Do your own research if you want statistics. Fact is, people who stuff themselves, smoke, don't exercise, etc. become too sick to work a lot sooner than people who take care of themselves. They may spend about the same number of years not working, and receiving a lot of medical care, but that's after fewer years of working. Do the math.
Proof?
"Do your own research if you want statistics. Fact is,..."
If it is a fact, it should be easy enough for you to prove. Why not provide the data to support your claim?