Go vegan, save the world? Study highlights benefits of eating more plants

The United States could feed 350 million more people — twice the current population — if animal-based foods were swapped for plant-based foods, according to a new study.

In effect, the research suggests that major shifts toward plant-based — read: vegan — diets could be crucial to address increasing food demand for the growing population, while also working to cut other forms of food waste.

Four researchers from the U.S. and abroad published their paper in a National Academy of Sciences journal last week. A University of Wisconsin-Madison professor edited it.

The study focuses on the idea of opportunity cost, a concept more likely to conjure thoughts of economics than agriculture.

Researchers use the phrase "opportunity food loss" to describe "hidden food that can be recovered via changes in diets." This definition of food loss focuses on trade-offs.

Think of it like this: an acre of cropland could be used to produce hay to feed cattle, or to grow plants for human consumption. Most nutrients are, in effect, lost during the process of turning feed to meat or dairy products for humans to eat.

The study included five primary categories of animal-based products: beef, pork, dairy, poultry and eggs. Researchers identified beef as having the greatest opportunity food loss among the five — 96 percent of protein is lost in converting feed into beef when compared to a plant replacement product.

In other words, food is much more efficient when it goes straight to humans rather than passing through a cow. Eggs, for example, are lower on the spectrum, with a 40 percent opportunity food loss.

A growing population demands changes in land use

It's an issue of how we allocate land, the paper says.

"Replacing animal-based items with more resource-efficient plant alternatives will increase food availability by permitting reallocation of production resources from feed to human food."

The study doesn't outright advocate for all Americans to adopt vegan lifestyles; rather, it presents just how much of the country's agricultural land allocated to feeding animals instead of directly feeding people.

The researchers' analysis finds that "replacing milk and beef in the United States with plant-based alternatives liberates almost 700 million pastureland acres for wilderness preservation" while reversing the environmental harm caused by overgrazing.

The authors advocate for policymakers to pursue a two-pronged approach: targeting supply chain issues that lead to food being wasted or going bad, and reducing the "hidden" food waste associated with diets that are heavy on animal-based products.

Challenges abound to the food system in the U.S. and internationally: Exploding populations are creating food demand the world has never before seen.

A warming climate is making harvests less predictable, plus widespread droughts and coastal flooding threaten farmland and could displace communities around the globe.

To make sure all people have access to food amid these changes, the researchers say it will be crucial to address all the ways food is lost.

"Together, waste reduction and dietary shifts offer substantial food availability gains."