Slashing calories drastically can extend life span by a remarkable 30 percent—at least in flies, mice and monkeys. So does caloric restriction work in humans? A long-term study in monkeys suggests yes, but it’s a tough diet to embrace. Instead, a more selective change—avoiding meat—may add years to your life. Thomas Perls, M.D., founder and director of Boston University’s New England Centenarian Study, the largest study of long-lived people and their families, puts the veggie advantage at six years. In addition to saturated fat and cholesterol, red meat contains iron—and iron promotes the production of free radicals, highly reactive molecular fragments that speed cellular aging. So instead of slashing calories, how about eating less meat and more veggies? Bye-bye burgers, hello vegetarian chili.