Ashton Kutcher's Steve Jobs Diet So much for an apple a day keeping the doctor away: Ashton Kutcher says he became ill on an all-fruit diet while preparing for his film about Apple visionary Steve Jobs. The 34-year-old actor says he ate only fruit for his turn as Jobs, in keeping with the tech mogul's purported diet. USA Today reported that after "jOBS" premiered last Friday night at the Sundance Film Festival in Utah, Kutcher said, "I went to the hospital like two days before we started shooting the movie. I was like doubled over in pain. My pancreas levels were completely out of whack. It was really terrifying. Photos: Ashton Kutcher as Steve Jobs According to Walter Isaacson's 2011 biography, Jobs often went on fruit-only diets, and they even served as inspiration for his company's name. "I was on one of my fruitarian diets," Jobs reportedly told Isaacson of his decision to name the computer company Apple. Jobs died of pancreatic cancer in 2011. A preview clip of "jOBS," which hits theaters April 19, was released last week, and the man who co-founded Apple with Jobs, Steve Wozniak, was not impressed. "What I saw was just so far from anything that really happened or [was] said in those days," he told ABC's "Good Morning America." Apple Co-Founder Steve Wozniak Criticizes 'jOBS' Biopic Film Wozniak is serving as a consultant on another Jobs movie that Aaron Sorkin is writing. As for Kutcher, he is not the only actor to push the boundaries of health for a role. Click through to see six more who've gone to extreme and sometimes unhealthy measures to get into character: Matthew McConaughey Matthew McConaughey is back on the road to being a beefcake, after dropping more than 40 pounds for his starring role in "Dallas Buyers Club." "I was 135 pounds, and now I'm up to 160 pounds, so I'm done with that and on my way back," the 43-year-old actor told People magazine earlier this month. McConaughey stopped eating in order to play an AIDS patient turned drug dealer in the upcoming movie. "It's a bit of a spiritual cleanse, mental cleanse," McConaughey told Larry King last August during an appearance on the veteran newsman's Ora TV online show. [I'm] drinking a lot of tea. "It takes a while for your body to understand that it has to feed off of itself, and that you're not going to give it something else from the outside," the actor said. I should not look healthy by the time I'm doing this. After ditching his intense diet, he started packing on the pounds with the thing he's been craving for months -- a cheeseburger. I got the cheeseburger, and then I sat there for 25 minutes and doozied it up," he told People, adding that his goal weight was 165 pounds. 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 movie version of "Les Miserables," the 30-year-old actress subsisted on a 500-calorie diet of radishes and hummus. 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!'" she told Allure magazine last August. On top of that, she worked 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. Her extreme preparation paid off: Hathaway earned raves for her turn as Catwoman and an Oscar nod for her role as Fantine. She recently took home the Golden Globe and Screen Actors Guild awards for best supporting actress for "Les Miserables." 50 Cent When Curtis Jackson, better known as rapper 50 Cent, decided to make "All Things Fall Apart," a movie about his childhood friend's cancer battle, he committed to getting as skinny as possible. "I had so much muscle on me that it was hard for me to lose definition even as I got lighter and slimmer," he told Parade magazine in 2010. I started running to suppress my appetite. Toward the end it was really difficult. It was like, if I don't get close enough to what my best friend looked like to me at that point before he passed, then I'm not doing the story any justice. When the going got tough, he took to the Internet to read how actors like Christian Bale and Tom Hanks lost weight for their own projects. "I actually got on the computer," he told The Associated Press in 2010. When it started getting difficult, I was looking to see what their experience was like, and I got a chance to see all the interviews they had at different time periods when they were doing promotion for the projects. Natalie Portman When Natalie Portman dropped more than a dozen pounds 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" in 2010. 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 ... was really a challenge. As soon as filming wrapped, Portman, who'd danced as a kid, was happy to leave the ballet world behind. She told "Access Hollywood" in 2010 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. Mila Kunis Portman's "Swan" co-star Mila 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 5-foot-3-inch actress told E! Online in 2010. 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. Gwyneth Paltrow Gwyneth Paltrow packed on 20 pounds to play an alcoholic singer in 2010's "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, afterward. "The nightmare thing about it is I had to stop working out," she told Chelsea Handler on "Chelsea Lately" in 2010. 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 station 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. Amanda Seyfried Amanda 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," Seyfried told Esquire in 2011 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 in 2012. It's twisted, but I wouldn't get the roles otherwise.