Kristen Bell exercises so she can eat as much as she wants.

The 30-year-old actress says she has a sensible approach to her diet and knows that if she works out she can indulge in more treats.

She said: "I'm like a jackrabbit throughout the day and like to keep moving whenever I can. And this is better than just sitting on the couch for an hour, right?

"More flights of stairs means I can eat more candy!"

In order to maintain her enviable figure, Kristen - who is engaged to Dax Shepard - and her friends do a lot of outdoor exercise.

She told Shape magazine: "My friends and I are all into staying in shape through outdoor activities. We play Ultimate Frisbee, hike the trails around Los Angeles, go rock climbing in Malibu, explore underwater caves in Palos Verdes. We're gluttons for excitement, and it keeps us fit!"

However, the 'Get Him to the Greek' beauty says she doesn't put too much pressure on herself to be super skinny and would much rather be healthy.

She said: "I like to stay fit and challenge myself but I'm not going to try to be a certain size, or weigh a specific amount. I don't own a scale. My goal is to feel good and look healthy."