FACULTY Q&A

Shelie Miller

As the coronavirus continues to spread around the world, University of Michigan sustainability expert Shelie Miller discusses grocery shopping behavior, panic buying, the supply chain and food waste.

Miller is an associate professor at the U-M School for Environment and Sustainability and director of the U-M Program in the Environment. She is an environmental engineer who studies food supply chains, food waste and the environmental impact of food.

What effect is panic buying in grocery stores likely to have on the amount of food waste generated in the United States?

Under normal circumstances, Americans waste an incredible amount of food, with 30 to 40% of produced food ending up as waste. Panic shopping increases the potential for household food waste, since large quantities of perishable items are likely to spoil before they can be used. Wasting food wastes money, so planning ahead and being thoughtful about what you buy saves money and also reduces stress on the food system.

Is there a legitimate threat to the U.S. food supply from this pandemic? What practices would you recommend for grocery shoppers?

There is no expectation that stores will run out of food or that grocery stores will close. Therefore, it is important to only buy what you think your household will consume before it goes bad.

The best behaviors you can follow are:

• Create a meal plan and shopping list, being sure to plan for snacks and treats.
• Stick to your shopping list.
• Only buy food that you actually expect to eat.
• Remember that the shelf life of fresh fruits and vegetables can vary from a few days to several weeks.
• Plan to eat, prepare and/or freeze perishable items before they spoil.
• Be mindful of how much storage you have. If you plan to freeze ingredients or make meals ahead to freeze, make sure you have enough space in your freezer.
• Be creative with pantry items and other foods you have on hand to reduce the number of overall grocery trips you need to make.

As long as everyone only purchases what they can reasonably expect to eat, there will be less stress on grocery stores to meet demand. Grocery stores will have the opportunity to catch up and restock shelves.

What are some of the current stresses on the food supply chain?

Stores are running temporarily low on some items because they are not equipped to keep up with the current level of demand. Grocery stores are designed for the normal pattern of consumer food shopping behavior, optimizing shelf space, labor to restock shelves, backroom storage capacity, and loading/shipping docks that accommodate typical consumer flows.

Regional distribution centers are similarly designed and optimized. We are seeing a disruption in how people are shopping as a result of the coronavirus, which is causing bottlenecks in the existing system. As one example, a grocery store can only unload a given number of trucks in a single day. An empty shelf does not indicate that there is a shortage of that item. Instead, it is much more likely that the current system of distribution has been unable to adjust to the major changes in consumer shopping behavior.

Bottlenecks in distribution and stocking may continue if consumers continue to purchase and stockpile major quantities of food. But after the initial rounds of panic shopping, I expect that the food system will be able to catch up.

Is online shopping for delivery a better option than going to the grocery store?

Online grocery shopping is available in many areas, either for grocery delivery or curbside pickup. Placing an order online reduces the amount of interpersonal contact, and consumers should take advantage of that option if they can.

Unfortunately, most online systems are not currently designed for the demand volumes that are being experienced and may be unable to keep up in the short term. Consumers wishing to take advantage of online grocery delivery and pickup systems may not be able to do so until there is improved capacity to meet the high demand. As the current stress on the food system decreases, I would expect online grocery options to become easier to schedule.

What is the connection between social distancing and protection of the food supply chain during a pandemic?

The reliability of the food system depends on the health and safety of its workers. People are involved in every aspect of the food system, from farming, processing, shipping, stocking and preparing food. In order to keep these essential personnel healthy and at work, it is important to reduce the spread of the virus and follow all guidance from health officials.