This may sound surprising to most. It was surprising to me when I first read it. But on the front-cover flap of the Dr. William Dement’s book “The Promise of Sleep: A pioneer in sleep medicine explores the vital connection between health, happiness, and a good night’s sleep” (not sure why they make book titles so long), it says …
“Healthful sleep has been empirically proven to be the single most important factor in predicting longevity, more influential than diet, exercise, or heredity.”
At first I might think that diet comes first, second is exercise, and third is sleep. But that’s what the book says. I would have like to see the study, but didn’t see it. So I don’t know how valid that study is.
However, I do believe that most people under estimate the importance of sleep.