Most humans are vulnerable to T2

[skb]

Scientists have found that insulin has met an evolutionary cul-de-sac, limiting its ability to adapt to obesity and thereby rendering most people vulnerable to Type 2 diabetes.

Article

[Grammabear]

I wish the article would have elaborated about how mankind has arrived at this cul-de-sac of humans being disposed to T2.  I have a much younger brother who was just prescribed Metformin and he eats a lot of junk food.  He claims his doctor did not tell him "you have diabetes", nor did his doctor advise him to change his lifestyle.  What about the massive popularity, in this country anyway, of fast food?  What part does it play in this problem?