UIUC research shows smaller plates reduce food waste in dining halls

UI dining hall

Research conducted by University of Illinois at Urbana-Champaign scientists from two departments within the College of Agricultural, Consumer, and Environmental Sciences (ACES) demonstrates that the simple act of changing plate size and shape can have a significant impact on food waste in university dining halls.

In an article published in May 2021 in the journal Resources, Conservation & Recycling, authors Rachel Richardson [former graduate student in the Department of Agricultural and Consumer Economics (ACE)], Melissa Pflugh Prescott (assistant professor in the Department of Food Science and Human Nutrition), and Brenna Ellison (associate professor in the associate professor in ACE) describe data collected at two dining halls on the Illinois campus in the Fall of 2018. The researchers and dining hall staff monitored and limited the dishware available for patron use.  The only intervention in this study was a change in plate size and shape. Traditionally, the university dining facilities used round plates (9″x9”). In this study, the round plates were replaced with oval platters (9.75″x7.75″), decreasing the plate’s surface area by 6.76%. Both the round and oval plates were tested at each dining hall, and the menu offered was the same for both plate types.

After diners selected their food, but before they sat down at a table, researchers approached them and asked permission to take a picture of their plates and to weigh the plate of food. Participation was incentivized with an entry in a later drawing for a $50 Amazon gift card. Participating diners additionally filled out a survey, and when their plates were brought to the dish return, the researchers took a post-consumption picture and weight measurement. The survey included a question about whether diners went back for seconds; in that circumstance, a post-consumption weight was not recorded.

A total of 1825 observations were collected with 1285 observations retained for analysis. Observations were excluded if the participant: only selected food using non-standard dishware (e.g., only eating a bowl of soup); submitted an incomplete survey; was missing a pre- or post-consumption photo; did not return their plate; or returned plates with different food on them than selected.

Overall, food waste went down from 15.8% of food selected for round plates to 11.8% for oval plates. This amounts to nearly 20 grams (0.7 oz) less food waste per plate. In a setting where thousands of meals are served, this seemingly small reduction could quickly add up. The researchers concluded that changing plate type is a viable strategy to reduce food waste, though dining hall managers need to weigh the cost of purchasing new plates against the potential savings. They speculate that combining the direct-nudge approach of smaller plates with an education campaign could be even more effective.

Read the full article at https://doi.org/10.1016/j.resconrec.2020.105293.

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Note: This post was originally published on the ISTC Green Lunchroom Challenge blog, which is maintained by Technical Assistance Program staff. Check out that blog for more news, resources, and tips on preventing food waste and diverting food from landfills via rescue, repurposing, composting, and other strategies.

Green Lunchroom Challenge to Assist IL Schools with Food Waste Prevention, Reduction

According to the Natural Resources Defense Council, food production represents 10 percent of the total US energy budget, uses 50 percent of US land, and accounts for 80 percent of the freshwater we consume–yet, 40 percent of food in the US goes uneaten. And in 2013, 49.1 million Americans lived in food insecure households, including 33.3 million adults and 15.8 million children. Food waste is clearly both a tremendous problem and opportunity for improving the sustainability of our society. Reducing food waste in schools not only helps to ensure those precious expended resources are providing nutrition as intended, but also provides the opportunity to set important examples of conservation and systems thinking among our impressionable youth, which will hopefully stay with them as they become our next generation of leaders.

 

The Illinois Sustainable Technology Center (ISTC) is therefore pleased to announce an exciting new project that addresses this important societal and environmental challenge. In order to identify sources of food waste in K-12 schools and facilitate its prevention and reduction, ISTC, in collaboration with the Illinois State Board of Education (ISBE), UI Extension, and Beyond Green Partners, Inc., is launching the Green Lunchroom Challenge this fall. Funded by US EPA Region 5, the program is open for participation from K-12 schools throughout the state. Marketing of the program will however, be targeted toward underserved regions of southern Illinois, including Pulaski, Alexander, Marion, White, and Fayette counties. According to data from the ISBE, over 70 percent of K-12 students in those counties are eligible for assistance through the National School Lunch Program. By preventing and reducing food waste in these areas particularly, and throughout the state, it is hoped the Challenge will not only achieve environmental benefits, but also stretch federal and state assistance and resources through increased efficiency.

 

school kids in cafeteria
Photo: USDA Blog

 

Similar to the successful Illinois Green Office Challenge, the Green Lunchroom Challenge is a voluntary, “friendly competition,” in which participating schools will choose among a variety of suggested activities to improve the sustainability of their food service. These activities will range in complexity and commitment to allow participants to best suit their situation, budget, and available community resources. Examples might include, but not be limited to, composting of food scraps, use of creative entree names and careful relative placement of food choices to reduce waste of fruit and vegetables, donation of unused food to local food banks or shelters, etc. In addition to operationally related activities, schools may also choose to integrate food waste prevention and reduction into curricula, helping students learn about food security and hunger, composting, the circular economy, and stewardship. Resources and guidance will be available on the project web site and from ISTC technical assistance staff for each recommended activity, and participants will earn points for every activity they complete. Relative progress will be displayed on an online leaderboard. On Earth Day 2016, the participating public K-12 school with the most points will be declared the winner for the year and will receive public recognition and a prize (to be determined) to foster continuous improvement.

 

A kickoff workshop will be held in September 2015 (date and location to be announced) to introduce the Challenge; identify (in part through feedback from school and district representatives in attendance) key sources of food waste in schools, as well as barriers to its prevention; to raise awareness among potential participants of existing relevant toolkits and programs; and to provide comprehensive training on analysis and modification of menus, food procurement and inventory, lunchroom procedures, etc. Note that a school does not need to participate in the workshop to participate in the Challenge, and schools may register throughout the Challenge period (Sept. 1, 2015- April 1, 2016). While the competition is only open to K-12 schools in Illinois, ISTC hopes that other states and organizations beyond schools will be able to use resources developed for the Challenge to guide food waste reduction and prevention in their operations and regions.

 

Interested parties may contact Joy Scrogum with questions or to request addition to the mailing list for more information on the workshop and activities as it becomes available. The project web site will be available soon, and potential participants will be able to sign up to receive further information there as well. (The URL for the program web site will be posted in the comments of this post as soon as it is live.)

 

cafeteria tray
Photo by Tim Lauer, principal of Meriwether Lewis Elementary School in Portland, Oregon