabolomic Screening
   “A distinct metabolomic fingerprint of screen time could become an early biomarker of heart risk in adolescents, allowing clinicians to take preventative measures before signs of disease appear,” concludes Dr. Horner.

Recommendations for parents and doctors

• Limit screen time: no more than 2 hours a day for schoolchildren, according to pediatricians' recommendations.
• Monitor sleep: ensure that your child gets 9–11 hours of sleep for younger students and at least 8 hours for older students.
• Encourage activity: At least 60 minutes of moderate or vigorous physical activity daily.
• Use metabolomic screenings: In the future, blood tests for a “screen” biomarker could be used for early intervention for children with high screen time.

This study highlights that screen time among young people is not only an educational and entertainment factor, but also a direct prognostic marker of childhood and subsequent adult heart health.