There are diets and then there are diets. Take, for example, Anne Hathaway: in preparation to fit into her Catwoman suit for "The Dark Knight Rises" and play the tuberculosis-ridden prostitute Fantine in the upcoming film version of "Les Miserables," the 29-year-old actress subsisted on a 500 calorie diet of radishes and hummus.
"I'm on day six of detox," she told the latest issue of Allure magazine, adding "this diet makes me break out, so I love that. Nothing like living on hummus and radishes and then be all, 'And I got a pimple. Yeah!'"
On top of that, she's been working out.
"The Catwoman suit. It was a psychological terrorist," she said. "... the suit, thoughts of my suit, changing my life so I would fit into that suit ... it dominated my year. I went into the gym for 10 months and didn't come out."
Yikes. Hathaway's not the only actress to push the boundaries of health for a role. Click through to see four other actresses who've gone to extreme and unhealthy measures to get into character:
When Portman dropped more than a dozen to play a ballerina in her Oscar-winning movie, "Black Swan," even her director worried the petite actress had gone too far.
"At a certain point, I looked at [Natalie's] back, and she was so skinny and so cut," director Darren Aronofsky told "Access Hollywood." "I was like, 'Natalie, start eating.' I made sure she had a bunch of food in her trailer."
A year before shooting "Swan," Portman went through extreme ballet and cross-training, shedding 20 pounds from her 5-foot-3-inch frame.
"I think it was just the physicality of it all that was the most extreme," she told UsMagazine.com. "I mean, I had never gotten that much training -- to be doing five-to-eight hours a day of [it] was really a challenge."
As soon as filming wrapped, Portman, who danced as a kid, was happy to leave the ballet world behind. She told "Access Hollywood" that she immediately ceased working out and began carbo-loading to bulk up again.
"I was like, pasta, pasta, pasta! No working out," Portman said. "It was pretty immediate. I was ready to leave the ballet life.
Portman's "Swan" co-star Kunis also dropped 20 pounds to play a ballerina.
For three months, the "That '70s Show" alum trained, through ballet, cardio exercises and Pilates four-to-five hours a day, seven days a week.
In the end, she became frightened by her own reflection. "I could see why this industry is so f**ked up, because at 95 pounds, I would literally look at myself in the mirror, and I was like, 'Oh my God!'" the five-foot-three-inch actress told E! Online. "I had no shape, no boobs, no ass. ... All you saw was bone. I was like, 'This looks gross.'" She told E! that it took her only five days to put the weight back on.
Paltrow packed on 20 pounds to play an alcoholic singer in "Country Strong," but admitted she panicked at the thought of not being able to stick to her strict diet and workout regimen, which includes exercising two hours a day, six days a week.
"The nightmare thing about it is I had to stop working out," she told Chelsea Handler on "Chelsea Lately." "At first I panicked, so I would work out a little bit and then I had to lie and be like, 'No I didn't work out.' I'd be on the treadmill and be like, 'I really have to stop this'."
Her trainer, Tracy Anderson, also had a hard time watching Paltrow bulk up.
"That was tough for me because we've worked so hard on her body," Anderson told ABC News' New York affiliate WABC. "She went down from six days a week of training to three, and she ate everything in sight. Fried chicken, mashed potatoes. They filmed in Nashville, so it's a good place to have some comfort food."
But even if few others seemed to notice a heavier Paltrow, the actress couldn't wait to shed the excess with Anderson's combination of dance, cardio and weight exercises.
"It didn't take her very long to lose the weight. It only took her a couple of weeks. It didn't want to be on her anyway. Extra weight isn't something that she owned," Anderson told WABC.
And it was just in time for her debut singing appearance at the Country Music Awards.
Seyfried credited the raw food diet for helping her get the slim physique she displayed in 2009's "Chloe."
"It's intense. And sort of awful," Seyfriend told Esquire of the diet that forbids eating cooked or processed foods. "Yesterday for lunch? Spinach. Just spinach, spinach and some seeds."
But Seyfried was willing to suffer for her art.
"I have to stay in shape because I am an actress," Seyfried told Glamour magazine. "It's twisted, but I wouldn't get the roles otherwise."