Last fall, teams of students working for Portland State University's Community Environmental Services unit fanned out across five Oregon Communities (Portland, Gresham, Salem, Woodburn, and Redmond) in search of volunteers to participate in a study of residential household wasted food. Nearly 300 households signed up, agreeing to complete surveys, keep diaries tracking food they got rid of, and their reasons for tossing it and participate in a wasted food audit. The study aimed to gather data to establish baseline metrics for quantities and types of edible food thrown out in Oregon homes and shed light on why people waste food. The Oregon Department of Environmental Quality (DEQ) sponsored the project, which is part of the state's long-term plans to produce and use materials responsibly while conserving resources, protecting the environment, and improving quality of life for all Oregonians.
Research from the Natural Resource Defense Council suggests that up to 40 percent of food grown, produced, or imported for consumption in the US goes to waste. Whether it's left in the field, going in the trash, compost bin, or down the drain, wasted food squanders resources. According to ReFED, a nonprofit organization that works to reduce wasted food each year, the food we don't eat costs consumers, businesses, and farms in the US $218 billion. The production and distribution of that food require enormous energy, water, land, and other resources. When left in the field or shipped to a landfill or composting facility, food becomes a methane source, a potent greenhouse gas. The economic and environmental impacts of this waste are compounded by the problem of food insecurity, particularly in states like Oregon, where hundreds of thousands of residents do not have access to sufficient supplies of nutritious food.
In early 2017, DEQ created a strategic plan outlining the steps the state would take over five years to reduce food waste from upstream production, through consumer use, to end-of-product-lifecycle management. In that plan, the department set goals for preventing food waste that included filling knowledge gaps, increasing consumer and business actions that prevent waste, reducing greenhouse gas emissions, and conserving resources. The department also laid out nine activities it would undertake in support of these goals. The first project on the department's list was a study examining wasted food in residential, industrial, commercial, and institutional settings. The study would help the state better understand how much food goes to waste in Oregon and its reasons. To conduct the five-part study, the department turned to Christa McDermott, director of PSU's Community Environmental Services unit. McDermott and graduate research assistant Chris de Vencia recently reported findings from the portion of the study that looked at wasted food at the household level.
"There's been a growing recognition that wasted food is a serious problem," McDermott said. "What we found when we analyzed the data we collected in five Oregon communities is similar to what other studies have shown: that almost 40 percent of what's going into the trash, compost bin, or down the drain is food and nearly three-quarters of that is edible. It's a huge waste of resources."
To establish a baseline of wasted food from residential sources, student workers in the Community Environmental Services unit recruited 299 households from rural and urban communities, representing a wide range of demographic characteristics, to participate in the study. Some received curbside composting services. Some did not. Participants provided qualitative and quantitative information through surveys designed by PSU's Survey Research Lab and in kitchen diaries where they recorded what they disposed of and why. The students also donned gloves, goggles, coveralls, and respirators to comb through trash and compost bins, weighing wasted food and sorting it by categories including inedible (e.g., eggshells, coffee grounds, and banana peels), meat and fish, dairy, eggs, fruits and vegetables, baked goods, dry foods, etc.
The research team found that, over seven days, the average weight of food urban and rural households sent to composting facilities and landfills was 7.1 lbs., 4.9 lbs. of which was edible. The analysis showed no statistically significant difference in the amount of wasted food generated by urban and rural households. Per capita, participants sent an average of 2.9 lbs. of food to landfills and composting facilities, with 65 percent, or 1.9 lbs., is edible.
At an average of 2.3 lbs., inedible food was the largest category of waste urban and rural households sent to landfills and composting facilities. Vegetables and fruits, prepared foods, baked goods, meats and fish, and snacks/condiments were the top five groups of edible wasted food disposed of by the study's participants, accounting for an average of 2.4 lbs. of all wasted food. The research team also found that over 40 percent of food participants reported disposing of was not part of a meal (breakfast, lunch, or dinner).
Participants noted reasons for throwing out food in diaries. Topping the list of reasons by a margin of two-to-one was items having gone bad. At just over 16 percent, the second reason people gave for disposing of food was that they didn't care for or were tired of eating it. The third reason folks gave was that particular items were not as good as leftovers.
The study also asked participants about their reasons for wasting food. Nearly 50 percent reported throwing away food either because they made too much or lost track of what they had in the refrigerator. Other reasons for wasting food included: they bought too much, didn't know how to use, had storage issues, and scheduling problems.
In addition to asking participants the type and quantity of foods they threw out and their reasons for doing so, the study solicited information about where and how frequently people went grocery shopping, how much money they spent on food items, their attitudes about food and wasting food, and their meal planning and shopping behaviors.
"In a perfect world, there would be no wasted food at all," said Ashley Zanolli, Senior Policy and Program Advisor for DEQ's Materials Management Program. "But as it turns out, a lot of what ends up in the trash is edible food. At the DEQ, we're engaging in reducing the number of materials consumed in Oregon by 40 percent by 2050. Reducing the wasting of food is one of the best ways we have to achieve that goal. PSU's wasted food measurement study is a key component of that plan. It's foundational research that helps us understand behaviors, develop interventions, and track progress as we try to reduce food waste in the state."
According to Metro, residents, and businesses in the Portland area alone waste enough food to fill 5,000 semi-trucks every year, a governing agency for the Portland metropolitan region. While it's likely that some of that food may have been diverted from landfills, ending up at composting facilities or converted into energy or fertilizers, commercial and residential curbside composting services are by no means ubiquitous throughout the region or state, meaning much of the food we waste ends up in landfills. And when we toss out food fit for consumption, regardless of whether it ends up in a composting facility, landfill, or down the drain, we're also wasting the resources that went into its production and distribution.
"Whether it's food getting lost in the fridge, buying or making too much, or people being too busy to make or eat food at home, we're very much aware that consumer behavior plays a big role in the wasting of food," McDermott said. "But consumer behavior is embedded in larger structures that we often have very little control over. There's certainly a lot we can do to reduce food waste on an individual level, but there's so much more to do on a collective level. We hope this study will bring greater awareness and fresh ideas to approaches that could result in the kinds of individual and systemic changes needed to reduce the wasting of food in Oregon."
If there exists a single path to reducing food insecurity, conserving natural resources, combating climate change, and reducing the costs associated with producing food, it's through reducing waste. And if we want to follow that path, it will require the concerted efforts of individuals, families, businesses, institutions, industry, and agriculture alike. With an idea of how much food goes to waste in Oregon and the reasons why it's thrown out, the DEQ can begin the process of developing interventions that target the wasting of food and precious resources across the board throughout the state.