Modern children go to bed 40 minutes later than their grandparents did.
Modern day children go to bed 40 minutes later and spend two hours less playing outside, new research shows.
In addition, they also eat later, and these three factors could be having a detrimental affect on their ability to sleep weel, according to The Sleep Council.
The study found that today's seven to 14-year-olds go to bed almost 40 minutes later than their grandparents.
The Sleep Council survey asked 1,006 grandparents with grandchildren aged seven to 14, to compare their early lifestyle with that of their grandchildren.
A fifth of grandparents said when they were children, they would spend more than three hours playing outside on an average school day.
This compares to the 28 per cent who said their grandchildren now spend less than 30 minutes playing outside on an average school day.
When they were children, 24 per cent of grandparents went to bed on a school night between 7 - 7.30pm whereas 20 per cent of children now go to bed between 8.30 and 9pm.
Before bedtime, 54 per cent of grandparents read books when they were schoolchildren, whereas less than a third of today's children read books before bedtime - 58 per cent now spend that time watching television.
In terms of main meals, 70 per cent of grandparents ate dinner before 6pm whereas 38 per cent of children now eat that early. Just over half - 51 per cent - eat between 6pm and 7.30pm.
A third of grandparents had to share a bedroom when they were children whereas almost three quarters of children now have their own bedroom. Of those, 63 per cent have a television in the room.
Jessica Alexander, of The Sleep Council, said: "Modern lifestyles could be having a seriously detrimental effect on children's ability to get a good night's sleep.
"Today's youngsters get a lot less fresh air and exercise than their grandparents did, go to bed later and watch TV rather than read.
''Much more encouraging is the fact that today's youngsters are far more likely to sleep on a new bed and have a room of their own."
Read more at the Telegraph Website.