Oprah and Dr. Oz
Photo: Ruven Afanador
I met Dr. Mehmet Oz in 2003—the year he and his wife, Lisa, created a medical series called Second Opinion with Dr. Oz for the Discovery Channel. My friend Gayle was so intrigued by him that she encouraged me to be his first guest. Lucky for me, Gayle isn't just persuasive—she's perceptive. The day of the taping, I immediately recognized what she'd sensed: a cardiac surgeon who cared as much about transforming people's lives as he did about fixing their hearts.

The following year, the doctor and I swapped couches when I invited him to be a guest on my show. It would be the first of 62 visits. Viewers came to embrace the Cleveland-born, Harvard- and University of Pennsylvania–educated Dr. Oz as "America's doctor"—the purple-gloved teacher who could talk frankly about everything from orgasms to the ideal color (brown with a hint of gold) and shape (S) of poop. Over the years, he educated us, gave us helpful advice, and saved countless lives—from heart attack victims who, thanks to him, recognized their symptoms in time...to a cancer patient who, mindful of his warnings about medical mistakes, realized that she still had the tumor her surgeon was supposed to have removed. He's the reason I started wearing lower heels (my bunions are eternally grateful), and he taught me everything I know about the omentum.

In 2009 Oz went from guest back to host with the launch of The Dr. Oz Show—and took home an Emmy the very first year. Last fall he began the show's third season with a big announcement. "Every person has the right to look and feel like a million bucks," he told his audience, "so we decided we would make a million dollars available as motivation." In a challenge called Transformation Nation: Million Dollar You, Dr. Oz, in partnership with Weight Watchers, is encouraging Americans to take practical steps to overhaul their health; the winner of the challenge (and the money) will be announced on his show in May.

It's enough to keep anyone more than busy—and it's only one part of what Dr. Oz has on his plate. He and Lisa, who've been married 26 years, are the parents of four children (Daphne, Arabella, Zoe, and Oliver)—the youngest two of whom still live at home. He loves to travel, especially to Turkey, where he spent much of his childhood and where his family's roots are. And every Thursday he still performs heart surgery at New York–Presbyterian Hospital/Columbia University Medical Center.

How does he do it all? Turns out, he's not exactly sure himself. We talked about that—and about food, fame, and the ups and downs of marriage—when we got together for a good healthy chat.

Next: Start reading Oprah's interview with Dr. Oz