Former Maori Party co-leader Dame Tariana Turia says her gastric bypass operation changed her life.
Deputy National Party leader Paula Bennett is the latest in a long line of politicians to undergo gastric bypass surgery.
Just 400 people had the operation under the public health system last year, and Dame Turia believes the Government should be funding more.
"My health improved dramatically very quickly," she said.
"It was a very positive experience for me and it continues to be.
"People have been on the waiting list since day dot, and I think it's incredibly unfair that people who don't have the means for that operation should have to wait or to go without.
She said it was an "indictment of the protection of fat people" in a way.
"Everybody thinks it's your own fault so they don't see why you should be able to have a publicly-funded procedure, but they don't think twice if someone goes out and drinks and has an accident."
It wasn't until Dame Turia started getting unwell that she decided she needed to do something about it.
"It was very clear that diet didn't work for me so I went along and saw [doctor] Richard Stubbs and the rest is history.
She said Parliament was a very unhealthy environment to be in every day.
"It's very taxing, you find yourself picking and eating what you shouldn't eat."
While many have called the surgery a shortcut, Prime Minister Jacinda Ardern on Monday told The AM Show she would never describe the operation as "cheating".
"This surgery does have the ability to save taxpayers in the long-term if it's solving something like Type 2 diabetes.
"But we've got to make sure those who are accessing it are the most likely to achieve success from it as well."