Is the salt obtained from meat (as the primary diet) nutritionally sufficient?
Hunter-gatherers rarely if ever added salt to their foods, and studies of salt-free Yanomamo Indians have shown these indigenous people to maintain low blood pressures that do not increase with aging (Oliver et al, 1975).


--The paradoxical nature of hunter-gatherer diets: meat-based, yet non-atherogenic. European Journal of Clinical Nutrition (2002) 56, Suppl 1, S42–S52 (PDF link)

(The Yanomamo Indians were/are hunter-gatherers, but that doesn't necessarily mean their diet was mainly meat - plants and fruits are important components. However, meat is likely to be higher in salt than plants, so this just supports the general principle.)