It's just over a year since Maori Party co-leader Tariana Turia had her stomach-stapling operation. Since then, she's lost 32kg and picked up a few new hobbies.

There is fishing, and hurtling along the sidelines of the sportsfield cheering on Piata, the granddaughter she is raising.

Mrs Turia hasn't quite gone through the dramatic metamorphosis of others who have had the same operation, such as former Act MP Donna Awatere Huata, who went from a battleship to a Barbie doll.

She is nonetheless a much smaller version of the old Tariana. She says it is not as much weight as she could have lost and admits, with very little penitence, she doesn't always stick to her doctor's orders.

Her main focus is on feeling well rather than looking good - in fact, she is wary of losing too much weight.

Before the operation, she confessed, she was concerned she would end up looking like a goblin after seeing the effect of dramatic weight loss on others.

The Prime Minister had told her at the time that she would look like a pixie. Mrs Turia laughs when reminded of this.

"He hasn't called me pixie lately, I've noticed. I'm quite offended by that, so obviously I haven't quite got to the pixie stage. But I was worried. I saw some people who got so tiny you didn't know it was the same person. I didn't want to be doing that.

"I have no intention of looking like Twiggy. I'm actually very satisfied with where I've got to. I don't follow religiously what the doctor has asked me to do because I think I would have lost a considerable amount more. And I don't really want to lose too much, so I do eat a little bit more than what they tell you you can."

Mrs Turia's life, nonetheless, has changed significantly. "I can walk further. I can run up and down when my baby [Piata] is on the sportsfield."

Mrs Turia claims she doesn't yell at the ref - "I'm too busy telling my baby to 'go harder'. I'm just pleased I've got so much more energy to do things with her.

"In the past, I was always tired. What used to really upset me the most was that my little one would say to me in the evening or at weekends, 'Mama, can we go to the park?' and I'd say, 'Oh, Mama's too tired.'

"There's no excuse for that now. I can go, and she expects me to. I don't think she'd accept it if I said I was too tired."

Mrs Turia's wardrobe hasn't quite caught up with her weight loss yet. She remains wary of anything other than baggy clothing.

"I can't see me getting into the slinky stuff. Already I have relatives asking why I still wear my big tops and skirts. It's because I'm most comfortable doing that. I'm kind of not into the 'glammy'. Never have been. It's just not me."

For a public figure, she is also shy about the attention it gets her, with people standing at public meetings to say how well she looks.

The feedback isn't always good. Mrs Turia says she's received abusive letters from people who say she's "still fat" or that "fat people should just stop eating rubbish" and criticising her for being able to pay for the surgery herself.

She is in awe of people who lose significant amounts of weight through diet and exercise.

"I know what a struggle it is to do it. I was never going to be saying to people, 'You're too fat because you eat all the wrong things', because I've been there and done that and I know how hard it is."

But having experienced the change the operation made in herself - getting rid of the diabetes and illnesses that came with it - she has also lobbied hard to secure more operations for those who can't afford the $17,000 to $35,000 themselves.

As Associate Health Minister, she twisted Tony Ryall's arm to secure a 25 per cent increase in the number of bariatric surgery operations offered in the public health system - about an extra 75 operations a year.

Mrs Turia says she misses rice, pastas with sauces, and fatty meats - "that was a great love, unfortunately ... I'm still very engaged with kai though. If I smell kai, I'm still attracted to all the foods I'd had in the past that I so loved." But fish remains on the menu.