[retrac]

Something approximating intermittent fasting, was probably an extremely common condition for humans to experience, until the development of agriculture.

In a mobile culture without access to lots of salt, there are few ways to preserve food. You eat what you find as you find it, as much as you can. Then you go hungry until you find the next big score. Hunters may go many days or weeks between large kills or a group reaches a more promising foraging ground, everyone scraping by on minimal nutrition like dried jerky and plants collected on the move. But doing that for a few weeks, or even months, is just fine, if everyone was well-fed at the start, anyway.