We are all so stressed in this country!...lack of sleep, poor diet, lack of exercise, not to mention the stress that samurai talks about.....is aging us all very quickly, not to mention lowering our immune systems....When will companies and schools get it???? healthy employees/students are happy, productive, loyal employees/students.....

At Pepsi, you were emotionally docked for using all vacation / holiday time entitled to you, if you were in management.  Needless to say, I was not always in good standing because I actually took my weekends off.  If you were arriving to work later than 7:30a.m. and leaving the office any earlier than 5:30p.m. you were viewed as a "goof off".  You should see the aging that occurs across the board when people live on Diet Pepsi, whatever is in the vending machine, alcohol, and the drive to "win". 
I did my indentured servitude.  I look a lot younger now. 
Sleep is everything.

Sleep is definitely important.  I agree that shift work or night shift work messes with your circadian rhythms and I believe it shortens your life.  My dad worked night shift all his life from age 16 on and was diagnosed with colon cancer less than 3 months after he retired.   He died 3 weeks after his 65th birthday.  I am sure that his shift work contributed to it.