Something interesting to note, indigenous Australians also had a very high protein diet, consisting mainly of meat, with some yams, seeds and fruits. One of the ways in which they obtained adequate vitamin C, was from eating the intestinal contents of grass eating animals, such as kangaroos. Not all tribal groups did this, but many desert people did, because the vegetable content of their diet was so low.
Diabetes, kidney disease and heart disease are epidemic in indigenous Australians, this has been the case since a western diet, high in simple carbs and Sugar has been adopted.