Looks like Chris Noth is no longer Mr. Big.

The Sex and the City star, 54, opens up to Usmagazine.com about slimming down before reprising his role in the sequel (due March 2010).

"I went to a place called the Island Experience in Brazil on Ilha Grande. It's two hours drive from Rio and 40 minutes by boat," he told Us at the Oral B Pulsonic showcase in NYC Sunday. 

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"Usually it's about going to a trainer and all that but [the resort has] a very holistic approach. But I needed to bring my body into fitness -- so I went for nine days," he says. "It was a total vegetarian diet. Basically, you spend all day doing yoga, hiking, kayaking, eating vegetarian food, no coffee, no alcohol, no meat. 

"You're cleansing yourself, but not starving yourself," he goes on. "I've never been a vegetarian, but the way they prepare it is exquisite. And you're in one of the most beautiful Atlantic rain forests on the planet. 

"I'm not a big yoga person, so that was hard. But it was basic Hatha yoga. I loved it," he continues. "Also there's painting there. I wanted to do something that was intense, but had a holistic way, which is this."

Now he's struggling to maintain his new body.

"The only problem is the upkeep of it. Restaurant portions are way too big. And you realize everything around you is basically bad for you," he says. "It's a process."

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