The longer young children watch television, the less they sleep. US researchers discovered this small yet consistent association in a long-term study, the results of which were published in "Pediatrics".
Scientists at Harvard University (Boston) followed 1,800 children aged between six months and nearly eight years who participated in Project Viva, a long-term study on health effects of several factors during pregnancy and after birth. The mothers regularly reported on the sleep duration of their children, how much time they watched television daily or were in a room where a television was switched on, and whether they slept in a room with a TV.
According to the data, each additional hour of television viewing led to seven minutes less sleep daily, whereby this association was stronger in boys than in girls. It was also noteworthy that ethnic minority children were more likely to sleep in a room with a television. Children who had a TV in their bedroom had half an hour less sleep per day.
Thereby, the researchers were able to confirm earlier short-term studies, which had shown that television viewing and sleeping in a room with a television reduces sleep time, which can have a negative effect on mental and physical health in children.