The World Health Organization’s somewhat startling finding this week, that processed meats can be carcinogenic, has suddenly brought national dietary policy into sharp focus. Although the headline is an unsettling one, it is nonetheless altogether timely because of what is going on at this moment at the United States Department of Agriculture.

Right now, the folks at the USDA are deciding what Americans should and should not be eating for the next five years. And at the center of the debate is a very significant policy issue: sustainability.

In the latest development at USDA, which will significantly impact American diets, is the decision this month to exclude sustainability as part of its national dietary guidelines and to prioritize only “nutritional and dietary information and guidelines … based on the preponderance of the scientific and medical knowledge.” This is unfortunate. Nutrition and sustainability are inseparable.

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The USDA’s own Dietary Guidelines Advisory Committee, made up of federally appointed health experts, recommended an increase in plant-based diets earlier this year based on both nutritional and sustainability concerns.

The USDA should follow the advice of their advisers. What should drive our nation’s dietary priorities must be good for both the American people and the planet — otherwise there’s no way to sustain it. And there is no question that a plant-based diet is key to sustainability and our survival. “There is no question that a plant-based diet is key to sustainability and our survival.”

Take a look at the evidence. On the production front we know that a unit of beef protein contributes 150 times more greenhouse gas (GHG) emissions than a unit of soy protein. Beef production also requires nearly 30 times more grazing land than pork or chicken production. That’s a whopper of a difference. Pork and chicken also have a heavy carbon footprint, coming in at 20 to 25 times heavier in GHGs than soy.

But it’s not just what’s being farmed that impacts us all, it’s how products are being farmed. In comparison to conventional farming methods, organic farming produces gains in resource management and allocation. In fact, organic agriculture captures significantly more carbon than non-organic and industrial-scale farming, which are often much more water and resource intensive.

By avoiding pesticides, herbicides, hormones and genetic engineering, organic farming’s health and environmental benefits are also clear. Organic food is six times less likely to contain pesticide residues than food produced through conventional farming methods. Additionally, organic food prohibits the use of GMOs, the full environmental and health impacts of which are not fully understood.

Add to this fact that adding more plant-based foods to one’s diet is much more economical, which is a critical consideration for many American shoppers and families with a tight food budget, and it becomes clear why nutrition and sustainability are inseparable.

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Plant-based proteins, such as beans and grains, are often the least expensive foods available and produce a smaller carbon footprint than meat alternatives. Nationally, investing in organic agriculture means reducing costs associated with clean-up efforts in polluted water and soil from pesticides.

As our population continues to grow (the U.S. has one of the fastest population growth rates in the developed world), we must think creatively and courageously about more sustainable diets and long-term food security. By 2050, we’ll need to increase food production by 70% to feed 9.7 billion people, according to the UN.

At those rates, we simply do not have sufficient energy and water resources for a diet heavy in animal protein. The Advisory Committee points another path forward, and it’s one we must adopt soon. The health of this country, and its heartland, is at stake.

Matt Cartwright represents Pennsylvania’s 17th congressional district and serves on the House Natural Resources Committee. Michael Shank, Ph.D., is a professor at George Mason University’s School for Conflict Analysis and Resolution.