I don't know. How do you explain the evolution of our teeth which are better adapted for a herbivorous diet?
Nor are we particularly fast or strong so as to hunt very well or often...
I think the problem is the speed with which refined carbs are taken up by the body. Somewhat related to glycemic index.
My opinion is that we should trust our own bodies a bit more, listen to it and observe it. If a particular type of food makes you bloated or lethargic, avoid it. If you feel fresh and energetic after eating something, go for it.
I don't remember exactly who said it, I think it was Robert Lustig, but your quality of life and productivity is determined by how much energy you're using up so foods that promote energy expenditure are your friends.