Such and interesting, and
perennial, discussion. I think so many of these answers, as always, depend on where you are, what the history and resources of a given place are. It's a slightly abstract question (despite the original intent to get
concrete examples), because all of us live in a world where industrial supports are so deeply embedded in our habits that it's almost impossible to not use them in some capacity--especially the ones that work so well (like pvc hoophouses!). But we feel like we are building *resiliency* and skills, so that if we were ever truly pushed to *need* to do without the industrial support system, we could survive.
My implication here is that humans are extremely adaptable, and as all the examples given so far make clear, we do a wide variety of things to get our calories as necessary... bugs, anyone? For us, wild foods provide the protein-and-calorie dense foods that
wood supplement the potatoes. So our half-acre grows significant (but not the total required)
root crops for starch calories, and we also grow abundant greens and other veggies (potentially year-round in the PNW, but we're not there yet, personally) for the varied nutrients we need for health. We fish and crab, and I'm trying to increase our bean production. But this is all to basically match how my colonizing European ancestors ate and survived on the homestead (and who also still supplemented with flour, sugar, etc). But if we were truly going to try for a
permaculture diet, our real calories would come from a lot more meat than we generally like to eat:
deer,
rabbits, quail, etc are plentiful wild animals around here, and they're not usually seen as food.
But I often wonder if this is where the population factor comes into play. I think hub and I could/would survive pretty well on the resources available to us here. But if we were competing with everyone around us? Then the question of how much
land each does our diet require and how many of us are there in a given place really rears its head...