Tue Apr 15, 2014 1:20PM

In the first long-term study of its kind, US researchers have confirmed findings of previous, shorter studies that show the more time infants and young children spend in front of the TV the less time they spend asleep.

Researchers from Massachusetts General Hospital for Children and Harvard School of Public Health also found that, particularly among minority children, having a TV in the bedroom is also linked to shorter sleep time, according to medicalnewstoday.com.

The team followed more than 1,800 children aged between 6 months and nearly 8 years, who were enrolled with their mothers in a long-term research program called Project Viva, which is investigating numerous factors linked to children's health, starting from before birth.

To provide the data for the study, the children's mothers answered questions when the children were around 6 months old, and then every year for another 7 years.

The mothers gave information about their children's TV viewing habits, such as whether they had a TV in their bedroom, how much time they spent in a room where the TV was switched on when they were babies, and how much TV they watched when they were older.

The mothers were also asked to say how much time on average their children slept every day.

When they analyzed the results, the researchers found a small but consistent link between longer TV time and shorter sleep time.

Over the period of the study, every extra hour of TV viewing time was associated with 7 fewer minutes of daily sleep time, and the link was stronger for boys than for girls.