Celebs are under a slew of scrutiny about their bodies, so it's not surprising that their weight loss can be pretty extreme at times.

Whether or not these famous faces were even overweight to begin with (many looked great with meat on their bones) is up for debate, and for some celebs, their weight loss was more dramatic than healthy.

Some looked a lot better (get it done, Kelly Osbourne!) while others looked gaunt and sick (Matthew McConaughey, we missed your muscles -- we're glad they're back) following their strict regimens. In any case, for some stars, their fluctuating waist lines provided some of us with guilt, some of us with inspiration and all of us with intrigue. Take a gander at the most dramatic celeb slim downs below!

Kelly Osbourne

Scott Gries / Frederick M. Brown, Getty Images

Angelina Jolie

Kevin Winter / Andreas Rentz, Getty Images

Kirstie Alley

Evan Agostini / Anna Webber, Getty Images

Christian Bale

Frazer Harrison / Handout, Getty Images

Mila Kunis

Peter Kramer / Frazer Harrison, Getty Images

Cheryl Burke

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Hilary Duff

Evan Agostini / Frazer Harrison, Getty Images

Courtney Love

Frazer Harrison / Kevin Winter, Getty Images

Nicole Richie

Amanda Edwards / Jamie McCarthy, Getty Images

Jonah Hill

Jason Merritt (2), Getty Images

Snooki

Jason Merritt / Cindy Ord, Getty Images

Charles Barkley

Ethan Miller / Jim Rogash, Getty Images

Kim Kardashian

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Matthew McConaughey

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Renee Zellweger

Kevin Winter (2), Getty Images