Eating for basic health and fitness is simple. Seriously, people. Just cook with a high variety of whole foods, emphasis on grains and produce. And eat five perfectly planned small meals a day—not three. Oh, and try to memorize the glycemic index of every enticing product in the grocery store. Even better, hire a personal shopper and a live-in chef ... Not the world you're living in? Here's another way to simplify: Read our comprehensive guide to performance nutrition and follow the straightforward rules. We guarantee you'll feel—and play—better. Or we'll eat our words.