Kristen Stewart talks dieting and her baby belly

With filming on Twilight Breaking Dawn starting in less than a month, Kristen Stewart is watching what she eats.

The 20-year-old actress has spoken about dieting – and her fake baby belly.

“I want a cheeseburger so badly, but, you know, I have to be a vampire in a few weeks,” Kristen told the LA Times‘ Amy Kaufman at lunch in Los Angeles, before opting for a veggie burger instead.

Her character Bella will be spending a lot of time pregnant with her first child in the upcoming flick, which means Kristen has to wear and uncomfortable fake bump.

“I’ve worn it. It’s … crazy. I’ve done fittings,” she said. “It gets immense. It gets so massive at some point that it actually looks inhuman. Like it’s hurting her. There are striations of bruises.”