Curious to know how celebrities squeeze fitness into their daily lives? Want to know the secrets of the stars? Bi-weekly our That's Fit fitness expert Fitz sits down with the celebs we want to know more about, and digs out their great and not-so-great methods to staying healthy.

Eric Stoltz has one of those careers any actor would kill for. Fast Times at Ridgemont High, Mask, Pulp Fiction ... the list goes on and on. He's currently on a tear, directing all sorts of hit primetime shows too, but this week we sat down to chat about his guest role on ABC's Grey's Anatomy. My opinion: Eric is really smart, relaxed and funny. He also happens to know the secret to losing weight -- you might be surprised by how simple it actually is!

Fitz: You're playing a serial killer on Death Row for a couple of weeks on ABC's Grey's Anatomy. Any similarities between you and your character?

Eric: Fortunately, no. But it did get me interested in reading and learning more about serial killers. Although repellent, they're often very brilliant, bold and fearless people. Evil characters like that offer me a great opportunity to be creative.

Fitz: Does that mean you're really a super nice guy?

Celebrity Fitzness Report: Eric Stoltz(click thumbnails to view gallery)

Eric: Not really. I'm just average nice, but definitely not like my character on Grey's.

Fitz: You look like a pretty fit guy. Do you work out?

Eric: I do, but not because I'm trying to get big. I'm just trying to stay healthy and in shape. I do cardio and strength training on alternating days.

Fitz: Would you gain or lose lots of weight for a role?

Eric: In a heartbeat! I once saw Laurence Fishburne, who had recently gained about 40 pounds of muscle, and I asked him about it. He told me that he'd been paid to work out for two hours a day and I thought, "sign me up!" I have had to lose 10 to 20 pounds before quite quickly for a role.

Fitz: How'd you do it?

Eric: I just stopped eating desserts and starchy carbs. Eat less, exercise more.

Fitz: Amazing -- people think I'm crazy when I tell them that. So simple, isn't it! What are your regular eating habits like?

Eric: Well I'm a vegetarian. I don't eat flesh.

Fitz: What's your favorite healthy food?

Eric: Pasta with eggplant and mushrooms.

Fitz: Have a favorite not-so-healthy food?

Eric: Pizza.

Fitz: If you were on Death's Row like your character on Grey's Anatomy, would pizza be your last meal?

Eric: Oh no! I'd have a a smorgasbord of everything I liked.

Fitz: Do you know there's a budget of about $40 for last meals?

Eric: No way! I can't believe we pay millions to care for these people and then have a tight budget for the last meal! Wow!

Fitz: I guess tax payers don't want to pay for a fancy send-off. So you've been in so many great films, do you have a favorite role?

Eric: No. I rarely or never look back. Maybe some day, I will. But not now.

Fitz: And usually I ask what my guest's advice is for becoming more fit, but I'd rather ask you your advice on achieving great success.

Eric: Never listen to anyone's advice! Follow your own voice, floss more, read more books and exercise.

Fitz: Thanks so much for the very fun and slightly silly interview, Eric. I kind of feel like it should have taken place at a sports bar over a (light) beer. Maybe next time!