I'm a big admirer of Walter Willett's work. I think he's done some really important research. He and I agree on most things.

With everything that you can imagine at our fingertips, many of the social interactions that help tie people together in a community have faded away. Are communities traditionally built on relationships, trust and familiarity a thing of the past?

Think about it: Heart disease and diabetes, which account for more deaths in the U.S. and worldwide than everything else combined, are completely preventable by making comprehensive lifestyle changes. Without drugs or surgery.

One of the reasons my father ... became a dentist was so he could always be home for dinner and spend weekends with his family. At one point he had thought about being a musician, but he said, I'm not going to do that because I'd be on the road all the time and I wouldn't be with my family.

At a time when 20% of people in the US go to bed hungry each night and almost 50% of the world's population is malnourished, choosing to eat more plant-based foods and less red meat is better for all of us-ourselves, our loved ones, and our planet.

Love and intimacy are at the roots of what makes us sick and what makes us well, what causes sadness and what brings happiness, what makes us suffer and what leads to healing...I am not aware of any other factor in medicine- not diet, not smoking, not exercise, not stress, not genetics, not drugs, not surgery- that has a greater impact on our quality of life, incidence of illness and premature death from all causes.

I usually find that the process of discovery is more interesting than the answers.