Eating every couple hours is not historically impossible. The gatherer end of the hunter-gatherer duo usually do not have to search far for food. You don't need to guess at this, we have records of how the !kung san lived and continue to live.

Besides, people get really hungry if they don't eat for long stretches between meals, what to do about that? Turns out if you have a couple pieces of fresh fruit, every couple hours, it will suppress the hunger and you also won't gain fat. This is because the body handles the sugar differently than more complex sugars, and also because fresh fruit is more filling than a calorically-equivalent ball of white rice. Our primate cousins like the chimps are mostly-frugivores too, by the by.