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Shifting our diets toward more sustainable options has been proposed as a powerful solution to both climate change and global food insecurity. However, making such changes at a global scale could lead to unintended consequences that affect people worldwide, according to a new study published in Environmental Research Letters.
Joe DeCesaro, a data analyst at the University of California, Santa Barbara’s National Center for Ecological Analysis & Synthesis (NCEAS), explained that while changing food habits in one region can have positive environmental outcomes, these shifts can also trigger cascading effects elsewhere. “Changes in food demand in one part of the world can have cascading environmental and human welfare implications for people around the world,” DeCesaro said.
The study, led by DeCesaro and an international team of researchers, delves into the environmental consequences of adopting one of four potential diets: the Indian diet, the Mediterranean diet, the EAT-Lancet diet (largely plant-based), and the average government-recommended food-based dietary guidelines (FBDGs). These diets were chosen to explore how changes in food consumption could impact global environmental pressures, including greenhouse gas emissions, water use, and land degradation.
The Environmental Benefits of Shifting Diets
The findings highlight some surprising outcomes. The Indian diet, primarily vegetarian and low in meat, emerges as the most environmentally beneficial, with an estimated 20.9% reduction in food production-related global environmental pressure. This is primarily due to its lack of red meat, which is highly resource-intensive to produce. On the other hand, the FBDGs, which tend to recommend more meat than is typical in many countries, could lead to a significant 35.2% increase in global environmental pressures.
The study also underscores the importance of dietary changes in wealthier countries, where overconsumption of resource-intensive foods is common. “Higher-income countries’ average diets consume more food than the recommended quantities in our diet scenarios,” DeCesaro noted. Shifting these diets could reduce environmental impacts significantly, while also improving public health outcomes.
The Social Costs of Sustainable Diets
While the environmental benefits of shifting diets are clear, the social implications are more complex. One of the central questions the researchers sought to answer was: Who will bear the costs of these changes?
“Are poorer countries paying the environmental price of producing higher pressure foods that are being eaten by richer countries, or vice versa?” asked Ben Halpern, director of NCEAS and a coauthor of the study. The answer lies in the global trade system, where food is often produced in one part of the world and consumed in another. The researchers used detailed data on food flows, trade patterns, and environmental impacts to trace how dietary changes would affect both producers and consumers across the globe.
In higher-income countries, dietary shifts toward plant-based options would likely reduce environmental pressures, as these regions currently consume more than the recommended amounts of meat and dairy. However, lower-income countries, which tend to consume less, could face an increase in food production-related environmental pressures as they meet the nutritional needs of their populations.
“The shift toward more sustainable, plant-forward diets could cause an increase in environmental pressures for lower-income countries, but this would be mainly because the diets would better meet their daily nutritional needs,” DeCesaro explained. This dynamic raises concerns about the potential negative impacts on these countries, especially given their limited resources for sustainable food production.
A Call for Global Cooperation
To mitigate these pressures, the study authors advocate for increased support for low-income nations, particularly in the form of efficient food production practices, better access to imports of sustainably produced foods, and economic development initiatives that could improve dietary health and reduce environmental burdens.
“Sharing sustainable agricultural practices will help reduce any increases in pressures seen from diet shifts,” said DeCesaro. By promoting global knowledge-sharing on efficient food production, wealthier countries can help reduce the environmental costs of dietary shifts in poorer regions.
The researchers are also exploring how current food trade patterns contribute to environmental pressures, without any changes in global diets, in order to gain a fuller understanding of these dynamics.
A Message for the Future
The study ultimately sends a powerful message about the interconnectedness of food, environment, and society. “The decisions we make about what we eat are important for reducing our environmental footprint,” said Halpern. “But other people may pay the price for those decisions.”
As the world grapples with both climate change and food security, understanding the hidden costs of our diets—and how they ripple through the global system—will be crucial in making sustainable choices that benefit both the planet and its people.
