Is screen time affecting boys’ bones?

Teen screen time is an inevitable part of life. Schools are increasingly requiring more online research for homework assignments. And when kids get home, they may indulge in video games, watching TV or spending time on social media catching up with friends.

Now, a new study from Norway finds that all that sitting around isn’t just increasing waistlines; it’s detrimental to teenage bone health.

The data was gathered from 463 teen girls and about 483 teen boys. The boys, age 15 to 18, reported high amounts of screen time and when tested, their bone mineral density levels were far below those of their male counterparts who spent less time online and who were more physically active.

Surprisingly, the study also showed that in girls, those with higher screen time had higher bone density. These results were intriguing to the researchers and need further study.

The results of this study regarding boys, however, “clearly show that sedentary lifestyle during adolescence can impact on [bone mineral density] and thus compromise the acquisition of peak bone mass,” says lead author of the research, Dr. Anne Winther, in a statement.

Bones grow from infancy to early adulthood with the majority of size and strength growing during the teenage years. The study shows the importance of physical activity as well as nutrition during these critical years of skeletal growth, researchers said.

Health experts say that children should exercise at least one hour a day and include weight-bearing exercises to help strengthen the skeleton from different angles.

Christine Cornell, group fitness coordinator at Advocate Good Samaritan Health and Wellness Center in Downers Grove, Ill., agrees.

“It’s important to build strong bones during youth because you build the majority of your bone by your early 20s,” she says. “We can prevent osteoporosis in older age by increasing the amount of high intensity training during youth as well as variety in forms of exercise.”