Andrew Weil, MD
Clinical professor of medicine, founder and director of the Program in Integrative Medicine, University of Arizona, Tucson

"I have at various times tried diets to lose weight, and I'm absolutely convinced that they're not the way to go. Instead I think that you have to have a solid lifestyle and a formula that works for you. I generally follow a Mediterranean diet. I like sweets but limit my intake to the occasional piece of dark chocolate or scoop of sorbet and use them as rewards—if I've had a good exercise session or done a good bit of writing, for example. The biggest challenge is that I'm on the road a lot, and I tend to eat things I wouldn't if I were at home. So I've learned not to finish everything on my plate and to spend more time in the company of people who have the same kind of eating and exercise habits as I do. And when I'm home, I work with a personal trainer two or three days a week, do a little yoga, some cardio on an elliptical machine, and weight training."