Rebel Wilson lost more than three kilos in just four days on the set of the Cats movie.
The Aussie stars alongside Taylor Swift, James Corden, Judi Dench, Jennifer Hudson, Idris Elba and Ian McKellen in the musical film directed by Tom Hooper.
But the comedian found shooting her scenes was "pretty uncomfortable" due to the high temperature on set.
"I lost eight pounds (3.6kg) shooting my number in four days," Wilson told Entertainment Tonight.
"One, because there's a lot of physicality … but also, they heated up the set very high, to almost 100 Fahrenheit (37.7 Celsius), so that we could never cool down. These people are like, the best dancers in the whole world, so they can't cool their muscles down or they could get an injury and they'd be out of the film … So they'd heat up the set like a sauna so we would never cool down, but (it) made it pretty uncomfortable."
When the first trailer for Cats was released in July, it received a harsh reaction from people who were shocked by the "digital fur technology" that turned the actors into felines.
Wilson previously told Cosmopolitan that she wasn't bothered by the reaction the trailer received.
"I loved the reaction," she said. "I think it was a bit polarising and people will be super curious to see the finished product. What you got in that trailer was just some small samples of it, but it's going to be such a big movie."