I think it's believable that she isn't. My sister is shorter than Keira, has a smaller frame than her, and has less muscle tone but she is only slightly bigger than Knightley. Trust me, my sister can and does eat. 3+ times a day and whole meals (e.g. meatloaf, cereal, sandwiches, protein bars, burgers, fries.. 'normal' everyday foods). So yeah, I believe Keira if she says she isn't anorexic.

Hello? I'm not stupid, I have two anorexic friends. Kiera Knightly is literally starving for attention! She's full of crap, everybody in the world isn't lying, she looks too skinny and unhealthy!