This is all off topic from the OP..........
Actually when you look into the hard and arduous life that our forefathers had and look into the diets, carbohydrates are plentiful. So the statement
It was a hard and arduous life fuelled mainly by fats and protein, not sugar.r
is pretty wrong. Carbohydrates from dried fruits, beans and peas were plentiful in their diets when available. The 1588 Royal Navy sailors were given a pound of hard tack a day and a gallon of beer. Both high in carbs.
When reading the wikipedia article, links in it and other history that give the diets of our rugged forefathers, they seemed to even use in great amounts what ever form of sugar was readily available. Honey, syrups from various trees and plants. You seldom find diets of the explorers using exclusively fats and proteins unless that was all they had becuase they were in barren places, like the Arctic or Antarctic. While in it's purist form, pemmican, which is a Native American creation, was mostly fat and protein, even the Native Americans would mix in whatever carbohydrates were around locally when it was prepared for a meal.