London, Sept 30 : Benjamin Franklin quoted three centuries ago that `early to bed, early to rise keeps a man healthy, wealthy and wise'.

Now a new study has confirmed it - it found that sending children to bed early and waking them early keeps them slimmer and physical active than their night-owl peers.

Researchers at the University of South Australia recorded the bed and wake times of 2,200 participants, aged 9 to 16, and compared their weights and uses of free time over four days.

The average early bedtime was 9.20pm while early wakeups were 7am.

Late bed times were around 10.40pm and late wake-ups 8.20am.

They found that children who went to bed late and got up late were 1.5 times more likely to become obese than those who went to bed early and got up early.

In addition, night-owl children were almost twice as likely to be physically inactive and 2.9 times more likely to sit in front of the TV and computer or play video games for more hours than guidelines recommend.

"The children who went to bed late and woke up late and the children who went to bed early and woke up early got virtually the same amount of sleep in total," the Daily Express quoted study co-author Dr Carol Maher, as saying.

"Scientists have realised in recent years that children who get less sleep tend to do worse on a variety of health outcomes," she said.

"Our study suggests that the timing of sleep is even more important," she added.

Maher, however, said more studies were needed to understand why bed and wake-up times had such an effect on children''s health.

The findings are published in the October issue of the journal SLEEP. (ANI)