When it comes to the food we eat, there’s practically no such thing as a “guilt-free” diet — practically any food, unless you grow it yourself without using excessive pesticides or water, comes with nutritional, environmental or ethical consequences.
But according to new research published last week in the Elementa journal, some diets fare far better than others when it comes to the important measure of how much agricultural land is required to produce the food they require.
Specifically, diets that contained less meat tended to be far less land-dependent and, therefore, held the potential to feed a larger population on a per-square-foot basis.
“A population eating less meat than we eat now would, generally, feed more people,” Christian Peters, Tufts University associate professor and the paper’s lead author, told The Huffington Post. He added, however, that’s only true to a certain point.
The paper, authored by a team of Tufts researchers, considered the land requirements — or “food-prints”— of 10 different diet scenarios that ranged from one resembling the average American’s meat diet to a completely meat-free vegan diet.
Perhaps surprisingly, the ovo-lacto and lacto vegetarian diets — which both include dairy products and, in the case of ovo-lacto vegetarians, eggs — showed the potential to feed a larger population than a vegan diet.
The U.S. agricultural system has the capacity to feed a population 1.3 times larger than the current numbers following current consumption patterns, according to the model as determined by USDA food availability data.
By comparison, the ovo-lacto and lacto vegetarian diet scenarios could feed between 2.4 and 2.5 times the size of the current U.S. population using the researchers’ model. A vegan diet could feed a slightly smaller number of people.
This, Peter explained, is because all farmland consists of both cultivated cropland ― where edible products like corn, fruits and vegetables are grown ― and perennial cropland, where plants that are inedible to humans but do not require cultivation, like alfalfa, are grown.
Vegans derive no benefit from the perennial cropland, whereas the ovo-lacto and lacto vegetarians as cows eat the alfalfa and other perennials and then go on to produce the dairy products they eat.
All of this is not to say, Peters added, that going vegan for environmental reasons is a bad step to take. The vegan diet still dramatically out-performed more meat-intensive diets when it came to the number of people it could potentially feed.
“If someone says, ‘I think vegan is the way for me to go,’ one person going vegan does, probably, reduce in a small way the total amount of meat production demands,” Peters told HuffPost. “It’s the behaviors in the whole or the aggregate that matter.”
So why is this important? As Peters noted, the bulk of the food Americans eat comes directly from agricultural production. As the global population increases additional agricultural output is needed, but with expanded farming comes environmental concerns.
Among these are increased greenhouse gas emissions, which are linked to methane production from livestock and improper manure storage on farms. These emissions have already been on the rise in recent years, according to the EPA.
Another issue is nutrient runoff from farms that use excessive fertilizer on their crops. This runoff can cause algal blooms like the “guacamole-thick” ones spotted in Florida recently or those that have grown into a Connecticut-sized dead zone in the Gulf of Mexico.
To address these problems, a delicate balance must be struck between enough, but not too much, farming. And dietary choices should be factored into any consideration of how the U.S. and the world can meet future food needs.
Most importantly, the paper emphasized that there is a big difference between the way that Americans typically eat today and the diet scenarios which showed more efficient use of agricultural land.
Promisingly, though, Americans have been eating less meat over the past decade, reversing a long-standing trend of ever-increasing meat consumption. And new food identities like flexitarian and reducetarian have formed around the idea of eating less meat while not eliminating animal products all together.
Still, though there’s a long way to go toward practicing eating habits that are less resource-dependent, every little bit helps.
“This is a big change for a lot of people,” Peters said. “Is that something that could be achieved within 10 years? Definitely not. It takes a long time for habits to change.”
Joseph Erbentraut covers promising innovations and challenges in the areas of food and water. In addition, Erbentraut explores the evolving ways Americans are identifying and defining themselves. Follow Erbentraut on Twitter at @robojojo. Tips? Email email@example.com.