Stress is getting to Sienna Miller's figure

Sienna Miller has been under a microscope - and a ton of stress - ever since her then-fiancé Jude Law admitted to having an affair last July. Though she has always had the figure of a model, friends are now worrying that the increasing pressure on the actress has caused her to lose too much weight. According to British gossip website, FemaleFirst, she has “shrunk to a tiny size 6� - the equivalent of a size 2 in America.

"Some of her friends are worried about how thin she is getting…Sienna's been very emotional and is finding it hard to work up any kind of appetite," an insider said. And winning the role of Edie Sedgwick, the rail-thin muse of Andy Warhol, hasn’t helped matters. "Sienna has submerged herself in the part of Edie, who was very, very slim. So she's cut out all fatty foods, including breakfast fry-ups, and is sticking to salads. She's got into the habit of eating less and smoking more…there's no more snacking in between meals or eating several courses," the source said.

Certainly not helping Sienna’s state of mind is the fact that her recent love interest, Hayden Christensen is still dating his girlfriend, Lola Skye. Sienna and Hayden started forging a relationship while filming Factory Girl and were even seen sharing clothes. But Hayden’s not ready to say goodbye to Lola yet and has been photographed kissing her in recent weeks.