I think I finally understand Paris Hilton's problem.

"You need fat to produce your hormones," says Beverly Whipple, professor emeritus at Rutgers University and president of the World Association for Sexology. "Cholesterol is metabolized in the liver, and you get your testosterone and estrogen, which you need for your sex drive."

Because she subsists mainly on a diet of Red Bull and cheese, and therefore very little fat, she has essentially become a hollow shell with a vagina. Which would be kind of like a guy poking a wooden sex doll. With splinters.

In nearly related news: Paris Hilton now owns a monkey? No, really...she does. Which completely makes sense because her pets have always kind of been hideous, right? Tinkerbell. That smelly ferret...Nicole Richie. And now a monkey. That's hot.