Hot Gallery: From Skinny to Ripped! Celebrities Who Bulked Up

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Skinny: Chris Hemsworth in 2005

Eighth Annual MTV Video Music Awards

UNIVERSAL CITY, CA - SEPTEMBER 5: (L-R) M.C. Ren, Eazy-E, guest and Dr. Dre of N.W.A. attend Eighth Annual MTV Video Music Awards on September 5, 1991 at the Universal Ampitheater in Universal City, California. (Photo by Ron Galella, Ltd./WireImage)

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Chris Hemsworth Ripped Shirtless Photo Thor 2010

Patrick Riviere/Getty Images, Paramount Pictures

Ripped: Chris Hemsworth in Thor

Aussie Chris Hemsworth made a big splash as the handsome, heroic father of James T. Kirk in the 2009 Star Trek reboot. However, most people don’t believe that guy is the same one who now plays the super-jacked Marvel comic-book hero Thor in the hit 2011 film and the sequel Thor: The Dark World. Never underestimate what big-time personal training, a scruffy beard, and one heck of a hammer can do to a body.

Anthony Michael Hall Sixteen Candles Nerd Photo

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Skinny: Anthony Michael Hall in Sixteen Candles

Anthony Michael Hall Sixteen Candles Photos 2004 the dead zone

LL/GLOBE PHOTOS, INC., Marcel Williams/USA Network

Ripped: Anthony Michael Hall in The Dead Zone

Anthony Michael Hall started acting as a kid, playing the quintessential geek to perfection. His turn as the scrawny, pasty white, brace-faced Ted "The Geek" in Sixteen Candles (1984) raised the cinematic nerd bar, earning him more “brain” roles in The Breakfast Club and Weird Science. Pigeonholed by that look, Hall said goodbye to his nerdy days forever in 1990 when he appeared on-screen as Winona Ryder’s bulked-up, anger-fueled boyfriend in Edward Scissorhands. Nobody’s looked at Hall the same way since.

Brad Pitt Thelma and Louise Shirtless Photo 1991

Skinny: Brad Pitt in Thelma and Louise

Brad Pitt Thelma and Louise Ripped Troy Photos

Warner Bros.

Ripped: Brad Pitt in Troy

Okay, let’s be honest here, Brad Pitt has always been fit and fine, as evidenced by this shot of his abnormally hot six-pack in Thelma and Louise (1991). While his physique was certainly spectacular enough to seduce Thelma, Pitt didn’t possess the powerhouse body found on many of his day’s contemporary action stars. However, Pitt took his body to new heights to play the legendary Greek Achilles in Troy (2004), where his jacked arms made every ancient culture stop and say, “Conquer me, please?” Want more Brad Pitt? Check out this hot gallery that follows this sexy star's path to fame!

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Skinny: Carrot Top in 2001

Kevin Winter/Getty Images, Charley Gallay/Getty Images

Ripped: Carrot Top, Today

In case you forgot, the pumped-up and overtanned ginger comedian known as Carrot Top wasn’t always the freakishly defined specimen that struts around Las Vegas today. No, Carrot was born Scott Thompson and was an average-sized kid from Cocoa, Florida. It wasn’t until a few years into his success as a college campus stand-up comic that Scott decided to partake in serious weight lifting and body enhancements, thus creating the scarier Carrot Top we know today.

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Skinny: Chris Evans in 2005

Chris Evans Ripped Muscles Shirtless Photo 2011

Evan Agostini/Getty Images, Jay Maidment/ Marvel

Ripped: Chris Evans in Captain America

Chris Evans may have never looked as naturally scrawny as 4-F Steve Rogers in Captain America (2011), but the actor was certainly a lot more fit than phenomenal before his turn as the First Avenger last year. Sure, he looked the jock part in Not Another Teen Movie (2001) and filled out his spandex nicely as Johnny Storm in Fantastic Four (2005), but wowsers, who saw Captain America Evans coming?

Jonathan Lipnicki Kid Photo in Jerry Maguire 1996

Skinny (He Was Just a Kid!): Jonathan Lipnicki in Jerry Maguire

Jonathan Lipnicki Ripped Shirless Grown Up Photo 2011

Ryan Caliendo, PacificCoastNews.com

Ripped: Jonathan Lipnicki, Today

Holy puberty! Remember that bespectacled kid with the spiky hair in Jerry Maguire? That was child actor Jonathan Lipnicki, who starred in other Hollywood hits like Stuart Little (1999) and The Little Vampire (2000). It’s hard to keep a career when you’re not a precocious cutie anymore, so now 23-year-old Jonathan has reinvented himself as a muscled-up hottie. Here's a photo gallery that looks back on the stars of Jerry Maguire, Where Are They Now?

Ron Galella, Ltd./WireImage

(Not So) Skinny: Dr. Dre in 1991

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Ripped: Dr. Dre, Today

One of the most influential rap artists in history, Dr. Dre used to hide his body inside oversized sports jerseys and long-sleeved shiny shirts. He spent a lot of time in studios producing for rap artists like Eminem and Mary J. Blige, which kept Dre’s physique full. But in the last decade, Dre has accomplished a total body reversal, sporting some serious upper-body muscles squeezed inside some very tight shirts. Check out this gallery all about some of the hottest rappers, Before They Were Stars!

Edward Norton Rounders Premiere Photo 1998

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Skinny: Edward Norton in 1998

Edward Norton Ripped Shirtless Muscle Photo The Incredible Hulk 2008

Brenda Chase/Online USA/Getty Images, Universal Pictures

Ripped: Edward Norton in The Incredible Hulk

Thespian Ed Norton has always been lean and even a little spindly on-screen (American History X notwithstanding). However, Norton took on some mass and weight to play the scientist who doesn’t like it when you make him angry in The Incredible Hulk (2008).

Michael McDonnell/Archive Photos/Getty Images

Skinny: Madonna in 1978

Michael McDonnell/Archive Photos/Getty Images, Ian Gavan/Getty Images

Ripped: Madonna, Today

Madonna Louise Ciccone began her career as a dancer in New York City. Lean with lots of curves, Madonna learned a lot of edgy moves that brought her to the forefront and sparked her career as a mega pop star. Now 55, Madonna has beat down the march of time on her body by keeping it in rock-hard condition. Whether it’s keeping fit for tours or just maintaining for the cameras, Madonna’s got guns that make women half her age blanch.

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Skinny: Matt Damon in 2002

Matt Damon Ripped Muscles Photo Invictus 2009

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Ripped: Matt Damon in Invictus

Before the Bourne movies, Matt Damon was that skinny, good-looking kid from Boston. Sure, Damon was handsome and fit for Good Will Hunting (1997) and Ocean’s Eleven (2001), but no one thought of Matt as a potential action star. All of those perceptions changed when he transformed himself into a lean, mean killing machine in The Bourne Identity (2002). Then he was almost unrecognizable as the buff rugby star François Pienaar in Invictus (2009) and as a well-muscled rebel in Elysium.

Ryan Reynolds Skinny Young Photo 1990 Fifteen

Skinny: Ryan Reynolds in Fifteen

Ryan Reynolds Ripped Muscles Photo X-Men Origins

James Fisher/20th Century Fox

Ripped: Ryan Reynolds in X-Men: Origins

While women are more than happy to drool over Ryan Reynolds in any action role today, few remember that he started out as a kid actor in Canadian TV shows like Fifteen and The Odyssey. It took some years before his body overshadowed his snark, but by the time he starred in Blade: Trinity (2004), audiences and Hollywood were taking a brand-new look at the actor and his assets.

Taylor Lautner Skinny Young Photo Sahara Premiere 2005

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Skinny: Taylor Lautner in 2005

Taylor Lautner Ripped Muscles Shirtless Photo Twilight New Moon 2009

Ripped: Taylor Lautner in New Moon

Taylor Lautner may be best known today as Jacob Black in the Twilight films, but we remember him from his days as Shark Boy. The kid actor was able to transition his career into his teen years, but he almost got recast as Jacob for being too scrawny. Luckily, Taylor was able to bulk up between the first and second Twilight movies and now no one can imagine him without those bulging muscles.