研究显示:早睡早起的儿童更苗条,更健康,更活泼.

A new study reveals one way to keep your kids leaner: keep them on an early-to-bed, early-to-rise sleep schedule.

The University of South Australian study, published in the journal Sleep, found that early-rising kids were slimmer and more physically active than their night-owl counterparts, even though both groups got the same amount of sleep.

The study -- which involved 2,200 kids ages 9 to 16 -- found that those kids who went to bed late and slept in were 1.5 times more likely to become obese than the early risers. In addition, late-nighters were almost twice as likely to be physically inactive and 2.9 times more likely to spend too much time in front of the television or playing computer or video games, the researchers said.

Co-author Dr. Carol Maher suggested that one explanation is that mornings are more conducive to physical activity for young people than nights, which offer prime-time TV programming and social networking opportunities.

For the grownups, research also finds that going to bed early and rising early not only keeps you leaner but also improves your performance in the workplace and boosts your mood.

"Morning people tend to be healthier and happier as well as having lower body mass indices," researcher Dr. Joerg Huber of Roehampton University in London said in a British Psychological Society conference, according to the Telegraph earlier this month.

Want to keep your kids active and fit? Keep them on an early-to-bed, early-to-rise sleep schedule.