According to the researchers, teens’ excessive screen time is associated with adopting more sedentary lifestyles and getting less sleep. Their work also revealed that a large number of teens are on multiple screens at the same time, and this habit is particularly concerning when looking at overall health and wellness.
“Sadly, this study reminds us that we are in danger of creating a new generation of sedentary children,” said researcher Melanie Davies. “Increased sedentary time is closely linked to type 2 diabetes, which is increasing in younger age groups. The number of young people with type 2 diabetes has gone up by 50 percent in just five years.”
Excessive screen time risks
For the study, the researchers analyzed data from more than 800 girls between the ages of 11 and 14 who were enrolled in the National Institute for Public Health Research (NIHR) program. The participants wore devices on their wrists that tracked their physical activity and sleep throughout the study, and then they answered questions about their typical screen time use and general mental health.
The researchers learned that the participants that spent the most time in front of screens had the lowest physical activity levels over the course of the study, which also correlated to higher body mass indices (BMI). The study also showed that participants’ sleep was disrupted by screen time, particularly when they used smartphones after school.
“Intuitively, we believe there must be negative effects on teenagers of using too many screens at the same time,” said researcher Dr. Deirdre Harrington. “Our data shows it isn’t as simple as that.”
Using multiple devices at once
Perhaps the biggest takeaway from the study was that a large number of the participants reported using multiple devices at the same time, with teens using as many as four different devices simultaneously. Nearly 70 percent of the participants reported using more than one device at the same time on the weekends, while nearly 60 percent of the participants were using multiple devices after school. These habits also correlated with less physical activity and less sleep.
Moving forward, the researchers hope that more work is done in this area, because the effects of screen time -- especially when more than one device is involved -- are wide-reaching.
“This research was done before the COVID-19 lockdown, where much more of our day is spent in front of a screen,” Dr. Harrington said. “More than ever the effects of this on adolescents needs to be known -- there are positives too, no doubt.”