Scarlett Johansson

She admits she has youth on her side, but Scarlett is no gym junkie.

'I'm not really the type of girl who goes to the gym for three hours a day and gets up to go jogging at 6am,' she says. 'If I had done an hour of working in the gym in the morning, I'd feel so great about myself for the next three days I'd be like, "I can eat whatever I want. I went to the gym for an hour three days ago!"'