The skinny on Keira Knightley is that she's not too skinny. So she says.

The Pride and Prejudice star has denied reports that she is anorexic, telling reporters on Tuesday that she is "quite sure" she doesn't suffer from the eating disorder and that she was surprised to even be questioned about it.

"[The press] said to me yesterday, 'How does it feel to be called anorexic?' and I had no idea that I was. I can safely say that I'm not," she said at a press conference.

Speculation about Knightley's health began after the super-slim actress walked the red carpet at the London premiere of Pirates of the Caribbean 2: Dead Man's Chest in a barely-there metallic Gucci sheath that left little to the imagination.

While her look was called "stunning" by some, others saw her prominent skeletal structure as a warning sign that the 21-year-old Oscar nominee had succumbed to the weight-obsessed pressures of Hollywood.

In spite of her bony appearance, Knightley maintained that she was in good physical shape.

"Whatever people say about my weight they are all wrong," she said.

"Hollywood is all about the way you look and I don't think that's the healthy thing for anyone. But if you're strong and comfortable with yourself then you're going to be fine."

She explained that she is very familiar with anorexia, having been close to a number of people who battled the disease.

"I've got a lot of experience with anorexia--my grandmother and great-grandmother suffered from it, and I had a lot of friends at school who suffered from it," she said. "I know it's not something to be taken lightly and I don't."

Even so, photographs of Knightley are often posted as "thinspiration" on Websites and blogs primarily frequented by young women struggling with eating disorders, who see the actress' rail-thin physique as ideal. (Other celebrities often cited as "thinspiration" include Mary-Kate Olsen and Nicole Richie, both of whom have acknowledged battling eating disorders.)

However, Knightley has said she has no interest in being a role model for her young fans.

"I reject being a role model for a young person," she said. "I think it's completely ridiculous, the idea that you put someone up there and say, 'That's how you should behave.'"

Apart from her star turn in the second Pirates film, which opens Friday, Knightley is the new face of Chanel's Coco Mademoiselle fragrance, for which she will begin appearing in print and TV ads next year,

Still ahead, she'll star in the third film in the Pirates franchise and in Atonement, the big-screen adaptation of Ian McEwan's novel by the same name.