>Another reason people starve is economics and market forces. The market decides it wants to use up more water and grain to feed cows. That grain and water is now not available for purchase as human food. That means it is more scarce on the human-feeding market. Scarcity drives up prices. So livestock feed makes grain more expensive, making it harder to purchase, for people to eat.

None of these are logistics, energy supply, or war. The paper is specifically talking about increasing efficiency in food production, the originally commenter is saying that efficiency of production is not the main driver for undernourishment and your comment doesn't address that.

Something doesn't have to be the main driver to still have an impact on the problem. Increasing food production efficiency would have a marked impact on the problem, without requiring you to to figure out how to end war or "fix" energy or logistics.