In 1900, the American diet consisted almost exclusively of animal fats with minimal olive oil, and chronic illness rates were very low.

“people were eating exclusively tallow which is rendered b fat or lard and the majority of pigs in 1900 were probably fed way better diets than their fed today the majority pigs today get corn and soy so we had animal fats which were much probably better for humans and they were essentially a hundred percent of the human diet of fats was animal fat maybe a little bit of olive oil but not even a whole lot in 1900 and so you're looking at butter tallow and lard as the main fats in the human diet and the rates of chronic illness were very low diabetes very low heart attacks very low cancer much lower”