The "Underworld" actress plays real-life working class foster mum Ingrid Carpenter in "Suicide Squad" star Adewale Akinnuoye-Agbaje's autobiographical film, but she admits she was a little puzzled when the actor and director singled her out to play his 'mum.'
"She doesn't physically resemble me," Kate laughed during an appearance on "Live With Kelly & Ryan", "and we speak very differently."
Because Ingrid is also much heavier than Kate, the Brit wanted to pig out and pile on a few pounds the old-fashioned way, but the film came together so fast there just wasn't enough time, so she had to rely on body padding instead.
"I would have eaten much more cheese and gained all that weight but, yes, there's a limit to how much you can eat in three or four weeks," she shares.
But she was very happy with her giant fake boobs.
"What they stuff them with, which I didn't know, is lentils," she adds. "If they stuff a man's swim shorts it's also lentils, weirdly... We had one scene where it rained and my boobs started sprouting."