That too is another point of contention, and that too has very little evidence to support it. With the Bellevue all-meat experiment again, can we conclude that "it's very important to eat as much of the animal as we can"? No, but we can conclude that if we did like they did, we'd be just fine. So, mostly fat, mostly muscle meat, and little of anything else.

Stefansson relates the anecdote of a hunt by a native hunter, where the hunter took the back fat and the hide, discarded the rest, because he just didn't have the means or the time to take the entire animal with him, i.e. he took the essential parts of the animal. Or for example, that the lean was given to the sled dogs, while humans ate the rest, primarily the fat, and in the event of a famine, the humans ate everything, then they ate the dogs.

Context is important. In abundance, why would we eat inferior food? No reason, we have ample superior food. During famine, inferior foods are eaten, not because it's preferred, but because they're starving. Here, it's the idea of abundance foods and starvation foods. Which part of the animal would they have eaten first, if they had been starving for a while? The preferred parts. What parts would those be? The same as if they'd have abundant game to hunt. OK, there's meat and potatoes on your plate, which one do you eat completely, which one do you likely waste if you're full half-way through? Meat first, potatoes go to waste. If you got just enough to buy either meat or potatoes, which one do you buy? Meat, of course. OK, it's between meat and potatoes here, but make it between meat and tripe, meat and liver, meat and kidneys. Now let's say you're rich and you can buy all the food you'll ever want. Why would you buy potatoes, or liver, or whatever else that you don't prefer? For me, it's Angus rib steak all the time. Nothing else even comes close.