Age: 12

Perhaps you've wondered why your empanadas are now less gloriously coronary-inducing. Or why Chili's constantly bums you out by displaying calorie counts. Thanks to a diet of Cool Ranch Doritos, a sedentary lifestyle, and generally absent parenting, 9 million American kids are overweight. By 2010, half of the children in the Americas will be obese, according to a recent study. The child-obesity epidemic is the country's greatest health risk. And one of the cause's leading champions is none other than former McDonald's aficionado William Jefferson Clinton. "Something like this could easily collapse our nation if we don't act now," he told a national fitness conference. It turns out that allowing vending machines stocked with junk food into public elementary schools wasn't such a hot idea. Neither was letting the kids play video games all day (better get the Wii Fit!). Meanwhile, the recent statutes banning trans fats in New York City, Philadelphia, and California—with more certain to come—are a reminder that kids aren't the only ones who need to be treated like children.

21. JOEL OSTEEN, PASTOR, LAKEWOOD CHURCH >>