Denying that she may have mimicked the Tinseltown trend to become too skinny, a waif-like Keira Knightley told reporters at London’s premiere of Pirates of the Caribbean: Dead Man’s Chest on Monday night: “Whatever people say about my weight they are all wrong.” 

Defending her appearance, the 21-year-old 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.”

Adorned in vintage Cartier jewelry and a low-cut, backless bronze Gucci dress, Knightley was happy to be back in her hometown. “We had such a good response in the U.S., but I’m a London girl – so it’s always special to do a premiere here,” she said.

For his part, Pirates star Johnny Depp was decked out in a fedora and sunglasses to keep his cool in the uncharacteristically hot London. He greeted fans and signed autographs for more than an hour.

Costar Orlando Bloom was also at the premiere. Press reports say he couldn’t help himself, and peeked down the front of Knightley’s gown, which opened to her belly button. “I haven’t flashed anyone yet,” she joked.

Among the other stars sighted: singer Charlotte Church, dealing with the heat in a white sundress and flip-flops, and Mischa Barton, sporting a blue baby-doll dress.

Pirates of the Caribbean: Dead Man’s Chest opens Friday in theaters across the U.S.