Sucker Punch star Emily Browning has revealed she and her female co-stars all enjoyed weekly cheat nights from their strict diets for the action movie.
The Australian actress, who stars as Baby Doll in Zack Snyder's dark new action fantasy, and the rest of the cast braved the cold in London's Leicester Square for the film's UK premiere.
Emily, who endured military and martial arts training for the role, revealed: "We had Wednesday night cheat nights.
"We were all on strict diets, high protein, to build up muscle mass. But Wednesday nights we would all go out and eat cakes together, or just have a cheat night and get together.
"But we were hanging out all the time and we would have sing-a-longs. It was lots of fun."
The video game-inspired film, about a girl who enters a dark dream world to escape the brutality of her real life, also stars High School Musical's Vanessa Hudgens, Bright Star's Abbie Cornish, Jena Malone, Jamie Chung and Carla Gugino.
Zack admitted he enjoyed putting the girls through their paces.
He said: "I felt good 'cause I like to torture them a little bit.
"I feel like they bonded together over it, so it's pretty great."
But Disney star Vanessa insisted she loved the action, and said: "It was amazing. It was so much fun. Definitely one of the most exhilarating things I've done."