Hollywood star Cameron Diaz has admitted the secret to her svelte figure is having lots of sex. Never one to mince her words when it comes to matters of the body, the 42-year-old actress has said plenty of action between the sheets is a natural thing to do to keep fit.

"It's something healthy that we need to be doing for many different reasons," she told Cosmopolitan magazine.

She also said it was important to discipline yourself to do other forms of exercise – even if you are not in the mood. "You have to just do it. Once you commit and really put in the effort, your body goes 'Oh, it's not OK to be without this'," Diaz said. "People say: 'My body rejects exercise.' No it doesn't. Your mind rejects exercise."

The Sex Tape actress, who recently married Good Charlotte rocker Benji Madden, said having a balanced diet was also key to well-being, along with not missing out the occasional odd treat.

"Well-being is an equation. Remember, you don't have to have the whole cake, you can have a piece," she said. "Don't deprive yourself. Have fun. Just be self-aware."

"If your equation is 80% good, 20% bad most of the time, then a little movement toward the centre isn't going to affect you much."

Diaz caused a stir in 2014 when she released The Body Book in which she spoke about her concern of women having their pubic hair removed when it is necessary for biological purposes.

"I'm really concerned that young girls are making choices to get rid of something that is there for purpose. It's like saying, 'I don't need my nose'," Diaz told the Daily Mail, adding "besides it's a pretty draping that makes it a little mysterious".