When research influences reality, it can change the world

25 February 2022

Dr Tom Quested is the lead analyst at WRAP and has spent most of his 13 years with WRAP researching the causes and effects of food waste. Dr Rachel Devine joined WRAP as an analyst 3 years ago and leads on the data analysis and reporting for our Courtauld Commitment 2030 voluntary agreement.

two people talking over Zoom

Here, the two researchers take a look behind the team’s work on the recently published research on uncut fresh produce. This radical piece of work adds new perspectives on our relationship between plastic packaging and food waste, and the influence of date labels on consumer behaviour. They explain how it was put together, their excitement at challenging the status quo, and the importance of making decisions guided by facts and not assumptions.


Tackling food waste and plastic pollution are two of the most pressing environmental challenges of our lifetimes – both contribute to climate change and cause serious damage to our ecosystems.

One of the barriers to removing plastic packaging from items was a belief that this could lead to more household food waste. Conversely, selling some fresh produce loose could actually reduce food waste by enabling people to buy the quantity they need.

Until now, there has been a substantial evidence gap in understanding, which has blocked progress. In an extensive 18-month project, the WRAP team took five items of uncut fresh produce and combined household simulation modelling, shelf- life experiments on packaged versus loose food items, and in-depth consumer research around date labels. We believe it is the first time this approach has been taken.

A comprehensive picture emerged which challenges the status quo. Our findings show that selling loose has huge potential to reduce food waste in our homes. We found that storing food in the fridge below five degrees can give more quality product life and that plastic packaging made little or no difference to shelf life. We also strengthened our existing evidence that people are swayed by date labels, causing them to throw food away while it is still good to eat.

It led to three main recommendations:

Three recommendations for industry: Sell loose, remove date labels and provide best practice guidance on storage (at home, store below 5°C).
Q: What was the starting point for this important piece of work?

Rachel: There are several different functions to plastic packaging – it can stop food from being damaged; it allows, or encourages, people to buy a certain size of pack; there’s a date label on it. There was some evidence to suggest that the packaging might extend the shelf life of the food. But it was limited. We needed to know how all these elements interacted; so future action would be rooted in hard evidence.

We needed to establish the extent to which removing plastic packaging on fresh produce items actually influences food waste in the home. We are driving two major pieces of work at WRAP through our partners – reducing food waste and plastic packaging. Without that knowledge it felt like those two agendas were butting up against each other.

Q: What were the big surprises?

Tom: At the start of the project, there was great uncertainty about which packaging we should suggest removing, and which should be staying on the products because of the perceived risk of food waste. So, we picked a range of items to explore: some where we initially thought the packaging would help reduce food waste in the home, and some where the packaging would exacerbate food waste.

The surprise was that we didn't find the balance where we thought it would be. The 'shelf-life extending properties' of packaging were much less than we anticipated. This unexpected finding is behind the recommendation that most packaging from fruit and vegetables could be removed; enabling people to buy an amount of food appropriate to their needs.

Rachel: The other big surprise was how much it strengthened our conviction about how people are influenced by date labels to dispose of food whilst it was still good to eat.

In previous research we had just asked people to what extent they rely on date labels. However, we suspected that some people would respond in a way that was, to them, most socially acceptable. This time, we took a different approach and investigated their gut reaction.

So, for example, we showed some people a picture of a banana in good condition without a date label, and another group the same picture with a date label. We then asked all participants to make an instant decision on whether they would use the banana or throw it away, 14% of people said they would dispose of it if there was no ‘Best Before’ date. If there was a date label, the corresponding figure was 48%.

Q: How can you be so sure about the findings?

Tom: The approach – using our Household Simulation Model - is the closest we could get to actual household trials. We simulated the journey of food through different types of households using a wide range of input data drawn from many, many studies: how frequently people go shopping and how much they buy, the shelf life of products, how they store them, consumption patterns and disposal decisions. The Model allows us to see how all these factors interact and their influence on food waste.

For some of the input data, we already had good information at the start of the project: for example, consumption patterns of different products. Whereas, for other input data, like shelf life, we realised we didn’t have a good idea of how long products lasted or how much difference the packaging made. We’d all heard the example of the shrink-wrapped cucumber lasting three weeks longer, but we couldn’t find reliable, relevant data for cucumbers sold in the UK. That's why we commissioned the shelf life experiments. Another big unknown was around date labels, so again, we strengthened the research through commissioning citizen research into this specific topic.

So, early attempts at modelling helped us pinpoint important information that we didn't know, and commission the evidence gathering to improve these modelling inputs. That is what makes the research so robust.

Rachel: There’s always that moment during a research project when you find something that departs from popular view, when you ask yourself, ‘have we actually got this right’? But not only was I confident in the approach, but we have also involved so many different people, not only colleagues within WRAP, but externally. We’ve had our industry advisory group; so, we’ve sense checked the findings all along the way.

Tom: I would add that evidence in the public domain relevant to these research questions is thin. We’ve published results and details of the methodology, placing a big piece of the jigsaw in the public domain. However, it’s not the whole picture. The research community would benefit if a wider range of shelf-life experiments were conducted and published in full. This would allow us to understand the impact of packaging for, say, a wider range of apple varieties, sourced across the year.

“I believe that everyone has a responsibility to make important, world-changing decisions which are rooted in the right research. So, we’ve done the first, hard step, and now we have to support others to act on it.”

Q: How did it feel to work on this project?

Rachel: Being the first team to tackle the relationship between plastic packaging and food waste in this way; being at the forefront of new evidence which was going to unlock a barrier and be of huge relevance to so many different parties and on such important global issues is super exciting.

Because what we found goes somewhat against the grain of accepted wisdom, it’s also a bit daunting I must admit. But then you remind yourself that knowledge and thinking moves on, and there is sometimes a danger with holding onto a perceived truth just because it has been around a long time.

“There’s that moment in this project when we were thinking, 'we might be the only people in the world who know this right now'.”

Q: Is this why you enjoy the job you do?

Tom: At WRAP, there is an opportunity to conduct research which is going to directly inform decisions and actions that people, businesses, governments are taking to try and make the world a better place. That is tremendously rewarding. At WRAP, we have a team of experts who can interpret the work, make it accessible, and communicate it to stakeholders. It’s like a well-oiled machine swinging into action!

It is also incredibly interesting to explore these questions, developing our understanding and discovering, in this case, unexpected new things. There’s that moment in this project when we were thinking, “we might be the only people in the world who know this right now.”

Rachel: I left academia because I was motivated by the very real connection between the evidence WRAP provides and the conversion into action at scale. Which isn’t always the case with research in academic circles. I believe that everyone has a responsibility to make important, world-changing decisions which are rooted in the right research. So, we’ve done the first, hard step, and now we have to support others to act on it.

Q: What’s next?

Rachel: This is just the first step; we now have to promote and communicate the recommendations, and work with industry on how to turn it into a reality. We know it will be challenging to implement from a practical perspective – how to adapt stores for more loose produce; how to ensure it doesn’t push waste back down the supply chain. So, we want to help as much as we can. And with our voluntary agreements The UK Plastics Pact and the Courtauld Commitment 2030 we have the perfect mechanisms to work directly with businesses and help deliver the change needed at scale.

Tom: The Household Simulation Model can be applied to a range of other important, real-world problems relating to food waste. We’re already working with academic partners on different types of packaging, including refillable packaging, for a range of different products. And we’re looking at opportunities, both in the UK and in other countries, to investigate other aspects of food waste in the home.

It’s been a long journey to design, conduct and publish this work. There have been frustrations and challenges along the way, as there always are with important research, but we’re really proud of what we have accomplished. We believe it has the potential to be a real game-changer in tackling two of the most important environmental challenges on the planet.