8 Celebs Who Stay in Shape Through ... Sex

Celebrity diets usually sound a little weird and very unpleasant, but not this one: Kim Kardashian lost seven pounds in seven days … on the "sex diet." What's that, you ask? Well, according to a friend of Kim's, you just have a whole lot of sex (in Kim's case, with Kanye West), thus burning calories and also keeping your appetite in check. The Frisky rounds up seven more celebs who think like Kim:

• How does Mandy Moore stay in shape? "It's sex! Lots and lots of sex with my husband Ryan!" she once said. "Did you know it burns 360 calories per hour? It's a total body workout!"

• Cameron Diaz agrees: Her recipe for a great bod is "exercise, healthy diet, lots of water, lots of laughter, lots of sex—yes, sex."
• Bombshell Pamela Anderson barely even hits the gym, she once revealed. "Looking good to me has always been because of the amount of sex I’m getting," she said. "I’ve hardly been a member of a gym and I can’t follow diets."

Click to see who else is following this steamy "exercise" regimen. (More celebrity stories.)