In a recent post on her eponymous app, Kristin Cavallari reveals, "I haven't had fast food in years."

"Paris Hilton." The words bring to mind certain images: french fries, hamburgers, chicken nuggets, Whoppers, Big Macs, chicken sandwiches, remember chicken fries?, coffee in thick styrofoam. But not anymore. The known person has given up fast food, and you won't believe how she can feel the difference.