DowrgiYou mention our ancestors: it depends how far back you want to go, if we go right back, then our ancestors would have been following a hunter-gatherer lifestyle and diet. This diet did not mean going for long periods of time without food, although that was always a risk, but through circumstance rather than choice. However, this kind of diet, as evidenced by contemporary hunter-gatherer societies’ lifestyles and diets, did mean a lot of variation, little to no excess, and small amounts frequently – obviously coupled with much more physical exercise than many modern, sedentary lifestyles entail.