USDA, Virginia Tech explore a world without food animals

By Susan Kelly on 11/27/2017

What would happen if U.S. farmers stopped producing animals for food and Americans went vegan?

Noting some have called for a move toward veganism to address concerns about U.S. health, eating habits and climate change, researchers at USDA’s Agricultural Research Service and Virginia Tech set out to explore the nutritional and greenhouse gas impacts of removing animals from U.S. agriculture.

They found that a complete shift away from food animal production would present major challenges to meeting America’s nutritional needs. With no meat, milk, eggs, fish or cheese in the American diet, the U.S. population would not receive enough of several different essential dietary nutrients from the foods they eat, according to the study results.

“Different types of carefully balanced diets — vegan, vegetarian, omnivore — can meet a person’s needs and keep them healthy, but this study examined balancing the needs of the entire nation with the foods we could produce from plants alone. There’s a difference between what’s possible when feeding one person versus feeding everyone in the U.S.,” said ARS scientist Mary Beth Hall.

The findings were published in Proceedings of the National Academy of Science.

Eliminating food animals would increase deficiencies in calcium, vitamins A and B12 and some important fatty acids. Fatty acids help to reduce cardiovascular disease and improve cognitive function and vision in infants. Animal food products are the only available, non-supplemental sources of some fatty acids and vitamin B12.

A plant-only diet also would require individuals to eat more food and more daily calories to meet their nutritional needs because the available foods from plants are not as nutrient dense as foods from animals, the researchers said.

The scientists found that shifting land usage from food animal production to food crop production would increase the total U.S. food supply by 23 percent. Because much of that land is unsuitable for high-value crops, most of the additional food produced would include high-calorie crops like corn and soybeans.

They also determined that eliminating food animals from U.S. production would reduce greenhouse gas emissions, but not by the full 49 percent of agricultural emissions that animals currently contribute. Rather, greenhouse gas emissions from agriculture would drop by 28 percent without farmed animals because of increases associated with producing additional food crops and the use of more synthetic fertilizer to replace manure. That would represent a drop of only about 2.6 percent of total U.S. emissions.