The truth about processed foods’ environmental impact

It’s becoming increasingly difficult to ignore how our eating habits are damaging the planet.

Our food system affects groundwater supplies, generates a third of the world’s greenhouse gas (GHG) emissions, and uses up a lot of land, which involves converting natural ecosystems and causes a loss of biodiversity.

In response, scientists advise we cut down on meat, reduce food waste and buy more locally produced food. But would the planet also benefit from us eating less processed food?

Food can be divided into unprocessed or minimally processed, processed, and ultra-processed. Ultra-processed food, such as chips and cake, accounts for just over half of the calories we consume. 

Unprocessed, locally sourced foods, such as whole fruits and vegetables, have a relatively low carbon footprint. Research has also found that minimally processed vegetarian foods have among the lowest environmental impact.

But buying minimally processed food – such as dried fruit, sliced or frozen vegetables or pre-cooked rice – might actually result in fewer emissions than buying unprocessed fruit and vegetables and adding in this step at home. That includes chopping and freezing, not just cooking.

“One needs to look at how processing adds a step that you’d otherwise do,” says Marco Springmann, senior researcher on environmental sustainability and public health at the University of Oxford.

“If you processed some food at home, the chances are you expend more energy doing that, as the process isn’t as streamlined as a big factory.”

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What about all the resources and energy needed to make all the ingredients in ultra-processed food? The sustainability of a food depends on how much energy goes into processing, storing, preserving and refrigerating it, and how much of it we waste, says Shelie Miller, associate professor at the University of Michigan’s School for Environment and Sustainability.

“It’s therefore the type of ingredient, rather than number of ingredients, or whether it’s processed or not, that drives the environmental impact of a food,” she says.