Evan Agostini / Invision/AP 1 / 8
Evan Agostini / Invision/AP 1 / 8

Newlywed Cameron Diaz believes that the "fountain of youth" lies between the sheets.

The 42-year-old "Sex Tape" star opened up to Cosmopolitan UK magazine about what keeps her young, and aside from diet and exercise, she also credits love making. "It's something healthy that we need to be doing for many different reasons," Diaz, who married Good Charlotte rocker Benji Madden in January, tells the women's magazine.

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This wouldn't be the first time Diaz has promoted the benefits of a healthy sex life. "The fountain of youth [for me], let's see... I guess it's exercise, healthy diet, lots of water, lots of laughter, lots of sex," she told British Vogue in 2010. "Yes, sex, we need that as human beings. It's healthy, it's natural, it's what we are here to do!"

As for her other tips for looking good, the actress tells Cosmo UK that exercise is mandatory. "Once you commit and really put in the effort, your body goes, 'Oh, it's not okay to be without this,'" she says. "People say, 'My body rejects exercise.' No, it doesn't. Your mind rejects exercise."

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When it comes to the diet part of her lifestyle, Diaz never over indulges. "Remember, you don't have to have the whole cake, you can have a piece," the "Annie" star advises. "Don't deprive yourself. Have fun. Just be self-aware. If your equation is 80 percent good, 20 percent bad most of the time, then a little movement toward the center isn't going to affect you much."