Keep in my mind that humans still frequently eat a variety of unprocessed grains. Corn, barley, oats, rice, quinoa, et cetera can (and often are) be ground into flour for baked/fried breads, but a bowl of rice and corn-on-the-cob would be hardly out of place on most people's dinners.

hi! while it's possible you'll get answers here, questions on early humans are worth x-posting to our sister sub /r/AskAnthropology