Happened to come across a study of meat eaters (Inuit I think) that even when on all meat diet they where not in ketosis. Apparently raw meat contains enough clycogen and that together with certain amino acids in protein mean enough glucose for their diet not being ketogenic.I eat nothing but meat organs brain eggs ect for a over a year no carbs no fibre as a experiment
Also apparently early travelers where much more interested in hunting and the vegetable gathering of women kind of got tossed aside. I find it totally unbelievable that people who had access, even seasonally, to berries and edible palnts would not utilize them.