I'm 67, probably drink too much (anything at all appears to be 'too much' these days') am not obese and walk every day as well as singing and being busy. Not my lifestyle that gave me arthritis. Until being diagnosed with asthma earlier this year (all that pollen started lots of people off) I have happily written 'none' next to the 'medication' boxes on forms most of my life.
OH is 83 and apart from a heart problem (inherited from his mother and his son had an early heart attack too; he's thin as a rake and walks miles a day with the dog) is also healthy (odd brush with skin cancer). He's certainly not diabetic and walks the dog a minimum of 2 miles twice a day. (Proper poorly at the moment with the lurgy though.)
Suspect that it is a lazy lifestyle amongst the younger generations that is causing this. Compulsory sports in schools would help - and I mean sports not the excuse for a sports day I helped with at a 98% Asian girl's school in Bradford when they went the rounds in the gym of activities such as darts and catching a ball. I was in charge of bean-bag throwing. These girls were 13/14 and, yes, that comprised the whole of their 'Sports Day'. This was about 1999.