Researchers have developed a new way of assessing supermarket products.
A study estimating the environmental impact of 57,000 food items in the UK and Ireland has been published by an Oxford-led research team.
It looked at things like greenhouse gas emissions, land use and water stress, with researchers saying that until now, there was no way of directly comparing impact on the environment.
They developed an algorithm that estimated the percentages of all ingredients within each food.
Multi-ingredient products made of fruits, vegetables, sugar, and flour, such as soups, salads, bread and many breakfast cereals, have low scores, and those made of meat, fish and cheese, are at the high end of the scale.
The paper found meat alternatives, such as plant-based sausages or burgers, had a fifth to less than a tenth of the environmental impact of meat-based equivalents.
Jerky, biltong, and other dried beef products, which typically have more than 100g of fresh meat per 100g of final product, often have the highest footprints.
Products that were more sustainable also tended to be more nutritious, including meat and meat alternatives - but with the exception of sugary drinks.
The researchers say it's a first step towards helping consumers, retailers, and policymakers to choose more sustainable and healthy food and drink in the shops.
Lead author, Dr Michael Clark says: "By estimating the environmental impact of food and drink products in a standardised way, we have taken a significant first step towards providing information that could enable informed decision-making.
"We still need to find how best effectively to communicate this information, in order to shift behaviour towards more sustainable outcomes, but assessing the impact of products is an important step forward."
A recent study by the Food Standards Agency showed that more than half of UK consumers want to make more sustainable decisions on the environmental impacts of foods and, at the same time, food corporations are setting ambitious net zero greenhouse gas targets.
But the team from Oxford's Livestock, Environment and People programme (LEAP) says there is a lack of detailed environmental impact information on food and drink products, which would allow consumers and corporations to make better choices.
A limitation of the analysis is that information on ingredient sourcing, such as country of origin or agricultural production method, is lacking from ingredient lists.
Researchers say this would help increase accuracy of the environmental impact estimates. Portion sizes also vary for different products leading to more uncertainty.
The analysis made use of foodDB, a big data research platform at Oxford Population Health that collects and processes data daily on all food and drink products available in twelve online supermarkets in the UK and Ireland, and a comprehensive review of 570 studies of the environmental impact of food production, which includes data from 38,000 farms in 119 countries.
Dr Richie Harrington, senior author for this paper and lead researcher for foodDB said: "Our method fills an information gap on the environmental impacts of multi-ingredient foods.
"The algorithms we developed can estimate the percentage contribution of each individual ingredient within a product and match those ingredients to existing environmental impact databases. We have illustrated how this can be used to derive quantifiable insight on the sustainability of food products, and their relationship to their nutritional quality."