1. Christian Bale and his extreme thinness in 'The Machinist'
One of the most amazing performances in cinema. Christian Bale played Trevor Reznik, a man who suffered from insomnia. He began to lose kilos four months before the shoot until he reached 50 kilos (he lost 28 in total). He wanted to go down to 45, but the producers forbade it because he might have health problems (and certainly, judging by the film, he didn't need to). In addition, as soon as the filming ended, he had to recover his weight and 30 more kilos; he was beginning to prepare for his role in Batman Begins.
2. Tom Hardy played the real criminal Bronson
Tom Hardy played the role of criminal and kidnapper Charles Bronson, who is currently in Woodhill Prison (UK). The actor had several phone conversations with him and they even met several times in jail. Bronson himself acknowledged that he was impressed by how Hardy had changed his physique for the role and how well he imitated him.
3. Jake Gyllenhaal as a boxer in 'Southpaw'
Gyllenhaal has been training six hours a day for six months to gain seven kilos of muscle. According to Antoine Fuqua, the film's director, "We literally turned him into a beast."
4. Chris Pratt in 'Guardians of the Galaxy
He weighed a whopping 300 pounds when he auditioned for the Marvel movie. In his own words, he lost 60 kilos in six months thanks to "three or four hours a day of hard and consistent work."
5. Natalie Portman in 'Black Swan
"There were nights that I literally thought I was going to die," said the young actress. She lost nine kilos and her diet was based on a few carrots and almonds. In addition to the physique that her body had to endure with such a strict diet, she had to practice dancing for eight hours a day. Portman acknowledged that after this role she realized how much an interpretation affected real life.
6. Chris Hemsworth, an example of consistency in 'Thor'
He trained with Duffy Gaver, a Navy SEAL until he gained twenty pounds (and all in muscle!). According to his trainer, people believed that he was doping, but it was about following a diet based on a lot of red meat and protein shakes. "I just wanted to be like Thor."
7. Matthew McConaughey and his role as a drug addict
He lost almost 20 kilos and won the Oscar for best actor in "Dallas Buyers Club." Despite how dangerous these conditions were for his health, he acknowledges that he had a lot of mental energy throughout the shoot.
8. Charlize Theron and her transformation into 'Monster'
One of the most striking examples of interpretation. Despite having gained eleven kilos based on donuts and chips, the actress admitted that she did not consider that she was fat. What cost her the most was leading the lazy lifestyle that characterized her character to get into the role.
