By Debbie Emery - Breaking Celebrity News Reporter

Former plus size model and anorexia survivor Crystal Renn shocked people with her startling slim down earlier this week, and now an eating disorder expert is weighing in on her unhealthy look, Breaking Celebrity News can exclusively reveal.

Dressed in a skintight scarlet Zac Posen gown, Renn was a shadow of her former self when she walked the red carpet at the New York premiere of W.E. on Monday night, prompting fears she has fallen back into bad habits.