Episode 6: Food waste: Why does it matter and what can we do?

Why do we waste so much food, and what does it mean for both the environment and our diets?

In this episode, hosts Adam Fogarasi and Gretchen Repasky explore food waste as a major, yet often overlooked, sustainability challenge. Drawing on research from consumer behavior and food systems, the episode highlights how a significant share of global food production is never consumed, resulting in a substantial loss of resources including water, land and energy.

The conversation examines where food waste occurs across the supply chain and shows how patterns differ between contexts. While losses often occur earlier in the system in lower-income settings, a large share of food waste in high-income countries takes place in households, driven by everyday behaviors such as over-purchasing, poor planning and confusion around date labels.

Featuring Professor Jessica Aschemann-Witzel, Aarhus University, the episode also highlights how both the type and amount of food wasted matter. Plant-based foods are often wasted in larger quantities, while animal-based products tend to carry a higher environmental impact per unit.

At its core, the episode shows that reducing food waste is one of the most effective ways to lower the environmental footprint of our diets. Rather than requiring major changes, it emphasises small, practical actions that can be integrated into everyday life and contribute to more sustainable eating patterns over time.

Episode info

Guests

Jessica Aschemann-Witzel, Centre Director of MAPP, Professor at Department of Management, Aarhus University

Hosts
Adam Fogarasi, PhD student, University of Copenhagen
Gretchen Repasky, Center Scientific Manager, Center for Protein Design, University of Copenhagen

Publisher
Danish Diabetes and Endocrine Academy

Audio engineering
Periscope

Producer
Adam Fogarasi
Gretchen Repasky

Transcript

SPEAKER_01 0:02

Welcome back to Healthy People Healthy Planets. This show where we explore how and what we eat shapes both our health and our planet. I'm Adam.

SPEAKER_02 0:11

And I'm Gretchen. Together, we're gonna guide you through what science says about how our food choices shape the world around us.

SPEAKER_01 0:22

Today's topic is something we rarely think about when talking about diets. But it's one of the biggest hidden drivers of environmental change. And Gretchen, you know what that is? Food waste.

SPEAKER_02 0:36

Wow. Globally, around one-third of all the food produced never gets eaten. One third. Imagine filling three grocery bags and then throwing one straight away into the bin before you even unpack it.

SPEAKER_01 0:55

And it's not only about the food itself, it's about wasted resources, the water used to grow the crops, the land, the energy, the labor.

SPEAKER_02 1:06

So today we're asking, why do we waste so much food? Where does it happen? And most importantly, what can we do about it?

SPEAKER_01 1:23

Food waste is estimated at 25 to 30 percent of all global production. That's nearly one in three food items produced that never make it into someone's stomach. And the impact is huge. Greenhouse gases, wasted food, rottening in landfills, releases methane, water, about a quarter of all agricultural water is lost because of wasted food. Land, millions of hectares are used to grow crops that never got eaten.

SPEAKER_02 1:57

That's staggering. If food waste were a country, it would be one of the biggest emitters of greenhouse gases. Let's learn a little bit more from an expert.

SPEAKER_00 2:25

Mostly about topics like health and sustainability. And I'm working at the MAP Center where I'm a professor and center director, and that is at Aarhus University. A lot of people know that a third of the food in the world that is produced is wasted or lost. Lost is when it's lost in the supply chain, and wasted is when it's actually already a food and is wasted. So that means, of course, there is a lot of resources that are lost that are embedded in these products. So the more something already has been transported or processed, the more resources have been spent on the transport, on the processing, and the more is embedded that is lost when you don't eat the food. So in that sense, wasting a steak has a bigger impact is sort of worse than wasting a few potatoes, because there's a much more resources embedded that have been used. And of course, there's also some more resources that are spent when you waste something, because the disposal stage can also emit further resources. So that is the reason why it's a big topic, because um wasting resources is not good if we want to actually reduce our use of resources. If we think about early in the supply chain, of course, fruit and vegetables is more likely lost early in the supply chain. Um generally, different food categories, then the question is also is it about the amount? If you look at the rate, um you have a different result compared to if you look at what is the environmental impact. Um so, for example, wasting a bit of meat can it could have a really high embedded CO2, but it's it's quantity-wise or or rate-wise, it's it's not that much. So if you look at the rate of food waste, it's often fruit and vegetable and bread that has is highest. So these are the typical categories wasted most. And actually also differs a bit between countries, what is wasted more or less. And I think most people, if you think about when you're in the restaurant, you cannot eat up your plate. Um most people also, because of cultural reasons, start eating up the meat first and then waste some of the potatoes especially, or maybe some of the fruit and vegetable, or the vegetable mostly. So I mean we also do that in a way, in a way it nicely fits together.

SPEAKER_02 4:48

So, Adam, I learned that food waste isn't only about wasted food itself, but also about all the resources behind it, like water, land, energy, and transport.

SPEAKER_01 5:03

And to really understand food waste, we need to look at how different parts of the food system fit together.

SPEAKER_02 5:14

Food waste happens all along the supply chain. At farms, crops can be left unharvested if they don't meet standards. During storage and transport, food can spoil. Retailers actually throw out products that reach their best before date.

SPEAKER_01 5:32

But you know what, Gretchen? The biggest share actually happens in our homes. More than half of all food waste in many countries comes from household leftovers, spoiled food in the fridge, or confusion over date labels.

SPEAKER_02 5:46

To help us understand where food waste actually happens, we asked Jessica to explain how it differs across food systems and even across countries.

SPEAKER_00 5:58

The studies show that the richer the country, the more food waste is in households. And the poorer the country, the more food waste or food loss is in the earlier supply chain. Because if you have a really good infrastructure, then you don't lose that much already on the field or in the transport. And in poor countries, a lot is lost during transport. It's often also warm countries. So a pineapple that is standing in a traffic jam on a really badly um produced street is of course lost more easily. It doesn't happen that much in the developed countries. But there because we are affluent and we are rich, the cost of food doesn't um play that much of a role for us. We maybe only spend 10% of our income on food, and that's why the majority of food waste in um developed countries happens in the household, and the majority of food loss happen in poorer countries happens in the earlier part of the supply chain.

SPEAKER_01 6:56

So where food waste happens depends a lot on the context, actually.

SPEAKER_02 7:01

In wealthy countries, most food waste happens in households.

SPEAKER_01 7:05

While in low-income settings, more food is lost earlier in the supply chain.

SPEAKER_02 7:10

So, how does food waste link to sustainable diets? Coming up next, we'll explore that connection.

SPEAKER_01 7:23

When we talk about sustainable diets, we often focus on eating more plants. But here is a big twist. Most food waste comes from plant foods like fruits, vegetables, and bread.

SPEAKER_02 7:37

That doesn't mean we should avoid them, right? It means instead that we need to value them more. And while they're less resource-intensive than some animal-based products, the sheer volume wasted makes their impact significant.

SPEAKER_01 7:54

Animal-based foods are wasted less often, but each portion wasted has a very high footprint. So reducing waste across the board is essential.

SPEAKER_02 8:07

Adam, let's find out how food waste fits into the bigger sustainability picture.

SPEAKER_01 8:14

And whether some foods affect that more than others.

SPEAKER_00 8:18

In marketing and work with marketing, we work a lot with different segmentation studies. And I've been looking at a lot of segmentation studies. And when it comes to food, there's something that comes again and again, especially when you look into the health and sustainability topic. And that is that people who are interested in health, they're also often overlapping with people with being a person who's interested in sustainability. So there's a strong correlation between health and sustainability. There's also typically sort of a difference between there's some consumers who are very much into being green and healthy, and others who are the opposite. And though that is a bit boring, but it's kind of following stereotypes, there is a difference between age and gender, especially in age, that often a lot of studies, when it looks into health and sustainability, younger, more educated city females are more into that subject than older, less educated males. So if you do studies where you segment into different types of consumer profiles, you typically find some group of young males who are not really into food and they're not really interested in it, don't care about anything when it comes to which food they eat, and then younger females who are really into it. So there's a it's it's kind of seems very stereotypical, but it's actually also what we find in the data. That doesn't mean that people are not different. There's a lot of very engaged vegan males, but but and there's also older males who are maybe very much into health and sustainability. But if one really looks at the averages, there is a lot of stereotypes that seem to also be based on the facts. When it comes to sustainability, there's also a lot of people maybe on the rural landscape in the rural areas who have a lower impact, but they're actually not that much into sustainability. But they are maybe sort of using less resources because um they have a more traditional lifestyle, in that sense, traditional that they're actually not using that many. So they're more kind of um using less resources, um, using up what they have, um so being more frugal in a way. That maybe doesn't hold for for health topics, but for sustainability topics, there's also kind of a more rural frugal group that has a lower impact in terms of sustainability.

SPEAKER_02 10:43

So to recap, now I see that different foods do indeed have different effects when it comes to food waste and sustainability. Some foods are wasted in larger amounts, while others may be wasted less or less often, but those could still carry a higher environmental cost per item. So both the type of food and the amount of food wasted matter. So, Adam, why do we waste so much?

SPEAKER_01 11:18

Well, I think it's often not intentional. You know, habits, cultural, and the practical barriers all play a role.

SPEAKER_02 11:28

Yeah, but I bet we buy too much, maybe because of in-store promotions, and maybe we cook too much and don't actually finish it. And maybe we even reject food with cosmetic flaws, and we probably misunderstand best before dates.

SPEAKER_01 11:49

Exactly. And let's be honest, sometimes it's just preference. We decide that we rather eat pizza instead of yesterday leftovers.

SPEAKER_02 11:59

So let's find out from Jessica why food waste happens so often at home.

SPEAKER_01 12:06

Even when people genuinely want to avoid it.

SPEAKER_00 12:09

Food waste is a complex problem. And of course, a lot of things in life are complex, um, so it maybe holds to a lot of stuff. Um, but I would argue that food waste is even more complex, and that is because um when one looks at food, food waste, cause and effect can be at different stages of the supply chain. So if you envision there's some producer in Italy deciding should we put um a best date label, should we put it after three months or after six months? Um, that is sort of months before a consumer is in the kitchen and opening a cupboard and deciding, oh, I have to throw it out. It's it's past the date. So the cause and effect and food waste is often at different places in the supply chain. So that's one reason why it's complex. The second reason is because with all food choices, there's a lot of different people involved. So there might be one person making the shopping list, another person is going shopping, a third person is doing the shopping saying, Oh, I want this, I want this. And then there's a fourth person maybe that is saying, Oh, no, today I'm not going to eat. Um, I have an appointment with a friend, so I'm leaving. Um, and then too much has been cooked. And then there's another person putting stuff in the freezer, but not putting some any indication of what it is on the frozen product. So um, yet another person is maybe taking it out of the freezer and doesn't know what it is, so it gets lost um after being frozen. So there's the third reason the second reason why food waste is so complicated is because people, there are different people involved. And then also the food because there's so many needs involved. So everybody has a motivation, nearly everyone has a motivation to not waste food. I mean, nobody goes and buys some eggs in order to trash them. So everybody has a motivation to not waste food. But how strong that is and how much that interacts with other reasons, um, you want to eat house, so you buy a lot of fruit and vegetables, but they don't get to use it, so you have to you have to throw something out. So there's multiple needs involved, um, including, for example, that you don't want to waste food, but you also want to make sure that everybody at home enjoys the meal. And um, not that many people enjoy having a lot of leftovers, so having to combine a lot of leftovers. So there's always a lot of trade-offs between different goals at home that lead to food waste in the end.

SPEAKER_01 14:27

Well, Gretchen, it's definitely more complex than I thought.

SPEAKER_02 14:30

It's not only about carelessness, it's also about routines. Different people in the household, confusion about date labels, and many trade-offs people make in daily life. Let's next find out what we can do about food waste.

SPEAKER_01 14:51

The good news is there are simple solutions. At home, we can plan meals and shop with a list, store food properly, and use leftovers creatively. Understand labels and freeze food you can't eat right away.

SPEAKER_02 15:07

Yeah, those are great ideas. And at a broader level, supermarkets and restaurants can donate surplus food. There are apps, like Too Good to Go that make it easy for consumers to buy leftover meals cheaply. And couldn't governments also introduce campaigns and set some targets?

SPEAKER_01 15:30

I really wonder what we can do to help, both at home and at the broader level, if we want to reduce food waste in a meaningful way.

SPEAKER_00 15:39

A practical thing for individuals in order to address food waste is actually rather boring. Because um, like with a lot of things in life, if you're getting better in planning and organizing, you can also reduce food waste. And I think some studies really show, I mean, if you do a shopping list and you kind of check your fridge before you go shopping, and if you've been bought too much, you kind of remember, okay, I have some slices of bread before they start getting moldy, I'm freezing it. Um, and then you also take it out of the freezer early enough again. Um, so it's simply planning and organizing that again and again shows up as one of the um things that individuals can do in order to reduce food waste. The more effluent we are, the less the more food we waste. Simply because food doesn't play that much a role in our budget, so we can more easily waste it. When I started doing research about food waste, I did some interviews, and it really stuck with me that one expert was saying, well, if we have a crisis, I mean the food waste problem is kind of going away because people don't have enough money, so they don't uh waste food. And they so there is there is a relation between prices and and food. Then, of course, if one considers this, that people more likely waste something if they can afford it. Um one thinks about okay, why do then retailers reducing the price of food in order to sell it when it's getting closer to the date? But of course, there's a difference between the food that you have in your home and the food that you're gonna buy. Um whether you already have paid for it and whether you have not paid for it, that makes a difference. And actually, the retailers reducing the price of food the closer it gets to the date, is really working well. So a lot of retailers are doing that, and I think it's also really, really useful. Um, it gets more useful if they can do it less manually and more automatic. So if they actually use a lot of data knowledge and sort of automatically changing um price labels instead of having the personnel going around and checking food and putting new labels and stickers on it. Um so I think that is a really powerful tool to reduce the price the closer the product gets to the date. It's also fair to people because I think people shouldn't feel like they they they are in the store and then the store is telling you, oh, could you rather take the milk that is in the front? I mean, I mean, if somebody wants the milk that lasts for longest, I mean that's okay because they are paying the price. And if they take the milk that is uh expiring tomorrow um and then it costs less, it's it's really nice because they're actually um getting also less value out of it. So I think this is really important. So the combination of reducing the price and the retailers and also having um using a lot of data in order to be sure that they know which product to reduce in price when and also how much people use at which point in time. I think this combination can be a really powerful tool. In addition to that, I think also communicating to customers about what they do and why, so that people understand it and are on board with it and also think it's good and um also give value to the retailer by actually acknowledging that. And and uh that are these three things I think really important for retailers. Policymakers can make it easier or require um retailers to do certain things. They can sort of simply require retailers to do certain things, like donating um food. Um they can change some of the legislation in order to allow it or make it easier for retailers to do certain changes, which are maybe not allowed because some legislation for food safety is not making it possible. And I think there's also a lot of work done in the EU about harmonizing food waste measurements because it's still not harmonized enough to really know what exactly works in which way. But it's only working with the symptoms, it's not working at the source of the problem. So I think the initiatives that don't require the food to be moved somewhere else to then be distributed from somewhere else to poorer people. I think it's much better if it if the food waste doesn't even it is not caused in the original retailer, if it can be sold at the same place. I think that would be much better because it saves the resources of redistributing um stuff to somewhere else. The scenarios actually show that reducing food waste alone is not enough, changing our diets to more plants is also not enough. So it is actually combining these two, and I think there was always a third thing in those studies, but it's um just food waste and just dietary transition alone is is not enough. So both of these are actually relevant. A lot of these topics they differ throughout your life stages and um motivations and and what people do change over time. Um and that is sort of there's natural life stages like having a baby, getting into a certain age, and that influences often what people do and think about health and sustainability. There's also life stages like, for example, you see a documentary about animal welfare and suddenly you turn vegan. So these kind of things, and this is often when one thinks about change of people's behavior, it's often a good opportunity for change because people are sort of have a strong motivator that can be because they got sick and or because they've seen something that really moves them emotionally, um, or also life stages like you move out from your parents, so you have to figure out your own household. So life stages is a really important element of changing behaviors.

SPEAKER_01 21:21

So, to recap, reducing food waste clearly needs action at more than one level.

SPEAKER_02 21:27

Planning and organizing better at home certainly can help.

SPEAKER_01 21:32

But impactful change also depends on retailers, policymakers, and wider efforts across the food system.

SPEAKER_02 21:39

And importantly, food waste reduction works best alongside other dietary changes, not simply on its own.

SPEAKER_01 22:00

Some great insight from our expert, and the good news is that small actions really do add up. And here are three quick tips to make a difference starting today. Tip 1. Plan before you buy. Check what's already at home and make a short list before going shopping. Tip two. Rotate your fridge like a pro. Move the older food to the front. Like pretend you're running a tiny grocery store. And make sure nothing gets forgotten in the back. And tip three, get creative with the leftovers. Soups, stir-fries, even sandwiches are perfect ways to give extra food a second life instead of throwing it away. Yeah, and personally, I used to waste more than I thought. Once I started planning just little, checking the fridge before shopping or freezing extra portions, my food waste dropped almost overnight. And it actually felt good. Like a small step that connects what I do at home to something bigger. Something that matters for the planet as well.

SPEAKER_02 23:18

Oh, exactly. Reducing food waste doesn't require perfection, only a little bit of awareness and a few small habits that can stick.

SPEAKER_01 23:29

So if there is one thing to take away from today, is that every saved meal counts, Gretchen. Food waste is one of the simplest, most powerful things we can tackle for sustainability. Remember, one third of all food is wasted. That's third of resources, money, and nutrition lost.

SPEAKER_02 23:58

So here's a challenge for this week. Before going shopping, open your fridge and plan a meal around what you already have. You'll save money and food and the planet.

SPEAKER_01 24:18

This episode of Healthy People, Healthy Planet was written, hosted, and produced by me, Adam Fogaresi, and me, Gretchen Rapaski.

SPEAKER_02 24:29

Audio engineering by Periscope with support from the Danish Diabetes and Endocrine Academy. If you like what you heard, leave us a review and get in touch. Our email is in the show notes. Thanks for listening.