Australian kids seem to stay slim and active if they go to bed early and get up early. Late risers, on the other hand, were 1.5 times more likely to become obese, almost twice as likely to be physically inactive, and 2.9 times more likely to sit in front of a screen – computer or TV – for more hours than the early birds.
Researchers at the University of South Australia looked at the hours sleeping, bedtimes and wake times of 2,200 youngsters ages 9 to 16 as well as at their weight and how they spent their time over four days. Earlier research suggests that not getting enough sleep puts kids at risk of becoming overweight or obese, but this study found that all the kids averaged the same number of hours of sleep.
The differences in weight and amount of physical activity seen related to the timing of their sleep, and that timing was not dramatic: the night owls stayed up 70 to 90 minutes later than the early birds and woke up 60 to 80 minutes later. The study was published in the Oct. 1 issue of SLEEP.