The cover of InStyle Magazine - featuring the glamorous Catherine
She followed a rigorous exercise regime she used for her role in the musical Chicago.
The sultry beauty also recently hit the headlines for using foul language on the set of her latest movie 'No Reservations'.
She had to be even more careful on the set because 10-year-old Abigail Breslin was her co-star.
She said: "It was difficult. I'm from Wales. I have a mouth like a truck driver. The hardest thing for me making this movie was my reaction when I screwed up.
Trying to control my reactions around this little girl was so difficult. Every day one would slip out and Abigail would roll her eyes as if to say, "Here we go again."
She added: "In the end, if I screwed up, I would have to force myself to say, 'Oh poo!' or 'Oh sugar!' but it wasn't easy."
