Bananas don't have very many calories for their volume - somewhere between 80 and 200 depending on who you source for nutrition data. Same for grapes, apples, etc. There are only a few fruits that are really concentrated without processing.
Similarly, most meats in the wild are fit and lean, and you don't get concentrated fats(butter, cheese, cooking oils, etc.) either, leaving nuts as the largest likely fat source.
That doesn't mean that our new food sources are invalid, but one has to be aware that they're recent inventions, evolutionarily speaking, and deserve "occasional" use vs. "staple" status. Which is unfortunate considering that almost everything manufactured involves a concentration - "vegetable oil" (mostly soy and corn) appears all over, processed grain products are commonplace, and most of the items not using the first two are dosed with some combination of dairy fat, salt, and sugar. Between just those few ingredients, you can find the stimulating factors of almost everything on the market.
Thanks chipsy, I think you answered the question perfectly =)
To expand, bananas may be relatively high sugar/energy compared to other natural foods (green vegetables), but they cannot compare with the super concentrated foods we have created such as Twinkies =)
Similarly, most meats in the wild are fit and lean, and you don't get concentrated fats(butter, cheese, cooking oils, etc.) either, leaving nuts as the largest likely fat source.
That doesn't mean that our new food sources are invalid, but one has to be aware that they're recent inventions, evolutionarily speaking, and deserve "occasional" use vs. "staple" status. Which is unfortunate considering that almost everything manufactured involves a concentration - "vegetable oil" (mostly soy and corn) appears all over, processed grain products are commonplace, and most of the items not using the first two are dosed with some combination of dairy fat, salt, and sugar. Between just those few ingredients, you can find the stimulating factors of almost everything on the market.