Switching to more environmentally friendly food and drink alternatives could slash greenhouse gas emissions from household groceries by more than 25 percent, according to a new study from The George Institute for Global Health and Imperial College London. Published in the journal Nature Food, the research suggests that even more substantial changes, such as choosing vegetarian options over meat-based ones, could cut emissions by as much as 71 percent.
The study highlights the need for on-pack labeling of greenhouse gas emissions for all packaged food products, enabling consumers to make informed choices. This analysis, the most comprehensive of its kind, evaluates the environmental impact of a country’s food purchasing behavior using extensive data on greenhouse gas emissions and sales of thousands of supermarket products, reflecting the Western diet prevalent in many countries.
Dr. Allison Gaines, lead author and epidemiologist at The George Institute and Imperial College London, emphasizes the necessity of changing dietary habits to meet global emissions targets, especially in high-income countries.
“Dietary habits need to change significantly if we are to meet global emissions targets, particularly in high-income countries like Australia, the UK, and US. But while consumers are increasingly aware of the environmental impact of the food system and willing to make more sustainable food choices, they lack reliable information to identify the more environmentally friendly options,” Gaines says.
Researchers used the FoodSwitch database and global environmental impact datasets to calculate the projected emissions of annual grocery purchases from 7,000 Australian households. They assigned over 22,000 products to major, minor, and sub-categories of foods to quantify emissions saved by switching within and between groups. Findings showed that switching within the same sub-categories could lead to a 26-percent reduction in emissions in Australia, equivalent to removing over 1.9 million cars from the road. Switching within minor categories could push this reduction to seventy-one percent.
“The results of our study show the potential to significantly reduce our environmental impact by switching like-for-like products. This is also something consumers in the UK could, and would probably like, to do if we put emissions information onto product labels,” Gaines says.
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Gaines also notes that such switches would not compromise the healthiness of food. “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 says.
The analysis revealed that meat products contributed nearly half of all greenhouse gas emissions but accounted for only eleven percent of total purchases. Conversely, fruits, vegetables, nuts, and legumes made up 25 percent of purchases but only five percent of emissions.
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Globally, the food and agriculture sector is responsible for about one-third of greenhouse gas emissions, with combined health and environmental costs estimated at 10-14 trillion USD per year. Transitioning to healthy, low-emission diets could prevent more than 12 million deaths annually.
Bruce Neal, Executive Director at The George Institute Australia and Professor of Clinical Epidemiology at Imperial College London, warned of the slow progress in improving the food system’s sustainability.
“There is currently no standardized framework for regulating the climate or planetary health parameters of our food supply, and voluntary measures have not been widely adopted by most countries. This research shows how innovative ways of approaching the problem could enable consumers to make a real impact,” Neal says.
To aid consumers, The George Institute has developed a free app called ecoSwitch, available in Australia, which allows shoppers to scan product barcodes to check their Planetary Health Rating, ranging from half a star (high emissions) to five stars (low emissions). The Institute plans to expand the ecoSwitch algorithm to include other environmental indicators and introduce it to other countries.
“While ecoSwitch is a much-needed first step in providing environmental transparency for grocery shoppers, the vision is for mandatory display of a single, standardized sustainability rating system on all supermarket products,” Neal says.
