Study: To feed four billion more, skip eggs, meat, and milk

In fact, “we find that doing a complete radical shift away from grain-fed animals, and stop producing biofuels, that you can increase calorie availability enough for 4 billion people,” Emily Cassidy, a researcher at the Institute on the Environment at the University of Minnesota, told NBC News.

She and colleagues examined 41 major crops grown around the world, which account for more than 90 percent of global crop production, to find out how much food is being produced and how it is being used.

They found that 36 percent of the calories produced are used for animal feed. Of those, 12 percent wend their way to the human diet as meat and animal products. Another 4 percent of human-edible calories are used to produce biofuels.