When you're an actor, you have to be willing to do whatever it takes to nab that dream role -- including dropping and gaining weight to portray a character.
And that's exactly what some of Hollywood's biggest stars have done.
From George Clooney and Matt Damon to Charlize Theron and Renee Zellweger, celebrities have packed on the pounds (and we're talking serious, serious pounds) for films they are truly invested in.
But a little cellulite never hurt anyone, especially when all those cupcakes and donuts put you in the running for an Academy Award.
Check out 15 stars who've chowed down for movie roles:
George Clooney gained 30 pounds to play former CIA agent Robert Baer in 2005's "Syriana." Thankfully, the weight gain paid off -- he won an Oscar!
Damon gained 30 pounds for his role in "The Informant!" in 2009, but the actor says packing on the weight was "fun." “It was very, very easy to gain the weight. Very, very fun,” he <a href="http://www.accesshollywood.com/matt-damon-talks-gaining-weight-for-the-informant-it-was-very-very-easy_article_22621">confessed</a>. “I just basically ate everything I could see for a few months.”
Zellweger gained 28 pounds (twice!) for her lead role in "Bridget Jones's Diary" and "Bridget Jones: The Edge of Reason." Reportedly, she'll be reprising her famous character for another installment of the franchise, "Bridget Jones's Baby." Another round of weight gain?
Theron gained 30 pounds to play serial killer Aileen Wuornos in "Monster." She also gained something else along the way -- an Academy Award for Best Actress!
Leto put on 67 pounds to play John Lennon's assassin, Mark David Chapman, in "Chapter 27." The movie didn't get the best reviews, and Leto's body took a beating. Let's just say he probably won't do it again.
Paltrow added 20 pounds to her thin frame for her role as a washed out country star in "Country Strong." <a href="http://www.people.com/people/package/article/0,,20316530_20440520,00.html">With the help of her personal trainer</a>, Tracy Anderson, she dropped the pounds in two weeks!
Ryan Gosling and his "Blue Valentine" co-star Michelle Williams each gained 15 pounds for the movie, in which they played a couple stuck in a troubled marriage.
Roberts gained 10 pounds to accurately portray Elizabeth Gilbert in "Eat, Pray, Love," which is based on a true story. Gilbert gained 30 pounds in real-life, so Roberts figured she needed to pack on some pounds to be authentic.
Not only did Bale lose over 60 pounds for his leading role in "The Machinist," he also gained tons of muscle weight to play Bruce Wayne, a.k.a. Batman, in Christopher Nolan's epic trilogy.
Russell Crowe gained 63 pounds for his role in 2008's "Body of Lies." He did it <a href="http://socialitelife.com/russell_crowe_explains_weight_gain-09-2008">with a little help from his food friends</a> -- cupcakes and cheeseburgers.
Swank didn't just have to gain weight for her role in "Million Dollar Baby," she had to bulk up! The actress put on 19 pounds of pure muscle and walked away with an Oscar.
In 2000, the normally buff Bana put on 28 pounds to play a murderer in "Chopper." But, no worries. Bana was allegedly back in tip-top shape within months.
The former "Third Rock From the Sun" actor turned into an action star for the final Batman flick, "Dark Knight Rises." Just like his co-star Christian Bale, Gordon-Levitt packed on the muscle (and it shows).
Robert De Niro
How could we forget De Niro, who made gaining weight for a role cool thanks to "Raging Bull"? He famously gained 60 pounds for the movie and paved the way for Hollywood body transformations.
The funny guys is currently eating up a storm while his wife, Anna Faris, tries to shed her baby weight. He has already gained 40 pounds since June in preparation for his role as a lawyer in the upcoming comedy "Starbuck."