These are the UK supermarket items with the worst environmental impact

Researchers trained an algorithm to estimate the environmental impact of 57,000 products sold in the UK and Ireland to help consumers make environmentally friendly choices


August 8, 2022

JE4DFK Beef, beef and pork raw meat fridge in Sainsbury's supermarket, East Sussex, UK

Meat has a greater environmental impact than most other products in the supermarket

EW Brown/Alamy

Avoid the supermarket aisles piled high with cheese, quiches and pies. That’s the message of an analysis which found they fare worst in terms of nutritional quality and environmental impact among thousands of food and drink products sold in the UK. And if your priority is to reduce carbon emissions and water use, also avoid the meat and fish shelves.

So far, most studies assessing food’s environmental footprint have focused on the impact of agricultural commodities such as beef or soy, rather than the lasagna, tofu and other products that shoppers often purchase. Where research has focused on consumer products, it has usually been for a small number of them.

In an attempt to bridge the gap, Michael Clark of the University of Oxford and his colleagues analyzed more than 57,000 food and drink products sold in the UK and Ireland. The team took the ingredient data from eight retailers, including major supermarkets Tesco and Sainsbury’s.

However, exact figures on how much of each ingredient in each product were only available for around a tenth of them. To estimate the rest, Clark and colleagues trained an algorithm on the known products and used it to predict the composition of the unknowns, helped by the fact that British regulations mean ingredients must be listed in descending order of quantity. Finally, the team linked all the ingredients to an existing database of environmental impacts, including emissions, land use and water stress.

The results may come as no surprise: meat, fish and cheese products had the greatest environmental impact. Desserts, pastries and savory pies came next. Fruit, vegetables, bread and sugary drinks had the lowest load. For the most part, there was an overlap between low environmental impact and good nutrition, a further analysis showed.

Clark admits that none of this is surprising, given what we already knew from previous research. “The big advance is not that beef has a high effect, fish has a high effect, cheese has a high effect. It’s the fact that you can start to get these effect estimates for products that people buy, which then has a lot of implications,” he says.

One of these is eco-labels, which a growing body of evidence shows can guide consumers to make greener choices. However, retailers have previously struggled with the scale of the challenge. In 2012, Tesco stopped trying to add carbon labels to all its products because it would take centuries to assess them all at the rate they were able to.

Clark’s approach shows the way to do such labeling on a large scale. He’s thinking about how he can eventually turn the data into an app that can be used either by buyers or by retailers who want to reduce their environmental impact. “We’ve made that information available in a way that means people can start making informed decisions,” he adds.

The main limitation of the new research is that it does not take into account different sources of the same ingredients, such as beef produced in the UK or imported. For example, according to the UK Climate Change Committee, UK beef emissions are 14 per cent lower than the EU average.

“The paper provides a lot of value by making the environmental impacts of food more tangible and actionable for consumers,” says Hannah Ritchie of Our World in Data. “Previous studies mostly focus on the effects of broad food categories – such as corn, wheat or legumes.” She believes the study is a step towards environmental labels in supermarkets.

Journal reference: PNASDOI: 10.1073/pnas.2120584119

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