Earlier quoted context omitted.
As opposed to other externally-caused problems like natural disasters, beating eaten by lions, etc. I would guess that a large chunk of human history was dominated by these problems.
Or just hunger in general. Before the agriculture revolution starvation was the primary cause of human death.
I know a couple books[1] that suggest life prior to the agricultural revolution wasn't nearly as famine-stricken as we tend to think it was. These books claim hunter gatherers were quite proficient at finding enough sustenance.
Obviously starvation was still possible and likely, but was it the primary cause of death? Is there some more evidence that humans were suffering from starvation before agriculture? Wouldn't populations thin out and stabilize accordingly if starvation was such a problem?
[1] - _Sapiens: A Brief History of Humankind_ and _Sex at Dawn_