Omnivore by necessity if nothing else. Humankind is a very successful and adaptable species.
I agree in the potential for a dumming down effect in certain carbohydrates especially with grains. I have heard mention in my travels through the world of historical literature that hunters/gathers actually believe man made foods where inferior and faught against the practices of sod busting and growing crops, they believed ,through experience, that crops like corn actually had an opiate effect creating a lack of energy needed to pursue game and made a warrior lazy and ineffectual. Through my own experiences a tend to agree !