If is amazing the lengths that actors will go to to get ready for their roles. Some lose weight, other gain weight, while some undergo a transformation using make up and prosthetics.
Jennifer Aniston in Cake
Jennifer Aniston is back on the big screen this week with her new film Cake, in which she strips back the glitz and glamour of Hollywood to take on the role of a woman who is struggling with grief and injury after a car accident.
We take a look at some of the transformations that actresses have undergone for the big screen in recent years.
- Charlize Theron - Monster
It has been over a decade since Monster hit the big screen - yes, it really was back in 2004, and Charlize Theron was unrecognisable as she took on the central role of Aileen Wuornos.
Patty Jenkins wrote and directed the film, which was about serial killer Wuornos - who was executed in 2002 for the murders of six men.
Not only did Theron gain weight for the role, but she also had her skin weathered - she had her skin layered with washed off tattoo ink to get the desired look.
The beautiful actress also wore dentures and her hair thinned to play her the most famous role of her acting career.
The transformation was incredible. Theron went on to win the Oscar for her central performance and was the toast of the award's circuit that year. It remains one of the finest moments in her career.
- Rooney Mara - The Girl With The Dragon Tattoo
Rooney Mara took over the role of Lisbeth Salander in 2011, when David Fincher brought an American adaptation of the book to the big screen.
Mara was cast in the central role of Salander, which was a role that was to see her star rocket. However, to take on the role, she had to undergo a radical transformation.
The actress underwent a drastic haircut as well as four piercing in each ear as well as her brow and nipple. The result was the fierce looking and no-nonsense Lisbeth Salander.
It was a radical new look for Mara, but it was all worthwhile as she picked up her first Best Actress Oscar nomination for her central performance in the film - she lost out to Meryl Streep for The Iron Lady.
- Cameron Diaz - Being John Malkovich
Cameron Diaz grabbed everyone's attention back in 1994 when appeared in that red dress in The Mask, which was her big screen debut. However, when she appeared in Being John Malkovich in 2000 she had a very different look.
The movie saw her team up with director Spike Jonze, and while it wasn't a transformation that required major weight loss or gain, it is not still no how we are used to seeing Diaz on the big screen.
And because there was little physical description of the character in the script, Diaz had no idea how she was going to look in the film. She certainly did not know that audiences were not going to recognise her in the movie.
With wild frizzy hair, minimal makeup, and a frumpy style, Diaz was unrecognisable when she appeared in the film as Lotte Schwartz, the wife of John Cusack.
- Nicole Kidman - The Hours
Nicole Kidman teamed up with Stephen Daldry in 2003 to take on the role of writer Virginia Woolf, who was struggling with depression and mental illness as she tried to write her book Mrs Dalloway.
The movie followed three women; Wolfe in the 1920s, Laura Brown in the 1950s, and Clarissa Vaughan in 2001, and how they are all interconnected by the novel Mrs Dalloway. Julianne Moore and Meryl Streep joined Kidman on the cast list.
However, it was only Kidman that underwent a transformation to play Woolfe as a prosthetic nose totally changed the way that she looked. Add on some rather dowdy looking clothes and Kidman was truly able to dissolve into her character.
Kidman's looks and terrific performance earnt her a first Best Actress Oscar, as well as a Golden Globe, Bafta and a string of other awards.
- Renee Zellweger - Bridget Jones's Diary
We have seen a whole host of weight gains and weight losses over the years from both actors and actresses... and Renee Zellweger went under quite a transformation herself when she landed the role of Bridget Jones.
Bridget Jones's Diary is based on the book of the same name by Helen Fielding and hit the big screen back in 2001.
Zellweger put on twenty pounds to take on the role of the Jones - whose yo-yoing weight plays a major part in the film. Zellweger also worked hard on her English accent as she prepared for the film.
Bridget Jones's Diary was a movie that sent Zellweger's star rocketing as she went on to picked up a Best Actress Oscar nomination for her performance.
- Glenn Close - Albert Nobbs
Glenn Close is one of the best actresses of her generation and returned to the big screen in 2012 with Albert Nobbs, which was based on the novella The Singular Life of Albert Nobbs by George Moore.
The movie saw Close take on the title role in the film, a woman who is living as a man in order to find work in the tough environment of 19th century Ireland. This was not a role new to Close, having played the title character in a stage production back in 1982. She spent over a decade trying to bring it to the big screen.
Close underwent two and a half hours of makeup every day to become Albert - which included prosthetic nose and ears as well as a ginger wig. Janet McTeer went through a similar process to play Hubert Page in the film - another woman posing as a man.
Close and McTeer were recognised for the work as they received Best Actress and Best Supporting Actress Oscar nominations.
Other actresses that have undergone transformations for roles include Natalie Portman and Mila Kunis for Black Swan, Anne Hathaway for Les Miserables, and Mariah Carey in Precious.