Updated 1.17pm: New Zealand needs to offer publicly funded stomach stapling, as it faces an obesity epidemic.

Christchurch bariatric surgeon Steven Kelly believes that in five years, we could have become the world's fattest nation.

He's urging the Government to increase the number of publicly funded stomach stapling procedures to combat the issue.

But Health Minister Jonathan Coleman says surgeries won't fix the obesity problem.

"I'm really interested in long term solutions to the problem, especially focusing on kids and preventing them from becoming overweight in the first place, because that is where the pattern is set for the rest of their lives."

Jonathan Coleman says claims the surgeries would save them money aren't true.

He says the reality is the surgeries will become a short term solution.

Steven Kelly told Newstalk ZB's Mike Hosking diet and exercise doesn't work for most morbidly obese people.

"If somebody's morbidly obese at 150kg, they can't afford just to lose three or four kilos. To make a big difference to their lives they really need to lose 50 kilos and the only way they can realistically do that long term is with surgery."

Mr Kelly says we need to follow other countries and offer this surgery to far more people.

"Compare it to the alternatives which are dieting and exercise and drugs. We know they don't work. The only thing that works with significant weight loss for the morbidly obese is weight loss surgery."