Healthcare lobbyists have criticised the Government's funding cuts in the face of a report showing New Zealand is the third fattest nation in the developed world.

They fear disease and complications caused by obesity will lead to higher healthcare costs in the future.

The Health Care Data 2009 report, by the Organisation for Economic Co-operation and Development, focused on 30 nations.

Of those that reported on weight issues, all showed they were getting fatter.

The obesity rate among adults in New Zealand in 2007 was 26.5 per cent. This compared with figures reported the previous year by the United States at 34.3 per cent and Mexico at 30 per cent.

The figure compares with a reported 25 per cent obesity rate in New Zealand in 2003 and 18 per cent in 1997.

"Given the time lag between the onset of obesity and related health problems (such as diabetes, cardiovascular diseases and asthma), the growing prevalence of obesity in most OECD countries, including New Zealand, may well lead to higher healthcare costs in the future," the report said.

Budget documents released last month said $37 million had been docked from 18 health promotion services, including $2.3 million from cancer control, $4.8 million from the "let's get checked" diabetes programme and $3 million from the heart disease budget.

Since it was elected in November, National has cut funding to several anti-obesity campaigns, including Labour's curbing of fatty foods in school tuckshops.

The executive director of the Obesity Action Coalition, Leigh Sturgiss, said there needed to be a campaign tackling obesity similar to those used to battle smoking.

It would include a public awareness campaign, increasing taxes on sugary drinks and banning television advertising of unhealthy foods until at least 8.30pm.

"We're eating far too much of the wrong food," Ms Sturgiss said. "It's accessible, it's cheap, we see it advertised on TV, we're busy, sometimes the choice isn't there. There are parents trying to operate on reduced incomes because they've lost jobs or sometimes these parents are working two jobs each and are unable to monitor what their kids are eating during the day.

"Kids are sitting in front of the TV for far longer rather than participating in organised sport or just being outside playing."

Ms Sturgiss said she was waiting for a policy announcement from the Government on how it intended to combat obesity. "Before they were elected John Key indicated he considered the answer to be bats and balls in schools. We don't agree with that. There's just a policy vacuum from within the minister's office with regards to what we're actually supposed to do. I appreciate they're running around with this swine flu stuff ... but they got elected in November and it's not midway through July. We've been told things have been cut ... but what are they going to do?"