The evidence is simply overwhelming–healthy choices in eating and activity are the most powerful predictors of longer life and greater health. So says this Washington Post compendium of study results on how healthy lifestyles prolong life.
This doesn’t, of course, explain why so-and-so’s grandparents both lived happily to 90 while consuming a diet rich in pasta (it had garlic in the sauce, sure), cheese and wine all their lives, and not exercising to speak of. It doesn’t explain the Russian octogenarian who subsisted largely on meat, potatoes and vodka. And it doesn’t explain the guy who runs regularly, eats semi-vegetarian, avoids sugar, salt and fat like the plague, and ends up having a second heart attack followed by multiple bypass surgery.
So take it all with a grain of salt (okay, salt substitute if you must) and choose wisely as often as you can. Life is too short–usually no matter where you end it–to be beating yourself up more than necessary.