A year and a half ago, Tunks maxed out the doctor's scale at 350 pounds--and vowed to lead a healthier lifestyle. As the father of two toddler boys, he says, "I needed more spring in my step to keep up with them." Now he's slimmer by 85 pounds--and by 12 pants sizes.

To battle the bulge, Tunks took a lowfat approach--a bagel with light cream cheese for breakfast, a Subway turkey sub, minus the cheese and mayo, for lunch, and a healthy dinner of fish and vegetables. He tries to curb the late-night snack attacks that plague chefs by eating before going to work in the kitchen. To help burn calories, he began working out at the Sports Club/LA, and he walks instead of taking cabs to and from his restaurants.

On average, Tunks lost a pound a week, but his weight loss recently plateaued. He says he'd like to lose another 25 pounds; to jump-start the process he's trying the South Beach diet. He lost eight pounds in the first 11 days, but he doesn't plan on making a life of it. "It's not natural to go to TenPenh and not eat rice or noodles," he says.