Jennifer Aniston found going make-up free for 'Cake' ''liberating''.

The 46-year-old actress usually has to pay careful attention to the way she looks so she enjoyed getting the chance to not worry about her appearance in the movie - in which she plays Claire Simmons, who is recovering from an accident who becomes obsessed by the suicide of another woman in her chronic pain support group - because it was important not to ''glamorize'' the role.

She said: ''This was not the kind of character you want to glamorize in any way.

''In my own life I've spent a lot of time dealing with having to pay attention to the way I dress and look, so playing Claire was beyond liberating in every way.

''Apart from make-up used to apply the scars, the only make-up I wore was when they were adding dark circles to my eyes.''

Jennifer admits the movie is the ''role of a lifetime'' for her but she fought hard to get the part.

She told Total Film magazine: ''It's the role of a lifetime. 'Cake' is the kind of film I've dreamed of doing for many years but I never really found a project like this until now.

''As soon as I read it, I knew I wanted to play Claire.

''I had to fight to get the part. I begged and begged [director] Daniel Barnz to give it to me because I knew I could do it and tap into all of Claire's different sides - her adventurous and sarcastic side as well as her anger and depression.

''For Daniel, it was a matter of convincing him that I was prepared to go all the way in this kind of role.''