WHO says kids under two shouldn't have any screen time at all

Preschool kids shouldn't be in front of screens for more than an hour a day, while toddlers and babies shouldn't at all, according to new recommendations.

Letting them play computer games and watch too much TV or YouTube will increase the chance they grow up sedentary and obese, the World Health Organization (WHO) says.

"Early childhood is a period of rapid development and a time when family lifestyle patterns can be adapted to boost health gains," said WHO director-general Tedros Adhanom Ghebreyesus.

It's the first time the WHO has issued guidelines on childhood activity. They include no screen time for kids two and under, and under an hour for kids aged three or four.

Once they're walking, children should have "at least" three hours of physical activity every day, the guidelines say. No children under five should spend more than an hour restrained (eg. in a high chair, pram, bouncer or to a caregiver), and babies should have at least half-an-hour on their tummies.

Newborns should have at least 14 hours' sleep a day, toddlers 11 hours minimum and older pre-schoolers, 10.

"What we really need to do is bring back play for children," said WHO doctor Juana Willumsen. "This is about making the shift from sedentary time to playtime, while protecting sleep."

Screen time, particularly before bedtime, has been linked to worse sleep. Like the WHO, the New Zealand Ministry of Health recommends no screen time at all for kids two and under, and less than an hour each day for kids between two and five.

"While some screen time can be beneficial for learning, that time needs to be balanced with regular physical activity and outside play, which we know are key to children's development," Social Development Minister Carmel Sepuloni said in January, when a local study was published linking excessive screen time with obesity and hyperactivity.

Recent studies on children older than five, and teenagers, have found little evidence of detrimental effects.

The WHO says its report, published Friday (NZ time) is intended to help local authorities to develop their own plans.