that is true, but the scalability is actually fairly reasonable. we know that only around half of the food crops we grow are used for human consumption. the rest is used as feed for livestock. not to mention that the majority of agricultural land, like 80 percent or something like that (i think), is allocated for livestock as well. whatever quantity of calories we obtain from meat consumption, we currently produce several times more than that in animal feed, so paradoxically if we stopped raising livestock, we might be able to feed more people that we currently do, and would have lots of extra land to grow stuff on. theoretically.