Teens who spend too much time in front of a screen may be at risk of poor bone health, including low bone density. A new study from Norway has shown that teens who sit in front of a screen for an extended period of time can develop osteoporosis.

The study involved 484 boys and 463 girls, ages 15 to 18.  The participants underwent bone mineral density tests. During the study, they were asked about their lifestyle habits, such as the amount of time they spent watching TV or on the computer on weekends. Participants were also asked about their levels of physical activity.

Study results indicated that boys spent more time in front of screens than girls did. As the amount of time the boys spent in front of a screen increased, so did their risk of suffering from lower bone mineral density throughout their body.

The study found that girls who spent four to six hours in front of a screen had higher bone mineral density than boys who had just 1.5 hours of screen time a day or less. The difference in bone mineral density between the girls and boys in the study, despite the lower hours the boys spent in front of a screen, could not be explained by other lifestyle factors, which were factored out for the study.

Results from the study were presented at the World Congress of Osteoporosis, Osteoarthritis, and Musculoskeletal Diseases on April 4, 2014.

Participants were involved in a ‘Fit Futures’ study from 2010 to 2011, which assessed over 90 percent of first year high school students within the TromsØ region of Norway.

For the assessment, bone mineral density, or BMD, for every participant was measured at the hip and femoral neck. Additionally, the total body mass index, or BMI, was also measured. For both boys and girls, more sedentary time equaled a lower BMD and higher BMI.

The study results are crucial for younger individuals, whose skeleton fully matures during the teen years, with peak bone mass, or a person’s maximum strength and size, reached by early adulthood.