A. J. Jacobs

The key to making healthy decisions is to respect your future self. Honor him or her. Treat him or her like you would treat a friend or a loved one. A Stanford study showed that those who saw a photo of their future self made smarter financial decisions.

I tried the paleo diet, which is the caveman diet - lots of meat. And I tried the calorie restriction diet: The idea is that if you eat very, very little - if you're on the verge of starvation, you will live a very long time, whether or not you want to, of course.

My goal? To test out every diet and exercise regimen on planet earth and figure out which work best. I sweated, I cooked, I learned to pole dance. In the end, I lost weight, lowered my cholesterol and doubled my energy level. I feel better than I ever have.