The program tackles America's latest epidemic: obesity. Twenty-five percent of adults are clinically obese. Even more alarming, 20 percent of children are obese, and the number is rapidly increasing. Alan Alda visits with Dr. George Blackburn of the Center for the Study of Nutrition at Beth Israel Deaconess Medical Center in Boston. Blackburn and Alda explore society's obsession with diets that promise quick and painless results. Alda visits with the Arizona's Pima Indians who have the world's highest rate of obesity-related diabetes. For more than 10 years, the program has followed a long-term National Institutes of Health study that has yielded important information on the genetic basis of obesity. Many Native American leaders -- supported now by this research -- advocate a return to traditional diets in order to save not only their culture, but also their health. Alda heads into the desert with tribe elder Danny Lopez to collect wild foods and prepare a traditional Pima meal.