Good point. There's no way to feed anywhere near our present population an omnivorous diet with wild stocks, but, morality aside, the most efficient and least expensive way to feed six billion would be to adopt a primarily vegetarian diet.
Meat is rarely an economically efficient food, as it takes ten or fifteen Kilos of grain, fish meal, &c to produce a kilo of commercial meat.
Better to treat the meat as a luxury item and just consume the grain.
Grains and beans are concentrated, easily transported and need no refrigeration or special preservation, plus, a given population could be fed on much less acrerage if half the grain didn't go to meat production.
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