Here's an idea. Let's get a large proportion of our calories from inefficient animal sources. Then if there is a widespread crop failure we can eat the breeding stock and then the animal feed.
That's generally what happens in Africa. It doesn't work as well in North America because consumers here are too rich to switch to barley and oats when wheat is expensive.
Yes, ethanol is the American equivalent. If we ever have a food shortage due to widespread extreme weather or similar, the president can nix the ethanol mandate to eliminate the food shortage.
The world does not have caloric food insecurity. We might be insecure in terms of specific nutrients or specific foods, but the modern world is not insecure in terms of human food calories.
That's generally what happens in Africa. It doesn't work as well in North America because consumers here are too rich to switch to barley and oats when wheat is expensive.