Adopting more sustainable eating habits can significantly contribute to combating climate change and alleviating global food scarcity. However, implementing these changes on a global scale presents its challenges.
“Demand for food in one region can create ripple effects that impact the environment and human well-being worldwide,” explained Joe DeCesaro, a data analyst at UC Santa Barbara’s National Center for Ecological Analysis & Synthesis (NCEAS).
Despite the intricate nature of the global food system, shifting diets is essential for ensuring a healthy planet and population. Aiming to clarify some uncertainties related to this complex yet essential task, DeCesaro and a team of international researchers investigated how environmental pressures might be affected by shifting to four different dietary patterns: Indian, Mediterranean, EAT-Lancet (which is primarily plant-based or “flexitarian”), and the average government-recommended food-based dietary guidelines (FBDGs). Among these, the Indian diet proved to be the most advantageous, potentially reducing global environmental pressures from food production by approximately 20.9%. In contrast, the FBDGs might lead to a 35.2% increase in global environmental pressures.
The findings of this research were published in the journal Environmental Research Letters.
Understanding Food Flow
The global food system is a leading cause of environmental change, accounting for around one-third of global greenhouse gas emissions and utilizing over 70% of freshwater resources. Additionally, this system leads to land degradation due to agriculture and contributes significantly to nutrient pollution in oceans and rivers. Therefore, adopting a sustainable diet—one that prioritizes less resource-heavy foods, such as vegetables and legumes over red meat—can alleviate environmental strain and promote better health, especially if it involves reducing refined sugars and starches.
However, this is just one piece of the puzzle, as the researchers point out.
“We aimed to find out who will actually experience the effects of food production if these dietary changes take place,” said Ben Halpern, NCEAS director and coauthor of the study. There has been a lack of understanding regarding how environmental pressures might shift or if new pressures could arise as a result of significant dietary changes, especially since food is often produced in one region and consumed in another.
“The underlying question driving this research was: Who is causing the environmental pressures associated with food production that affect people globally?” DeCesaro noted. “Are poorer nations bearing the environmental weight of producing resource-intensive foods for wealthier countries, or is it the other way around? Our methods enable us to trace changes in environmental pressures from producers to consumers and vice versa, uniformly across four types of pressures.” This approach is quite innovative in this field.
Utilizing various data sources, including average diets by country, trade flows, and the environmental impacts of food production, the researchers effectively mapped the changes in environmental pressure associated with a global switch to each of the four diets: the mostly vegetarian Indian diet, the plant-centric Mediterranean and EAT-Lancet diets, and average government-recommended dietary guidelines.
“The four dietary scenarios we chose provided a good variety of dietary patterns, from low to high meat consumption, while also maintaining cultural relevance,” DeCesaro remarked. “The Indian diet and FBDGs reflect government guidelines, the Mediterranean is renowned for its health benefits, and the EAT-Lancet diet is crafted by experts in the field.”
They discovered that adopting three of the four diets studied—all except the FBDGs—would lead to a decrease in global environmental pressures. Particularly, the Indian diet excelled mainly due to its virtually non-existent red meat consumption, whereas the FBDGs typically suggest a greater intake of red meat than many countries currently consume.
Significantly, reductions in global pressures would primarily stem from dietary changes in wealthier countries, according to the study.
“The current average diets in high-income nations contain larger quantities of most food categories than those recommended in our scenarios,” DeCesaro mentioned. “Essentially, these nations tend to overconsume compared to our dietary recommendations, while low-income nations are generally under-consuming these food categories.”
Moreover, if there were a global shift towards more sustainable, plant-centric diets, low-income countries would likely see an increase in environmental pressures related to food production. DeCesaro explained that this is mainly because these diets would better meet their daily nutritional needs. To achieve food security and ensure fair access to nutritious food in these regions, the authors advocate for support from wealthier nations through improved access to efficiently produced food imports, economic development to enhance dietary health and mitigate environmental pressures associated with food production, and sharing knowledge of efficient and sustainable food production methods.
“Exchanging sustainable agricultural practices will help mitigate any rises in environmental pressures resulting from dietary alterations,” DeCesaro stated. Continuing this line of research, the team is analyzing current food trade trends and the environmental impacts associated with them, regardless of any dietary shifts.
“A critical takeaway from our research,” Halpern concluded, “is that our food choices significantly affect our environmental footprint, and those decisions may impose costs on other communities around the world.”
