Excessive Screen Time May Pose Heart Health Risks for Youth

The American Heart Association

Children and young adults who spend long hours on phones, gaming consoles, or other devices may face higher risks for cardiometabolic diseases such as high blood pressure, high cholesterol, and insulin resistance, according to new research published in the Journal of the American Heart Association.

The study analyzed data from more than 1,000 participants in Denmark, finding that increased recreational screen time was significantly linked to higher cardiometabolic risk. The association was especially strong among youth with shorter sleep duration, suggesting that screen use may harm health partly by displacing sleep.

Researchers created a composite cardiometabolic score based on waist size, blood pressure, cholesterol, triglycerides, and blood sugar. Each additional hour of screen time raised the score by 0.08 standard deviations in 10-year-olds and 0.13 in 18-year-olds. This means children with three extra hours of daily screen use could face a substantially higher risk compared to peers.

Lead author David Horner, M.D., Ph.D., of the University of Copenhagen, said, “Limiting discretionary screen time in childhood and adolescence may protect long-term heart and metabolic health. Our study shows this connection starts early.”

Sleep played a key role. Shorter or later sleep intensified the relationship between screen use and risk. About 12% of the link between screen time and cardiometabolic risk in children was explained by reduced sleep duration.

A machine-learning analysis further revealed a “screen-time fingerprint” in blood metabolite patterns, suggesting biological pathways that could carry early signals of long-term cardiovascular risk.

Amanda Marma Perak, M.D., of Northwestern University, noted that improving sleep habits can help reduce screen time’s impact. “If cutting back on screen use feels difficult, start by moving it earlier in the evening and prioritizing more sleep,” she said. She added that adults play a critical role by modeling healthy habits, setting boundaries around device use, and encouraging kids to find ways to cope with boredom without screens.

As an observational study, the findings show associations rather than causation. Still, researchers stress that screen habits should be part of pediatric lifestyle counseling alongside diet and physical activity.