I’m talking about before we figured out we could grow vegetables and fruits. Early humans are often shown as being fit and in shape, yet our diet pretty much only consisted of meat. We were hunters. So why the hell were they so fit? I thought a healthy diet mattered more than just being active constantly?
I think it’s important to realize that almost everyone is plenty healthy at 30 years old assuming they haven’t grown enormously fat. Health decline is a more recent issue as people have lived long enough for organ failure/cancer to take over as the leading cause of death instead of malnourishment/injury.
A huge problem was teeth. Eating those old hard seeds and fruits plus grinding down greens wore away teeth. Once the teeth are gone, wild animals quickly suffer malnourishment and early humans would have had the same issue. Living to a ripe old age would require soft food, plentiful access to it, and not dying to infection. Only then would long term health be a real concern for our ancient ancestor.