Paula Bennett opens up about gastric bypass weight loss

National MP Paula Bennett has opened up with a "personal post" on Facebook to mark one year since her gastric bypass, calling it the "hardest thing physically," she's ever done. 

Bennett posted on her personal Facebook page on Sunday night, to reflect on the "journey" of losing 50kg within 12 months. 

"My weight has never defined who I am and it still doesn't", Bennett wrote. "My body is simply the vessel that carries me around and currently it is smaller." 

A gastric bypass shrinks the size of the stomach, making patients feel full quicker so they eat less. The surgery is publicly funded for eligible patients, but Ms Bennett paid for hers out of her own pocket at a private clinic.

In her post, Bennett also said she wanted to answer some of the "most asked questions" that revolve around her health. 

"Yes I eat differently and much less (was kinda the purpose of the op)," she pointed out. 

"Yes I can drink wine (and eat chocolate and pies) - No I don't have huge amounts of extra skin.  

"No I don't know what you should do, it's very personal. Yes, I know I am over sharing!" 

She finished the post by thanking her followers "for their really kind and positive words over the past year". 

Bennett may be celebrating the year with a new wardrobe, after telling the AM Show in April she kept throwing clothes out, but not buying many new ones. 

"They say 'don't do that until you get to your target weight'," she revealed