Carey Mulligan gained weight while on a ''hunger-strike diet''.

The 29-year-old actress wanted her portrayal of suffragette Maud in 'Suffragette' to seem realistic so cut out sugar and other fatty foods - but realised the eating plan she made for herself was ''complete b*****s'' as some of her snacks were still calorific.

Speaking to the film's writer, Abi Morgan, she said: ''You remember my whole 'hunger-strike diet' on 'Suffragette?'

''The idea was to make me look kind of malnourished, but not in a serious way, it was more of a psychological thing. Actually, it did make me feel more stoic.

''But it turned out to be complete b*****s. I gained weight. Even though I had no sugar or fruit or any of those things, I was told I could have nuts. So I ate massive packets of nuts every day.

''I never weigh myself, but I did weigh myself before and after, just to see, and I gained three kilos and all of my trousers didn't fit.''

Carey always tries to be in the right physical shape for the characters she plays, and even though she stripped for her role in 'Shame', she admits she ''actively'' ate whatever she wanted and ''drank loads'' of alcohol.

She added to Harper's Bazaar magazine: ''For 'Far From the Madding Crowd', the character is a country lass, so I wanted to be pretty strong, and I spent the entire film running up and down hills. I've got a farm, so I'm used to that. But I wanted to be someone who could lift a hay bale. And they're very heavy. So I liked going to the gym for that.

''But for 'Shame' I actively ate whatever I wanted to, drank loads and looked like hell. And that was the film I decided to take all my clothes off in.''