Gwyneth Paltrow plays poet Sylvia Plath in Sylvia

She said she expected to do fewer but more challenging roles in the future.

"I spent my 20s just working back to back to back. I don't even know how many films I did," she said in an interview with news agency Reuters.

Paltrow said she planned to make more films such as the forthcoming Sylvia, in which she plays the role of tragic US poet Sylvia Plath.

"I took a year off when I was 29, and I sort of lost the joy. I lost the thread of why I was doing it," the actress, 31, said.

"I think also the whole celebrity part of it really just put a bad taste in my mouth, all the time," she said. Before dating current partner Chris Martin of Coldplay, Paltrow went out with Brad Pitt and Ben Affleck.

Poet role

The death of her father, director Bruce Paltrow, also forced her to rethink her career, she said.

"I thought, from now on I want to do things that are worth my time. Because we are all dying.... Get something out of your life and make your life worth something."

The actress said the role of Plath, the US poet who was married to poet laureate Ted Hughes and killed herself in 1963, was "why I became an actor in the first place".

"I think that the experience of playing her really changed me. It was so difficult and so harrowing, but I got so much back from it, that I thought: I really don't want to waste my time doing things that are mediocre," she said.

Paltrow said did not plan to make more films such as the romantic comedy Shallow Hal, where she donned a fat suit to play an obese woman.

"I'm glad I've done everything I've done because it's all part of who I am and all part of my experience, but I have changed the way that I see things."