I got mine from junk food, and too much of it, but then again I ate about that a day. (Well maybe on a bad day, but if a bbq is a bad day......)
And when I stopped eating that, and lost a quarter of my body mass, I lost the diabetes with it.
So, I have no problem facing the fact I ate my way to diabetes, as that meant I could take the steps required to resolve it.
Mediterranean diet now, healthy non saturated fats, exercise, and fresh food.
So even if may not help the 20% who aren't obese, perhaps it can help the other 80%, and 4 out of 5 is a good enough starting point for me.