Interview Summary

Norbert: Kathryn, let’s begin with the big-picture question. Why should we care what people do with their food once they have purchased it?

Kathryn: Great question. So we know that food waste has huge environmental and economic impacts. Thirty percent of food that’s produced for human consumption ends up going uneaten. When that food is wasted, we know that all the resources associated with producing it, such as land and water, are also wasted. And those resources themselves have their own cost. Decomposing food emits methane, which is a greenhouse gas that is 25 times more potent than carbon dioxide. There’s also emissions from the transportation and distribution of that food from farmer to consumer. I don’t think that most people set out to waste food, nor do they feel really good about doing it. In addition, households fall at the end of the supply chain, so consequences from upstream decisions made by manufacturers and distributors, may fall on the households themselves. For example, if there’s milk that has not been kept cold along the supply chain, the consumer may end up throwing it away because it starts smelling or tasting off sooner than it really should. Another example is dates placed on food packages. Producers have more information about the quality and the safety of their product than consumers do. Many individuals use those dates on the package to determine when they should throw something away. If producers are conservative in this labeling, or if that language is unclear, consumers may the discard perfectly good food based on the date alone. If we can identify policies aimed at producers to effectively communicate information about the product to the consumer, as well as methods such as strict adherence to cold chain processes, we could help reduce food waste at the household level. I think, overall, we want to develop the tools necessary to set consumers up for success in minimizing their food waste.

Brenna: Kathryn, thanks so much, for laying out all the reasons why we should care about this topic. We so appreciate the work you and Brian are doing to help us better understand it. So with that, Brian, can I turn to you? Would you mind telling our listeners about the national tracking survey, what you all are hoping to learn, and some of the findings you have so far?

Brian: Sure. The United States set a national food waste reduction goal back in 2015. Three different administrations from vastly different political viewpoints have all kind of gotten behind that, and really want to see that goal met. And yet, we don’t have great data to track how our food waste habits are changing over time. Particularly for consumers. Some other sources of data suggest consumers are the source for 40% to 50% of wasted food that we see. We really wanted to try to start to develop some data in this area. Hence, we set up a national tracking survey. We used an online survey approach, which has some known issues with it. It tends to under report the absolute level. But we’re asking the same questions over and over again – we now have seven waves of data collection between 2021 and 2023. We have a consistently asked set of questions that we can use to understand patterns and trends that might be emerging across the country among consumers as they’re wasting food in their households, and this helps us get perhaps a bit more level with the United Kingdom. They have got this great survey data series that they use with consumers to track food waste going back to, I believe it’s the early 2000 and teens. We really hope to learn some things from our findings, and we are seeing some interesting patterns emerge.

Brenna: It’s great that you are starting a tracking survey. Most of us on the podcast work on food waste, and we know that it can get literally very messy trying to measure it in other ways. There are limitations in all the ways measuring. I appreciate the work that you all are doing. So Brian, you started collecting data as Covid restrictions were lifting. Why did you choose this time to start the tracking survey?

Brian: That’s just kind of when we got organized. My early research portfolio was very focused on going into homes with apps and things like that to get a very granular view of food waste. But then, it kind of really struck me that we need to have data on consumers, even if it’s not perfect. We need to ask those questions consistently. That’s when we were able to muster our resources and begin to collect the tracking data. With the help of the National Science Foundation, we’ve been able to solidify that tracking approach and now we have a funding stream that will allow us to continue this for at least five years. That’s very helpful.

Brenna: Perfect, thanks for clarifying that. Kathryn, if we can come back to you. According to the Bureau of Labor Statistics, food-at-home prices rose 8.6% over the period of your study. I’m curious why consumers were actually wasting more food as food prices are going up.

Kathryn: I think it really comes down to how consumers are managing their food stock at home. Two things that we noted from this study was that over that year we analyzed, food that was bought in bulk and was subsequently thrown away doubled. So increased food prices may have prompted households to purchase more food in bulk. We also found in a previous study that households really increased their cold storage capacity by buying refrigerators and freezers during lockdown. I think that the increase in cold storage capacity and purchasing more bulk food adds kind of this new dimension to food stock management that households may not have adjusted to yet. We also saw that food waste attributed to unplanned dining out events increased. This makes sense as we were able to go out more. Restaurants weren’t closed down, and didn’t have as many restrictions. We were able to go out more, and we had more food that was wasted because we planned on eating at home. But we took advantage of an opportunity instead to go out with friends or something like that. So as people go back to their more hectic lifestyles, I think that just food management becomes a little bit more difficult. We need to make sure that we provide support and educational campaigns to help households manage their food at home. With higher prices being at the forefront of a lot of people’s minds right now, I think that highlighting food waste reduction is a great method to save money.

Norbert: Kathryn, that’s really interesting, and it makes me think of a couple of studies that I’ve done with Brenna and our colleague Linlin, and some other work that I’ve done, where we did see a relationship between the price of food and the predicted waste. What we saw was that there was a negative relationship. So it’s interesting to hear this example of increases in the price leading to or at least associated with this increase in food waste. But, I think what’s really fascinating is it may be a reduction in the per-unit cost because people were buying in larger quantities. That’s a really fascinating thing. One of the things that we were looking at right when Covid started, people were reducing their food away from home significantly as we weren’t allowed to go out and we weren’t ordering out. So, it’s interesting to see this kind of change. I look forward to seeing what subsequent rounds of the survey will show about what happens with food waste and hopefully as price inflation goes down. Brian, I want to turn back to you and ask: a 280% year over year increase in food waste is really high. Do you expect that food waste will continue to increase at this rate?

Brian: Yeah, we’ve actually got some data in on that now. So the published data shows that 280% increase between the beginning of 2021 and the beginning of 2022. That was right after the Omicron Christmas, if we remember that, and vaccines were coming on board. What we’ve shown now is that behavior has retracted a bit. We’re down to now merely a 200% increase from that February ’21 wave to the February ’23 wave two years later. So it came down from that 280% peak to a doubling of food waste between early Covid days to back-to-reality-here for many people in February 2023. I think part of that is what Kathryn talked about before. That we had probably a big purge, I would guess that spring cleaning after Omicron, right? People probably were sitting on a fair amount of money in terms of finances. Restaurants were really fully reopening. They went out unexpectedly, spur of the moment, ate out during their reporting week and that caused them to report more waste. They probably looked through their cupboards and saw all this bulk stuff they might have bought during Covid and said spring cleaning time. Maybe we need to get rid of some of that stuff as the date labels grew longer and longer in the past. Once they got that out of their system, and this is the thing, we don’t know what pre-Covid was, but maybe this is kind of a return to pre-Covid level. We’ll never know that because we can’t reproduce data that we don’t have to pre-Covid days, but perhaps that February 2021 was kind of that peak studying our fridge over and over again trying to find every last leftover and shows a very low level. The data that we’re getting here in February of 2023 is kind of a return to normal. That’s what’s happened in the United Kingdom as well, where they do have a longer tracking survey. They found right after the onset of Covid, a pretty big drop in reported food waste; about by half in terms of their metric. And then, a kind of a slow but steady march back towards pre-Covid numbers is what they found right about the end of 2022. So a little bit different in the pattern, but not dissimilar in terms of overall trends.

Norbert: Your explanation makes really good sense, and so thanks for explaining that. I’m hopeful that this is going back to a lower rate of waste. It will be important to see how subsequent surveys tell us what happens with food waste as we move forward, and hopefully without a pandemic in between.

Brian: And perhaps new approaches to finding other sources of data so that can maybe validate our hypotheses here about what’s going on with these trends, would also be very important. It’s nice to have tracking survey data, but it’s correlative, right? We’re not doing any randomized experiments here to be able to understand the true links and causality. So as always, we need more research to validate this to help us understand how we can jump in, intervene and help the US meet its long-term food waste reduction goals.