What's in a Kiwi kid's bedroom? Television

Nearly half of 9- to 15-year-olds have their own television sets, prompting concerns that we could grow into a "nation of teletubbies".

A review of the studies on childhood obesity and television watching habits has found strong links between the two - but the cause was more likely to be the unhealthy food eaten by children watching TV rather than a decline in physical activity.

Among research papers the review covered was the 2005 Census At School conducted by the Auckland University, which found 48 per cent of Year 5 to 10s have their own televisions.

The average New Zealand child watches more than two hours of television daily and approximately three out of every four food advertisements promote foods "counter to improved nutrition".

The report, commissioned by health advocates Agencies for Nutrition Action, will be released tomorrow at the Public Health Association conference in Palmerston North.

Co-author Dr Robert Scragg from Auckland University's school of population health said the report conclusively found that watching television contributed to obesity in children.

Public health specialist Robert Quigley, who co-wrote the report, said this was probably related to the increased exposure to advertising of foods high in fat and sugar.

"Unless we find ways to ensure children watch less TV, or make TV safer by getting rid of the food advertising, we'll end up with a nation of teletubbies."

There are few restrictions on advertising unhealthy foods to children, and this should change, said Mr Quigley. Sweden and Norway ban marketing to children under 12.

However, Advertisers Association executive director Jeremy Irwin said people need only look at Sweden's and Norway's obesity rates.

"They've gone up, like any other country. It's a very good example where advertising is absolutely no cause because there isn't any."