The longest lived community in the 'anglo' world are the seventh day adventists in California.
They don't do anything weird like starving themselves, although what they do was seen as weird 100 years ago when they started doing it.
They actually invented the idea of cereals for breakfast, with the guy who invented Corn Flakes, Kellog, being a Californian seventh day adventist - and in Australia they run the sanitarium health food company that makes many of our most popular cereals including weet bix.
Basically, they don't drink, don't smoke, eat vegetarian diet with a strong emphasis on nuts and grains.
With all the efforts they go to, their average life span is less than a decade longer than the rest of us, but i live near a community of seventh day adventists in NSW that was started in the 1890s, and they usually stay fit and robust well into their 60s or 70s, so they have a good quality of life.