history

One example I can think of that was pretty bad was during the Great Famine of 1315-1317, which coincided with the end of the Medieval Warm Period. Several bad harvests over those years devastated the people of Northern Europe a generation and a half before the coming of the Black Plague. Even the aristocracy, the people at the top of the feudal mode of production, had episodes in which they found food harder to come by. Anecdotally, the King of England himself, when taking up residence in a town, found it without enough food to feed his entire group of followers.

The very young were abandoned and sometimes the very old volunteered to starve themselves to spare the able-bodied. After the people exhausted their reserves of food, ate their seed grain, and slaughtered their draft animals, it's not hard to imagine at least some instances of cannibalizing the recently deceased, if stray animals could not be found. It was reported in the chronicles of the era.

Another I can think of off the top of my head is the Jamestown colony during it's early history, which was called the Starving Time. During the winter of 1609-1610, less than a fifth of the original 500 colonists were still there, and recent archeological findings show clear evidence of survival cannibalism.