Children who sleep more appear to eat less, reducing their risk of becoming overweight or obese, a new study indicates.

According to US scientists, this is the first known study to investigate the impact of sleep on the way children eat, by manipulating the amount of sleep they were able to get.

The study followed the progress of 37 children aged eight to 11. Just over one in four of these was overweight or obese.

For one week, the children slept their normal amount. However, during the second week, the group was randomly split up, with one group getting reduced sleep and the other group getting even more sleep than usual.

The scientists found that during the second week, the children who had slept for longer had consumed an average of 134 fewer calories per day. By the end of the week, they weighed a half a pound less and they had lower levels of the hormone, leptin, in their body. Leptin has a key role in regulating hunger.

"The findings from this study suggest that enhancing school-age children's sleep at night could have important implications for prevention and treatment of obesity. The potential role of sleep should be further explored," the scientists explained.

They added that given all its known benefits, ‘you can't lose in promoting a good night's sleep'.

Details of these findings are published in the journal, Pediatrics.