> An adult sleeping only 6.75 hours a night would be predicted to live only to their early 60s without medical intervention.

I wonder if this controls for other lifestyle factors. Eating a lot before bed makes me sleepier and I could go 7-8 hours a night. Small dinner several hours before bed results in about 6 hours. No alarm clock, that's just how much I need. I find it hard to believe that I'm shortening my lifespan by eating less at night.