Teenage boys’ TV viewing a risk to bone health

Teenage boys who spend lots of time in front of the TV or computer screen are at risk of poorer bone health, research has found.

A study carried out in Norway found the same did not apply to girls, which it suggested could be explained by their different body fat distribution.

Researchers looked at how much time 15- to 18-year-olds said they spent sitting in front of screens at the weekend, with between four and six hours being the most common amount of time in the 1,000 students questioned.

This was followed by more than six hours in boys, but between two and four hours in girls.

The school pupils’ bone mineral density was analysed along with their height, weight and details of their lifestyles.

The team found that while girls in the four- to six-hour category had the highest bone mineral density, the amount of time spent in front of screens had a negative effect on the bone mineral density of boys.

“Our study suggests persisting associations of screen-based sedentary activities on bone health in adolescence,” the study authors said.

“This detrimental association should therefore be regarded as of public health importance and followed closely, since improvement of peak bone mass is possible.”

Researchers said that girls tend to perform several activities at once — spending time in front of the TV or computer screen as well as on their phones or carrying out other tasks, such as hobbies or crafts.