But that's in terms of total agricultural output, under a scenario where you stop feeding a large portion of your crops to livestock, and where large amounts of food aren't wasted. The first line in the wiki article you link to mentions that roughly 1/6 of the planet is malnourished. The WFP says that ~6 million children die of malnutrition and hunger related diseases annually in developing countries. Meanwhile, the US feeds something like 90% of its soy, 80% of its corn and 70% of its other grain to livestock, much of which we kill for meat. This fact -- that the rich choose to consume luxury products with relatively large footprints in terms of limited resources, such as meat when the world's poorest are malnourished, or beer or consumer electronics when many have insufficient access to clean water -- makes me think that our future ability to sufficiently feed 9-10 billion people will be less a function our total agricultural resources, and more a function of the disparity between the rich and the poor.
As attractive as your logic sounds, it is wrong. If the rich world consumed fewer food resources, that would not mean the poor would eat more. There is not some fixed quantity of food that is distributed by some central zero-sum mechanism. Rather, malnourished people are malnourished because they live in areas with dysfunctional economies and governments. Producing food isn't the problem, distribution is.
I totally agree that the issue isn't producing food but rather distributing it process. I further agree that this isn't a strictly zero-sum mechanism.
But yeah, if rich people consumed fewer food resources, prices would drop, and some malnourished people who can't afford sufficient food now would be able to afford more. Blaming the problem on dysfunctional local economies and governments is facile way of absolving oneself of personal responsibility -- "My consumption of limited resources isn't the problem; it's corrupt governments. I can keep consuming however I like, comfortable in the knowledge that I'm not causing harm to anyone else". Yes, dysfunctional governments and economies in developing countries are part of the problem, and no matter what rich people do or do not consume, they probably won't help the hungry people in N. Korea by doing so. But there are plenty of places where that's not the case. The fact that the 2007-2008 food crisis did meaningfully impact a lot of people in developing countries should indicate that we are all connected to the same global food economy, and what we do with our agricultural resources in rich countries can and does impact the prices and availability in developing ones.
