PASADENA, Calif. — Mehmet Oz — better known as Dr. Oz — made his TV mentor a promise when he launched his own show.

And when you make a promise to Oprah Winfrey, you'd better keep it.

"This is the promise I gave Ms. Winfrey when I walked off the stage ... I will always make her proud, and I will make you proud, as well," Oz told TV critics.

After five years as a frequent guest on "Oprah," Oz now hosts his own syndicated daytime show.

(In Utah, "Dr. Oz" can be seen weekdays at 9 a.m. on KSTU-Ch. 13.)

Oz brings the same infectious enthusiasm that made him a favorite on "Oprah." A renowned heart surgeon, he has the natural ability to communicate with an audience.

By his own description, he devoted his life to academic medicine. He was a full professor at Columbia University before he turned 40, performing 450-500 open-heart procedures a year.

"It was a lot of fun," he said. "So what is it that took me from there to this, where I'm trying to talk about this stuff pretty graphically at times but always authentically and honestly in front of the public?"

He said it all came down to "one big insight." He would sit in his office, "day in and day out, and just try to understand" his patients. He would talk to people he "was about to cut open and recite to them the basic things they could have done differently to avoid that."

"And every single time their eyes would open like a deer in the headlights, and it would be an epiphany. 'Oh, my goodness. I could have done that? I didn't realize. Is that what fiber is?' And these sort of very basic insights that we knew could change American health ... weren't sinking through."

And that, he believes, is a flaw in the medical system.

"I began to appreciate that the reason America wasn't getting the message is because we're not giving it to them," Oz said. "We hadn't expressed it in the way that motivated them to change.

"So I embarked on this path about five years ago ... and attended Oprah University."

His on-air appearances on Winfrey's talk show gave him "three basic insights."

First, "people do not change because they know facts. We have, I think, the best educated populace ever ... but we're not acting on it because true action only happens when you take that knowledge ... and you put it down in your heart, where you have this visceral awareness of why it matters. And then people begin to get motivated to change their lives."