By Michelle Nichols

NEW YORK (Reuters) - Colombian actress Catalina Sandino Moreno made her name swallowing heroin pellets in the hit "Maria Full of Grace" but chose to take a more relaxed approach to her latest movie role -- by getting naked.

Although the 26-year-old earned a 2005 Oscar nomination for her film debut as a teen-age drug mule, her career has skirted mainstream Hollywood since then. That trend continues with her role as a young carefree singer in "The Hottest State."

In an effort to expand beyond serious characters, Sandino Moreno said she chose to play the heartbreaker in the film so she could just "have fun."

The film, which follows the joy and pain of a first love, opens in major U.S. cities on Friday.

"I just wanted to go to the set feeling that I didn't have to go to a slaughterhouse or swallow some pellets," she said, referring to slaughterhouse visits for "Fast Food Nation," an adaptation of a book on the U.S. fast food industry.

"I just wanted to go to have fun ... to be relaxed," Sandino Moreno told Reuters in an interview. "I just wanted to do something different, completely different to what I have been doing."

She admits she struggled with her decision to strip down for the first time for sex scenes in "The Hottest State" before hitting upon a novel idea for image-conscious Hollywood -- be yourself.

"I'm not perfect, I have this," she said, grabbing her thighs. "Then I realized every time you watch a movie where a girl gets naked, it's perfect, she's a model and it's not true. It's not real.

"It was kind of like a big thing for me to just go for it, to take my clothes off and be me," she said. "It was something that I really thought about, to do or not to do. Then I just said ... I'll do it. I'm normal, it's not a big deal."

'I EMBRACE IT. IT'S BEAUTIFUL'

The film industry's obsession with beauty and skinny actresses hit home for Sandino Moreno when she attended the Cannes Film Festival last year and needed a dress to wear. She said she visited two designer suites in a bid to find an outfit.

"They just had model sizes, a (U.S.) 2 or a 4, and I'm a 6. I don't think I am overweight," Sandino Moreno said. "I'm not that skinny, I will never be that skinny. So it was kind of weird."

"But I will never be like that, it's impossible, it's in my genes, it's in my blood. This is not fat, this is like my bones, it's there and I embrace it. It's beautiful," she said.

Sandino Moreno portrays a singer-songwriter named Sarah who becomes the first love for 20-year-old William, played by Mark Webber. Actor-director Ethan Hawke adapted the film from his own novel of the same name.

The actress lip syncs to another voice in the movie because time constraints prevented her from recording songs herself, and she said a music career is definitely not something she wants to pursue -- she plans to stick to acting.

"I just think you have to be good at one thing. You just have to learn that craft," said Sandino Moreno, who recently completed "Love in the Time of Cholera," which is due to be released in November. "I'm not going to launch any perfumes and I'm not going to start singing."