Humans have historically had high fat/high carbohydrate diets. There was a book called the clash of civilisations( Really interesting read if you can get around it) which outlined some of the history of farming. I also have an ag degree so I was quite interested in the agricultural history in this book
But apparently the first grain crops were produced in Egypt in a fertile area on the river called the fertile crescent. The first crops were wheat oats ect. When the first crops were produced humans started moving out of of tribes and moved into communties. Other places in the world a similar thing happened. European communites may have taken some of the technology from Africa and started producing crops. Some In Preamercian america, American Indians down near the mexican border started producing maize crops, native Paupa New Guineans started producing Taro. Asiatic countries started mass producing rice.
On the other side of the earth in Australia, aboriginies continued to live off the land and did not get around to producing carbohydrate crops. The only commercial carbohydrate crop that has ever come out of Australia is Macadaemia nuts. It is believed that not producing crops is why the aboriginals remained unchanged in terms of advancement and technology. Just thought that might interest ya.
