Amanda Seyfried "rarely" gives her best in movies.
The 29-year-old actress is currently starring in off-Broadway show 'The Way We Get By' and admits she works much harder on stage than on screen.
She said: "You can hide laziness in film, you can't hide on stage.
"You don't want to do that to people who have spent $100-400 on a ticket. You want to tell the story.
"I don't want to give anything but my best, and in films I rarely give my best."
And Amanda admits working in theatre is "tough" and requires a lot of sacrifices.
She said: "It's making me re-evaluate my ideas about where I thought I wanted my career to go.
"The theatre world is tough and you have to be willing to sacrifice a lot.
"Nobody has a personal life. It's hard to focus on anything else. I don't have time for hobbies, I barely have time for the gym and every meal I have is at the theatre.
"When I do movies, I usually knit. I also paint, but between these shows I'm either napping or meditating."
The blonde beauty also expressed her frustration at how her movie 'Lovelace' - a biopic of porn star Linda Lovelace - wasn't a box office smash, but she is very proud of the film.
She told Britain's Marie Claire magazine: "I was very frustrated by that. But I don't have any control once I've finished shooting and everyone has their own vision.
"That said, I still think it's the best thing I've ever done in terms of I respect the work I did in it - and I'm pretty self-deprecating for an actress. Playing someone else is really hard."