A. J. Jacobs

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.

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.

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.