From what I've read in Dr Julian Whitaker's book REVERSING DIABETES, and my own experience, statistics I've read and different articles I've seen over the years there is a definite predisposition towards getting diabetes from genetics, but it can be averted if we eat much less fats, and sugars.
I believe overloading the body with fats [meats,trans] and sugars will cause the way too much storage of fats in the cells, and when we age a bit the body can no longer take in more and we become resistant to the natural way a human being is supposed to deal with sugar conversion, in short we become allergic or rejection of insulin released occurs. Why we'd take more insulin when our own naturally-manufactured insulin is being rejected by our digestive systems seems off to me. It is necessary however, or we get really sick. Perhaps there is a precursor of insulin released by our pancreas that is converted improperly to utilize the intake of glucose.
Now that we are both confused, I know why I got diabetes. I was a confirmed carnivore. I especially loved pork. I can no longer digest it so I stay away from more than a bite or two of it. Now, of course I eat NO red meats, and don't let the advertising fool you pork is a 'red' meat. It's white color is fat; fat, f-a-t and more FAT, Pigs have fat inside each cell. My digestive system, as vulnerable as it is from Candidiasis just won't, it just quits on me. It wants to do that anyway from the IBS, I take heaps of Psyllium fiber and flax seed oil each day.
I know I'm repaying a debt of many years of eating abuse. My favorite meal a few decades back was nachos; tortilla chips, ground beef, Jalapeno peppers and mounds of cheese, None of which helped me be healthy. Before that I dined daily on fried Chicken. I can hardly believe I'm alive. especially since I just quit exercising.
But I am A-L-I-V-E and I'm doing so much better. For the last ten years I've felt myself going downhill rapidly, I hurt all over, I was getting fatter and fatter, all the muscle of my youth was replaced with lard. I was also rapidly losing strength, I used to be quite strong but got to where I was using handicapped aids to open jars, to grip, to hold things etc.