People who eat more sausages, burgers and other ultra-processed foods at least double the daily damage they do to the environment, warn scientists.
Junk food sends greenhouse gases soaring, strips forests and hoovers up huge amounts of water, says a long-term study of diet trends.
For a decade, we’ve known eating lots of processed foods is bad for our health with links to obesity, heart disease and cancer. But until now we’ve been clueless about what these foods do to the planet.
“Changes in the way we used to eat, for example less home cooking and seasonal eating, are deteriorating our health and contributing to the climate crisis,” said Brunel sustainability expert, Dr Ximena Schmidt.
“This study shows for the first time how increasing the consumption of foods like burgers, sausages and other ultra-processed products has produced more greenhouse gas emissions, and used more water and land, even in developing countries like Brazil.”
The 30-year study of Brazil’s diet trends in the Lancet Global Health, is the first to hammer home how a country’s eating habits affect its impact on climate change.
Britain had a similar diet change over the past century and experts reckon that as economies grow, developing countries will eat more processed foods, mostly meat, which could set them back on climate change targets.
Researchers from University of São Paulo, Brazil, Brunel University London, City, University of London, the University of Manchester, the University of York and the University of Sheffield calculated the environmental footprint of different foods per 1,000 calories. They looked at unprocessed foods, processed ingredients, processed foods and ultra-processed foods - things with artificial additives like sweeteners, preservatives and flavours.
Eating ultra-processed meat at least doubles the amount of daily damage a person does to the environment. This means that ultra-processed meat is responsible for up to 20% of the environmental impact of diets.
For every 1,000 calories, these foods were linked to a 21% increase in national greenhouse gas emissions, 22% increase in the nation’s water footprint and 17% increase in ecological footprint.
"The relationship between food systems and climate change is complex and challenges food security itself,” said University of São Paulo nutritionist Jacqueline Tereza da Silva. “Food systems are responsible for a third of global greenhouse gas emissions, and yet, at the same time, they suffer from the climate impacts that they themselves help to cause."
Dr Schmidt adds: “People need to become more conscious of what they eat if we want to protect the environment and live healthy lives. We need to start thinking that impacts to the environment and health need to be tackled together.”