You are right to point out carbs helped our survival. The modern USDA food pyramid tells us to eat 6-11 servings of grains per day, all the veggies we can stand, and plenty of fruits. That's an insane level of carbs, especially because most people tend to overdo "healthy" advice. If grains are good, I'll eat more! Our tragic obesity and diabetes epidemics are a direct result of bad advice from the USDA that filtered down through our schools, hospitals, doctors into our psyche. Now when you assert meat has nutrients, saturated fat isn't unhealthy, or the keto diet reverses diabetes and obesity--people stare back cross-eyed. We desperately need a new (published) food paradigm and it shouldn't be a pyramid.