'Diets' That Promote Health (and Always Have)

The Mediterranean diet is believed to be responsible for the low rates of chronic heart disease in the 16 countries bordering the Mediterranean Sea.

And if you're watching your weight—and who isn't?—calories really do count. The key is replacing less healthful foods with healthier ones, not just adding tofu to your bologna sandwich or nuts to your sundae. As Pollan says, "Eat food. Not too much. Mostly plants." That doesn't mean eschewing all indulgences, but it does mean keeping an eye on day-to-day intake. "It's about the pattern over the long term," says Oldways' Gifford. "Do you think people in the Mediterranean get drunk after church on Sunday? Sure, they do! We're human, and you have to take the pressure off the pressure cooker."

Even with occasional excesses, adopting a sound dietary pattern may be both simpler and more wholesome than chasing down the latest superfood or nutritional supplement. "Finally, the field has come around to realize that it won't be a single nutrient," says Tucker. "We're back to old-fashioned advice: Eat a variety of good-quality whole foods. That's the way to stay optimally healthy."