by Stuti Mankodi

What is the first image that comes to mind when you think about food waste? Is it the unfinished bits on your plate after a meal? The old lettuce and cheese you toss when you clean out your refrigerator? Or perhaps the leftover meals a restaurant made that went uneaten. In reality, the problem of food waste is much larger: it’s a global crisis with environmental, economic, and ethical implications. According to the United Nations, about one-third of all food produced for human consumption is wasted every year. Food loss and waste occurs at every stage of food production — from farms to kitchens to consumers — and contributes significantly to greenhouse gas emissions. 

At Penn, researchers and practitioners come at the food waste problem from many directions. There are faculty such as Zhengxia Dou, a professor of agricultural systems, whose research at the School of Veterinary Medicine’s New Bolton Center addresses agricultural nutrients and sustainable food security issues. In campus dining, we have professionals in food sourcing and preparation like Chef Shazad Khan and Director of Operations Steven Green from Penn Dining. To understand efforts to reduce food waste at different points in the system, the Environmental Innovations Initiative spoke with all three of these experts. They shared insights into both upstream agricultural innovations and downstream dining practices on campus.

Q. How do you define the food waste problem?

Zhengxia Dou: Food loss and waste occur throughout the supply chain — production in the agriculture fields, post-harvest handling, processing, distribution, marketplace, and consumption. Fruits and vegetables, which are nutritious but perishable, have the highest loss and waste rates — about half of the total. Some losses result from human ignorance, poor management, or consumer pickiness. Even slightly blemished produce retains nutritional value, but consumers often reject it, leading to unnecessary waste.

Steven Green: We define food waste as anything that was purchased and prepared to be served but does not get served. Our hierarchy for handling food waste prioritizes repurposing it, sending it to biofuel or animal feed, composting, and only as a last resort, landfilling. 

Shazad Khan: From a culinary side, food waste includes everything from production scraps, such as pineapple skins, to leftovers from catered events. We track food waste closely and make operational decisions based on it. Food waste management is treated with the same level of importance as safety and sanitation in our meetings.

Q. How do you approach food waste in your work?

Dou: We partnered with a local fruit processing center to collect discarded citrus waste and incorporated it into cows’ diets at our research dairy farm at New Bolton Center. This practice reduced landfill emissions, displaced standard feed ingredients like corn and hay, and still maintained milk yield and quality. Later, we experimented with preserving fresh fruit waste through fermentation to extend its usability. We have also tested vegetable and fruit mixtures in laboratory studies.

Green: We focus on repurposing food through donations, using surplus food for animal feed, creating biofuel, or composting, always aiming to keep waste out of landfills. We collaborate closely with partners like Bennet Compost to manage our waste responsibly. 

Shazad: Whenever we have surplus due to event overestimates or closures, we engage in food recovery programs, donating food in prime condition to local organizations. Planning menus carefully, training chefs, and continuously reviewing waste data help us cut down unnecessary waste. Every week we meet to discuss waste management, in addition to finances and safety.

Q. What challenges make food waste hard to eliminate?

Dou: Consumer behavior is a major challenge. In developed countries, food is cheap and abundant, so people often don't appreciate the resources used to produce it. There's also a lack of connection between consumers and the food production process. Raising awareness is essential to change behavior.

Green: Mindfulness around portion control is key. While Penn Dining works hard to reduce waste behind the scenes, it's equally important for students and other diners to be mindful about how much they take. Choosing reasonable portions helps prevent waste at the consumer end.

Khan: The all-you-can-eat style in dining halls can sometimes encourage students to take more food than they need. We try to address this by educating students through waste awareness events, where they can see firsthand how much food waste accumulates from a dining hall in a single day. 

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Q. What innovations or future solutions are exciting?

Dou: Zero landfill food waste policies are crucial. We need a combination of composting, anaerobic digestion, and animal feed solutions. I'm excited about emerging work using insects like black soldier flies to turn food waste into protein sources for animal feed, or even ingredients for potential human uses.

Green: Compostable materials are improving. More compostable napkins, plates, and containers are becoming available, and industry partners are prioritizing sustainable packaging. Our focus now includes working with vendors who provide compostable, recyclable materials, especially for takeout containers after the rise in to-go dining during COVID.

Khan: Technology is evolving rapidly. We are beginning to see robotic cooking systems and AI-supported kitchen operations, which could help optimize portion sizes and further reduce waste. Programs like Waste Not already allow us to track daily waste levels. We also recently introduced the Reuzzi app, which helps students manage reusable to-go containers, encouraging sustainable habits through simple mobile tracking.

Q. How important is consumer awareness and behavior change?

Dou: Awareness is powerful. Once consumers realize the fertilizers, fuel, land, and labor embedded in every apple or pepper, they begin to respect food more and waste less.

Green: Mindfulness and consciousness at both the front end — choosing portions carefully — and the back end — separating waste properly — are critical. No waste program can succeed without the active participation of consumers.

Khan: Students at Penn are generally informed and motivated to help, and we believe there's always room to grow. Showing students tangible data about waste volumes or having them see where their compost goes makes a lasting impact. Seeing the full cycle — from food production to waste recovery — builds a stronger sustainability mindset.