About a third of the food produced for human consumption is estimated to be lost or wasted globally. But the biggest waste, which is not included in that estimate, may be through dietary choices that result in the squandering of environmental resources. In a study published in the Proceedings of the National Academy of Sciences (PNAS), researchers at the Weizmann Institute of Science and their colleagues have now found a novel way to define and quantify this second type of wastage.
The scientists have called it “opportunity food loss,” a term inspired by the “opportunity cost” concept in economics, which refers to the cost of choosing a particular alternative over better options.
Opportunity food loss stems from using agricultural land to produce animal-based food instead of nutritionally comparable plant-based alternatives. The researchers report that in the United States alone, avoiding opportunity food loss – that is, replacing all animal-based items with edible crops for human consumption – would add enough food to feed 350 million additional people, or more than the total U.S. population, with the same land resources.
“Our analysis has shown that favoring a plant-based diet can potentially yield more food than eliminating all the conventionally defined causes of food loss,” says lead author Dr. Alon Shepon, who works in the lab of Prof. Ron Milo in the Department of Plant and Environmental Sciences. The Weizmann researchers collaborated with Prof. Gidon Eshel of Bard College in New York and Dr. Elad Noor of ETZ Zürich, Switzerland.
The scientists compared the resources needed to produce five major categories of animal-based food – beef, pork, dairy, poultry, and eggs – with the resources required to grow edible crops of similar nutritional value in terms of protein, calories, and micronutrients.
They found that plant-based replacements could produce 2- to 20-fold more protein per acre.
The most dramatic results were obtained for beef. The researchers compared it with a mix of crops – soya, potatoes, cane sugar, peanuts, and garlic – that deliver a similar nutritional profile when taken together in the right proportions.
The land area that could produce 100 grams of protein from these crops would yield only 4 grams of edible protein from beef. In other words, using agricultural land for producing beef instead of replacement crops results in an opportunity food loss of 96 grams – that is, a loss of 96% – per unit of land.
This means that the potential gain from diverting agricultural land from beef to plant-based foods for human consumption would be enormous.