Black bears attack humans on a regular basis, but I don’t think they kill them very often, as opposed to grizzlies (often as a percentage of attacks).

I was asking more about the diet, not about the threat to an individual human in an attack (which is substantially higher for a grizzly), but the two topics are related. My understanding is that grizzlies will attack and kill large game (including humans), which is something black bears don’t do.