the only human population that is provably subsisting on a meat diet are the Inuit and they like all other artic meat eaters,dont eat a lot of the meat,its the fat that is needed most,to the point that even when starving,a creature will not eat seal meat,if the hide and fat layer are gone as there is a higher energy penalty in eating frozen meat than can be recoverd. Meat was important,but all of the archiological evidence points to it bieng only a small portion of total diet,BUT,there was no replacement for hides,and the siniews used to sew them,especialy into foot wear its a rabbit hole I will resist disertating now