I think our ancestors wherever they were from had to sustain themselves on what they had available in their region. Mine sustained themselves in France on hunting deer, pheasant, doves and wild rabbit; domestic duck, goose and rabbit, eggs, mushrooms they had lots of farmed onions hanging up in an attic for the winter, wine. IDK what else... There probably was no cane sugar to be had back then in that area except for small amounts imported at high prices.
There is a very good reason why we shouldn't be eating marshmallows and why it would make us sick.