The underlying cause is genetic. You had it the day you were conceived. On the other hand, Type II diabetes is not a “disease” if you lead the correct lifestyle ~ which seems to include an almost exclusive fish, meat and low starch rootcrop diet, at the top of mountains, with miles and miles of walking, lots of other exercise, running with the dog-team, chasing reindeer, chasing wildabeast, hunting seal on Arctic pack-ice, and avoiding anything else except for tree nut oils.
I never said it was a 'disease' in the classical sense of it being pathogenically induced. You otherwise reinforced my point - if you have the genetic predisposition for it, the best way to combat it is thru diet and exercise. And it takes a pretty radical change in lifestyle to do it - most people would rather pop pills and live a more sedentary lifestyle. But, I'm not one to do that and cry 'woe is me' over it. I knuckled down and kicked it's ass. It'll always be there, lurking, and waiting to pounce if I let my guard down, so it's a lifelong commitment. But it's a commitment that'll affect how long that life
is.
