WASHINGTON: Children who are allowed to go out unsupervised grow up to be healthier and more sociable, according to a new study.

The study, led by Professor Roger Mackett of the Department of Civil, Environmental and Geomatic Engineering at the University College London, found that kids who are permitted to leave the house without an adult supervision are more active and enjoy a richer social life than those who are constantly supervised.

For the study, the team studied 330 pupils from two schools in Cheshunt, Hertfordshire, all aged between 8 and 11. The children completed questionnaires, kept travel diaries, had their movements logged using GPS monitors and wore portable motion sensors to measure their speed of travel, changes in direction and the number of 'activity calories' they consumed.

"We asked children whether they were allowed out without an adult and then looked at where they go and how they behave. In general, children who aren't constantly supervised tend to leave the house more often - exploring their surroundings, playing with other children and using up more calories than their sedentary, house-bound peers," Prof Mackett said.

They found that children allowed out without adults were more active and burnt more calories than their constantly supervised peers.

The study also showed that children walk faster and take a more direct route when an adult is present, but they do not use more energy than unaccompanied children. This is because unsupervised children move in a more meandering fashion as they investigate their environment and socialise with other children.

The results indicated that access to local open space is a noteworthy factor in determining whether boys are allowed out of the house without an adult. 71 percent of those with access to open space were allowed out, compared to just 51 percent of those without such access.

The team also found that of the three types of activity monitored during the study (walking, unstructured play and participation in organised clubs), walking used up the most activity calories.

"Fears over road safety and 'stranger danger' need to be balanced against soaring levels of childhood obesity and poor health. Letting a child out to play is one of the best things a parent can do for their child's physical health and personal development," Prof Mackett said.

"Allowing children to leave the house without an accompanying adult has significant benefits, but we need to design and build environments that children feel comfortable in and that parents feel confident to let them use on their own. The health benefits are clear, but without action the less tangible benefits of increased independence, self-reliance and general 'growing up' are in danger of being lost," he added.