I'm not naive when it comes to doctors' diets. I've seen M.D.s eat cookies in hospital cafeterias and gulp down sodas at medical conferences. One of my doctor friends sneaks corn dogs and fried dough at the beach. But even I was surprised when I sat down to dinner with a couple of physicians one night and watched them order the biggest steak platters on the menu. Here were two guys who presumably recognized the ills of dietary fat and clogged arteries, eating an overly rich, wildly caloric meal. Shouldn't they have known better?

On the whole, America's physicians are healthier than the people they take care of. Twenty-one percent of the population smokes; only 4 percent of docs do. And M.D.s are leaner, too. Forty-four percent of male doctors are overweight and 6 percent are obese, according to Harvard's Physicians' Health Study. The rest of America: 65 and 32 percent, respectively. We can all do better.

But doctors are the people we look to for guidance and advice about our health. If they're not making wise choices, what kind of message are they sending us? Studies show that physicians are more likely to counsel patients about good health habits when they're also following the rules. "You can't look a patient in the eye and talk to them about exercising, diet and weight loss if you yourself aren't a role model," says Dr. Ted Epperly, president of the American Academy of Family Physicians.

Dr. David Eisenberg, director of the Osher Research Center at Harvard Medical School, came up with a novel idea: teach doctors how to create "nutritious, yet delicious" meals so that they can, in turn, teach their patients. With diabetes, heart disease and cancer plaguing this nation, a nutritious diet is "as essential as any prescription drug or surgery," says Eisenberg, who developed a passion for cooking as a child when he spent weekends in his father's bakery. Last month some 300 health-care professionals, most of them physicians, gathered in Napa Valley to attend Eisenberg's brainchild, Healthy Kitchens, Healthy Lives, a collaboration between Harvard and the Culinary Institute of America. They listened to scientists talk about healthy carbs and phyto-nutrients. They received guidance on the basics—how to hold a knife, how to measure portion size. And they learned how to eat mindfully, savoring flavor, texture and taste.

Dr. Rajani LaRocca attended an earlier session in April and went home inspired. Plenty of LaRocca's patients at a community health center in Charlestown, Mass., want to lose weight, but too often they look for an easy out. "People come in and ask, 'Is there a pill?' " she says. A couple of weeks ago, LaRocca and her colleagues put on a healthy-cooking demonstration for their patients, teaching them that olive and canola oils are "good" fats—something many doctors still don't know, according to a survey of physicians published in Nutrition Journal. "You have to change the basic way you think about food," says LaRocca.

Medical professionals must change the way they think about themselves, too—and early on. Dr. Jo Marie Reilly, of the Keck School of Medicine of the University of Southern California, has seen the negative impact that doughnut-eating, sedentary young M.D.s can have on their clinic population. Patients will say, "This doctor is telling me to lose weight and exercise more, but look how he looks," Reilly says. Reilly's first-year med students must fill out a "physician wellness contract" stating their personal health goals. Yohualli Balderas-Medina, 23, committed to running regularly and maintaining close ties with friends and family, which can reduce stress and lead to better health outcomes. She's done both, and says she feels "healthy and motivated." A great beginning for a future doc and her patients.

© 2008