You’ll meet a 94-year-old farmer and self-confessed "ladies man" in Costa Rica, a 102-year-old grandmother in Okinawa a 102-year-old Sardinian who hikes at least six miles a day, and others. By observing their lifestyles, Buettner's team has identified critical everyday choices.

Dan Buettner: Many Americans exercise too hard. The life expectancy of our species, for 99.9% of human history, was about 30 years. The fact that medicine has pushed life expectancy to age 78 doesn't mean our bodies were designed for three-quarters of a century of pounding. Muscles tear, joints wear out, backs go out. The world's longest-lived people tend to do regular, low intensity physical activity, like walking with friends, gardening and playing with their children. The key is to do something light every day.

I also think the trend toward isolation is a mistake. Drive down any American street at 9:00 pm and you can see the greenish glow of the television or the computer in people's window. We've become an increasingly isolated society. Fifteen years ago, the average American had three good friends. Now it's down to two. We know that isolation shaves good years off of your life. In The Blue Zones, I advocate reconnecting with your religious community and proactively building friendships with the right people.

Question: Is there something about the physical landscape that contributes to an area being a Blue Zone, or can people make their own personal Blue Zones, regardless of where they live?

Dan Buettner: Staying young and living long is mostly a function of your environment... and the good news is that to a great extent, we each have control over that environment. In the Blue Zones around the world, people live in places where walking is the main means of transportation, where the sun shines strong all year long so they get enough vitamin D; where they have established social norms that bring people together in supportive groups or clubs. The Blue Zones book shows you how to take about two hours and set up your home, your social life and your work place to help you get up to 10 more good years out of life (and look younger along the way!).

Question: Are Blue Zones about living longer, or living better?

Dan Buettner: Both. The same things that get you to a healthy 100 get you there better. The Blue Zones offers a completely different way to think about longevity and youth maintenance. If you look at the Power9—the common denominators of the longest-lived people—you see that they tend to put their families first, they belong to a faith-based community and they know their sense of purpose. All of these behaviors are associated with 3-6 years of life (which is better than any diet can promise) and they're good years. In other words, the same Blue Zone tenets that will help you get to a healthy age 90 will help ensure those years are vital and enriching.

Question: If considering all nine habits at once seems overwhelming, what's the first step someone could take toward living a more enriching, longer life?

Dan Buettner: The good news is that the Power9 is an a la carte menu: by no means do you have to do all nine to gain more good years out of life. In fact, do six of them and get about 90% of the benefit. The most important thing you can do is building your own Right Tribe. Which is to say, all of the world's longest-lived people were born into, or consciously chose to associate with, the right people. The Framingham Studies show us that if your three best friends are obese, there's a 50% better chance that you'll be obese. The reverse is true too. If you dine with people who eat healthy food, you're more likely to eat healthy food; if the friends you spend the most time with play a sport, you're more likely to join them. As your mother said, "You're known by the company you keep." You're also likely to resemble them.