I love food and I’m really bad at dieting. I’m just going to put that out there. I mean, I can do it for awhile, but the craving and the crankiness generally win out, and the pounds come back.

Yet there are thousands of people around the world who are eating well and living beyond their centennial birthdays. They don’t belong to a gym, count calories, or spring for that big box of Weight Watchers frozen meals at Costco. They even eat cake sometimes. And National Geographic fellow Dan Buettner knows their secret.

Buettner has spent years studying people in what he calls “longevity hot spots” around the world, from Okinawa, Ikaria, and Sardinia to Costa Rica and Loma Linda, California—home to a