7 Incredible Celeb Body Transformations

"It wasn't so Fantine would look hot," Anne said of her weight loss when on the Late Show With David Letterman. "It was all to look like she'd gotten really, really ill." Short Hair Ideas: Pulled Forward Vs. Slicked Back

Demi Moore spent most of the 90s covered up in several layers (save for that little movie Striptease). Try on Demi Moore's looks in the Makeover Studio!

In 2003, Demi stripped down to a bikini for Charlie's Angels: Full Throttle to show what was underneath all those clothes: an amazing bod! Celebrities' Weirdest Beauty Secrets

Hillary Swank is naturally very lanky, but to take on the role of Maggie in Million Dollar Baby, she had to build up a boxer's body. Try on Hilary Swank's looks in the Makeover Studio!

Hilary was able to build those bulging biceps by reportedly consuming up to 4,000 calories each day. Her diet included drinking protein shakes every 90 minutes, including during the middle of the night. Starving By Lunch? How To Make Over Your Breakfast

Rene Zellweger always shows up on the red carpet looking lean and muscular. Unless, that is, she is preparing to play a woman who struggles with her weight. Try on Renee Zellwger's looks in the Makeover Studio!

For Bridget Jones' Diary and its sequel, Rene packed on the pounds to look more fleshy. But as soon as each film wrapped, Rene slimmed down just as quickly. 10 Flattering Hairstyles For Round Face Shapes

To prepare for Black Swan, Natalie Portman had to look and move like a professional ballet dancer. Try on Natalie Portman's looks in the Makeover Studio!

Natalie started training and toning her body a year before shooting began. She also had to cut 20 lbs. from her petite frame. During one of her many acceptance speeches for the role, she said her nutritionist would tell her to cut cravings at night by drinking a glass of milk. The Lazy Girls Guide To Getting Fit

It's hard to believe this is the same Rooney Mara who we saw in The Girl With The Dragon Tattoo. Everything from her hair to her body weight was changed for the film. Try on Rooney Mara's looks in the Makeover Studio!

To play Lisbeth Salander, Rooney had to get down to a staggering 98 lbs. While that sounds miserable, the nipple piercing she had to get sounds worse! 10 Shocking Celebrity Transformations

Before Michelle Williams became Marilyn, Sienna Miller's transformation into Edie Sedgwick was the most talked about makeover in Hollywood. Try on Sienna Miller's looks in the Makeover Studio!

In an interview, Sienna revealed that although her director insisted she not lose any weight for the Factory Girl role, she intended to anyway. The Breakfast That Helps You Lose Weight