Kathy Freston

I missed a tuna-fish sandwich with mayo on toasted wheat bread more than anything. Six months after I went vegan, I snuck into a deli and took one home. And, of course, it wasn't nearly as good as I fantasized. It tasted, well, fishy.

Whole foods like grains and beans release their sugar very, very slowly because of the fiber in them, and they don't give you a sugar rush. They feed your cells as needed, and as a result, you have loads of stable energy that powers you through the day.