Food swaps

Simple food swaps could cut greenhouse gas emissions from household groceries by a quarter

Switching food and drink purchases to very similar but more environmentally friendly alternatives could reduce the greenhouse gas emissions from household groceries by more than a quarter (26%) according to a new Australian study from The George Institute for Global Health and Imperial College London published today in Nature Food1.

Making bigger changes - like swapping a frozen meat lasagne for the vegetarian option - could push the reduction to as much as 71%.

To make this happen will require on-pack labelling of greenhouse gas emissions for every Australian food so that consumers can make informed choices.

This is the most detailed analysis ever done on the environmental impacts of Australia’s food purchasing behaviour, involving comprehensive data on greenhouse gas emissions and sales for tens of thousands of products sold in supermarkets.

Lead author and epidemiologist, Dr Allison Gaines, who conducted the analysis for The George Institute and Imperial College London, said, “Food and beverage consumption patterns, particularly in higher-income countries like Australia, need to change significantly if we are to meet global emissions targets.

“But while consumers are increasingly aware of the environmental impact of the food system and willing to make more sustainable food choices, they have lacked reliable information to identify the more environmentally friendly options.”

Researchers calculated the projected emissions of annual grocery purchases from 7,000 Australian households using information on ingredients, weights and production life cycles in The George Institute’s FoodSwitch database and global environmental impact datasets. More than 22,000 products were assigned to major, minor, and sub-categories (e.g. ‘bread and bakery’, ‘bread’ and ‘white bread’, respectively) to quantify emissions saved by switching both within and between these groups.

Meat products contributed almost half (49%) of all greenhouse gas emissions, but only 11% of total purchases. Conversely, fruit, vegetables, nuts and legumes represented one quarter (25%) of all purchases, but were responsible for just 5% of emissions. 

In total, just over 31 million tonnes of food-related greenhouse gas emissions were attributable to products consumed in Australian homes in 2019 – equivalent to emissions from more than six million cars driving for an average of 22,500km per year2.

“The results of our study show the potential to significantly reduce our environmental impact by switching like-for-like products. This is something consumers could, and would probably like, to do if we put emissions information onto product label,” said Dr Gaines. 

Dr Gaines added that the switches would not compromise food healthiness overall: “We showed that you can switch to lower emissions products while still enjoying nutritious foods. In fact, we found it would lead to a slight reduction in the proportion of ultra-processed foods purchased, which is a positive outcome because they’re generally less healthy,” she said.

It is estimated that around one-third of global greenhouse gas emissions are attributable to the food and agriculture sector3, and the combined health and environmental costs of the global food system are estimated to be 10-14 trillion USD per year4,5. More than 12 million deaths per year could be prevented if the system transitioned to deliver healthy, low-emission diets3.

In an editorial published today in the Australia and New Zealand Journal of Public Health6 Professor Simone Pettigrew, Program Director, Food Policy at The George Institute for Global Health, said Australia is taking too long to improve the sustainability of the food system, endangering the prospect of a net-zero future7.

“There is currently no standardised framework for regulating the climate or planetary health parameters of our food supply, but by using studies like this, we can develop innovative ways to help consumers make informed choices and create a movement for positive change,” she said. 

“With this in mind, we have developed a free app called ecoSwitch, which is based on this research. Shoppers can use their device to scan a product barcode and check its ‘Planetary Health Rating,’ a measure of its emissions from half a star (high emissions) to five stars (low emissions).”

The George Institute also plans to extend the ecoSwitch algorithm to integrate other environmental indicators such as land and water use, and biodiversity, and to introduce the tool to other countries.

“Incorporating environmental sustainability indicators into packaged food labels is another measure that could help consumers make more informed purchases and encourage manufacturers to produce products with lower emissions,” added Prof. Pettigrew. “Our vision is for a single, standardised sustainability rating system to bring transparency to the environmental impact of packaged foods.”

Download ecoSwitch: 

ecoSwitch Australia - Android 

ecoSwitch Australia - iOS

About the analysis:

Grocery purchase information from the 2019 NielsenIQ Homescan Consumer Panel dataset captures all product purchases consumed at home by participating Australian households from January to December each year. These were linked to the 2019 FoodSwitch database to assess product nutrition information, Health Star Rating, NOVA score (level of industrial processing) and greenhouse gas emissions (GHGe). Product-specific GHGe values were estimated primarily on the basis of ingredient life cycles using the cradle-to-farm gate system and the Ecoinvent 3.7.1 and Agri-footprint 5.0 databases, which assign estimated GHGe for individual ingredients. The ingredient GHGe values were then weighted by ingredient proportions and totalled to estimate each product’s GHGe value.


  1. Gaines A, et al. Switches in food and beverage product purchases can reduce greenhouse gas emissions in Australia. Nature Food 2024.
  2. United States Environmental Protection Agency. Greenhouse Gas Equivalencies Calculator. Accessed May 2024.
  3. Romanello M, et al. The 2023 report of the Lancet Countdown on health and climate change: the imperative for a health-centred response in a world facing irreversible harms. The Lancet. 2023;402(10419):2346–94
  4. Laderchi RC et al. The economics of the food system transformation. Oslo, Norway: Food System Economics Commission; 2024
  5. Lucas E, Guo M, Guillén-Gosálbez G. Low-carbon diets can reduce global ecological and health costs. Nat Food. 2023;4(5):394–406
  6. Pettigrew S, et al. Sustainable diets: Empowering consumers in the face of regulatory tardiness. Australian and New Zealand Journal of Public Health 2024.
  7. Australia joined more than 160 other jurisdictions in signing the UAE declaration on sustainable agriculture, resilient food systems, and climate action at the United Nations’ Climate Change Conference (COP28), Dec 2024