As you scrape food into the trash, do you ever stop to think about all the resources you’re throwing away along with it? The land it was grown on, the water and fertilizer that helped it grow, the energy used to harvest, store and deliver it?
A new study, by researchers from the University of Texas at Austin and Sustainable America, considered these questions by analyzing the resource use associated with our diet, including the portion that gets wasted. Together, these resource and environmental impacts — including energy, land, water and fertilizer use; and greenhouse gas emissions — make up what the authors called a “foodprint.”
The results of the study, which was published in the journal Environmental Research Letters, found that the average adult in the United States in 2010 discarded 35% of available edible food. Embedded in that wasted food is 35% of energy use, 34% of blue water use, 31% of land use, 35% of fertilizer use, and 34% of greenhouse gas emissions that were used to produce that food.
The report focuses only on the food loss and waste that happens at the retail and consumer levels and doesn’t account for losses on the farm and between the primary and retail levels.
Lead author Catherine Birney, of the University of Texas, explains why it’s important to understand how many resources are squandered when food is wasted. “Food waste is unique from other components of foodprint, because there is a significantly higher degree of control by the individual. The changes required to reduce each element are relatively less intrusive on consumer lifestyle.”
In other words, we the people have the power to make a real impact on the environmental burden of food waste. Small behavior changes, like shopping less, serving less, and making the most of what you buy can go a long way toward lowering our foodprint. “While the potential environmental benefits are rather grand, there are also personal financial benefits, through cost savings to be reaped from reducing food waste and overconsumption,” said Birney.
The infographic below details more numbers from the study. It breaks down the average American’s total foodprint per year and the impacts of an adult’s annual amount of wasted food.
As you can see, each adult — through the food they buy but don’t consume — wastes 8 GJ of energy, 451,000 liters of water, 1,051 square meters of land, 17 kilograms of fertilizer and 787 kilograms of CO2E.
Shifting Diets and Habits
The study went on to analyze what the environmental impacts would be if the American diet changed to meet the U.S. Department of Agriculture’s (USDA) nutritional guidelines, and if our consumption habits were to meet the USDA and Environmental Protection Agency’s (EPA) 2030 food waste reduction targets.
The results showed that shifting toward the healthier diet without reducing food waste would result in increases in total food consumption and waste by weight because the healthier diet includes more fruits and vegetable and less calorie-dense animal products. Most of the resource factors studied would increase.
However, if we were to also reach the EPA/USDA goal of a 50% reduction in food waste by 2030, the increased resource use from a healthier diet could be significantly mitigated. Here’s how it would look:
Energy use would increase 12% rather than 34%.
Blue water consumption would go down by 4% instead of increasing by 15%.
Greenhouse gas emissions from food production would go down by 11% rather than up by 7%.
Landfill emissions would decrease by 20% rather than increase by 34%.
Land use would be cut by 32% rather than 19%.
Fertilizer use would increase 12% rather than 34%.
The study points out that moving toward a healthier diet is a worthy goal despite any negative resource impacts. “Instead, the U.S. can focus on an existing goal of reducing food loss and waste to mitigate the consumption of resources related to the U.S. food system,” said Dr. Michael E. Webber, senior author of the study and author of Thirst for Power: Energy, Water and Human Survival.
Webber said this is not the first study to look at the link between the USDA dietary guidelines and environmental impacts, but it is the first to incorporate the role of food waste and loss. “By understanding the scale of resource impacts of food we can start to identify solutions,” said Webber. “Reducing food waste seems like an obvious place to start.”
Webber also offers a few solutions. “At the individual level we should serve ourselves smaller portions and eat all that we serve,” he said. “At the supply-chain level we need tighter control on temperatures and conditions to avoid spoilage.”
Much more can be done to reduce food waste, and there are many ways Americans can contribute. To start, share our infographic, then check out ivaluefood.com where you’ll find helpful resources and take a challenge to find out what’s going to waste in your own home.