The glow of a television or a computer is robbing children of sleep and potentially contributing to poor lifestyle habits and obesity.
A Canadian study adds to the growing body of evidence that children's sleep patterns are being adversely impacted by technology.
The University of Alberta research surveyed 3,400 grade five students and found that half of them had a television, DVD player or video game console in their room.
Twenty-one per cent had a computer and 17 per cent had a mobile phone. Five per cent had all three types of devices.
Almost 60 per cent of students used the devices after they were supposed to be asleep, with most watching TV and movies. Children with one or more of these devices in their bedrooms were more likely to be overweight or obese.
Kids with one electronic device were 1.5 times as likely to be overweight as children with no devices in the bedroom. That increased to 2.6 times for kids with three devices, with similar results reported among obese children.
But getting even one hour of additional sleep a night decreased the odds of being overweight or obese by 28 and 30 per cent, respectively.
"If you want your kids to sleep better and live a healthier lifestyle, get the technology out of the bedroom," said co-author Professor Paul Veugelers.