Associate Health Minister Peter Dunne's argument that the Government is focused on activity rather than nutrition when it comes to fighting obesity shows a lack of understanding of the issue, Labour says.

Mr Dunne's statement followed a claim by Fight the Obesity Epidemic spokeswoman Dr Robyn Toomath that the Government had barely acknowledged the obesity issue.

"It must be a prejudicial view that you have brought it on yourself, and that's a nonsense," Dr Toomath said in The Press today.

Stomach-stapling surgery was the only proven treatment and it was "astonishing" it was not publicly funded.

Mr Dunne responded that the Government took obesity seriously and was doing such things as spending about $70 million a year on nutrition and physical activity programmes.

"The previous government focused on nutrition, but we are taking a more balanced approach with a greater role for physical activity and sports programmes in curbing the obesity problem," he told the newspaper.

Labour MP Ruth Dyson today said Mr Dunne's statement showed just how little understanding of the issue there was.

"Recent studies lend further weight to good nutrition in childhood being the more important factor when it comes to tackling obesity," she said.

"Money has been repeatedly stripped out of budgets that had been put in place to tackle obesity. It seems that the National Government is happy for this country to be labelled the third fattest in the world."

Ms Dyson accused the Government of ignoring the problem and said its "so-called sport activity programmes" were having little impact.

"New Zealanders have access to good food and great places to engage in physical activity, but unless the Government plays a leadership role in tacking obesity then we are dooming a generation of young people to suffer with obesity related problems," she said.