Sienna Miller's latest film used a little special effects trickery to improve the star's much talked about looks.

The 25-year-old recently raised fashion eyebrows by wearing control pants outside her tights to a New York premiere.

She strips off for her role as Andy Warhol's muse Edie Sedgwick in her latest film, Factory Girl.

The star added: "They spray make-up all over your body so you don't see the stretch marks that we girls all have.

"I don't eat salads and I don't drink skinny coffee."

She went on: "I do run around a lot, but I'm not healthy. One day I'll wake up and my bum will be on the floor."