The World Health Organisation has suggested that a complete ban on advertising junk food to children is preferable to more limited controls such as those used in New Zealand.

A paper to be considered this month in Switzerland by the WHO's executive board, on which New Zealand holds a seat, recommends the aim should be to reduce the marketing to children of foods high in bad fats, sugar or salt.

It notes that countries can adopt a "comprehensive approach" which fully eliminates all marketing of unhealthy food and drink to children, including the newer channels like websites, emails and text messages - or they can take smaller steps.

"A comprehensive approach has the highest potential to achieve the desired impact," the paper says.

Food and advertising interests in New Zealand have objected to aspects of the paper by WHO officials, but a leading public health campaigner, Emeritus Professor Robert Beaglehole, of Auckland University, says the time has come to impose a complete ban.

He said New Zealand's system of self-regulation of food marketing by the food and advertising industries did too little to protect children from the risks of becoming obese.

Nearly a third of children and two-thirds of adults are overweight or obese.

"It's very important that we do everything we can to protect children from commercial influences," said Professor Beaglehole, a former director of the WHO's department of chronic diseases and health promotion.

But the Association of New Zealand Advertisers' executive director, Jeremy Irwin, said yesterday that self-regulation - under codes overseen by the Advertising Standards Authority - was working well and no further regulation was required.

"The work that has already been done by [the association] and the Food Industry Group covers many of the aspects that the WHO is proposing."

The codes on advertising food and advertising to children were being reviewed and an additional code, on advertising food to children, which would cover concerns about foods high in fat, sugar or salt, was about to be released, he said.

Television stations in 2008 agreed to make food advertising during school-aged children's programming times reflect the Government's Healthy Eating-Healthy Action policies. Advertising during pre-school programming times is not permitted.

But public health lobbyists complain many children are exposed to ads for unhealthy foods and drinks because they commonly watch TV outside the so-called "children's" hours.

Health Minister Tony Ryall said the Government was "reasonably comfortable with the options set out in the paper".

However, it had no intention of banning the marketing of food and drink to children, but nor would there be any weakening of the regime.

"We are very keen to maintain the self-regulatory approach. That's dependent on the industry continuing to be responsible and involved and engaged.

"I think there are some options the industry could work on to improve the situation," he said. "What we will do is wait and see what comes out of the review, then continue our discussion with the industry."