Eating healthy can save money and significantly reduce greenhouse gas emissions compared to most people’s current dietary habits, according to a groundbreaking global study. Conducted by researchers from the Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts University, the study analyzed food costs, nutritional value, and climate impact worldwide. The findings, published in Nature Food, challenge the common belief that eco-friendly, healthy eating necessitates higher spending on premium products.
The research team identified locally available food items that meet basic nutritional needs while minimizing greenhouse gas emissions and monetary costs. They then compared these optimal diets with what people currently consume. “People can’t see or taste the emissions caused by each food, but everyone can see the item’s price—and within each food group, less expensive options generally cause less emissions,” stated Wiliam A. Masters, senior author and professor at the Friedman School.
Revolutionizing Dietary Choices for Sustainability
This study arrives as governments and international organizations seek ways to reduce food system emissions without exacerbating food insecurity. The research highlights a potential win-win scenario: adopting healthy diets that are both economical and environmentally friendly. Using the Healthy Diet Basket targets employed for global monitoring by U.N. agencies and national governments, the study aimed to identify the most sustainable foods to meet nutritional requirements.
The team examined three types of data for each food item: its availability and price in each country, its share of the national food supply, and the global average greenhouse gas emissions associated with it. They modeled five diets for each country: the healthiest diet with the lowest emissions, the healthiest diet at the lowest cost, and three variations based on commonly consumed foods.
Data-Driven Insights
Elena M. Martinez, one of the study’s lead authors, explained, “In general, choosing less expensive options in each food group is a reliable way to lower the climate footprint of one’s diet.” She added that the study extends this concept to extremes, identifying items that meet health needs with the smallest possible climate impact.
In 2021, a healthy diet using commonly consumed products emitted 2.44 kg of CO₂-equivalent emissions per person per day and cost a global average of $9.96. In contrast, a diet minimizing climate impact emitted only 0.67 kg and cost $6.95. A cost-minimizing healthy diet emitted 1.65 kg and cost $3.68. A blended scenario cost about $6.33 per day and produced 1.86 kg of emissions.
Challenges and Trade-offs
While the study shows that low-cost options often align with low emissions due to reduced fossil fuel use and land change, trade-offs exist in key food groups. Among animal-source foods, milk is often the cheapest option with lower emissions than beef, but fish like sardines and mackerel offer even lower emissions at moderate costs. In starchy staples, rice is often the cheapest but has higher emissions than slightly more expensive wheat or corn due to methane emissions from rice paddies.
Researchers hope these findings guide consumers, food companies, and governments toward prioritizing sustainable, affordable foods. Masters noted, “There are situations where reducing emissions costs money, because it involves investment in new equipment and power sources. But at the grocery store, frugality is a helpful guide to sustainability.”
Implications for Policy and Future Research
This study provides valuable insights as policymakers and stakeholders work to balance environmental goals with economic realities. By demonstrating that frugality can align with sustainability, the research suggests new pathways for achieving dietary and climate objectives. Future research could further explore the long-term impacts of these dietary shifts on health and the environment.
As the world grapples with climate change and food security challenges, this study offers a hopeful perspective: that cost-effective, environmentally friendly diets are within reach. The findings underscore the importance of informed consumer choices and supportive policies to foster a sustainable future.
Citation: Research reported in this article was conducted as part of the Food Prices for Nutrition project and the Innovative Methods and Metrics for Agriculture and Nutrition Actions project, funded by the Bill & Melinda Gates Foundation and the United Kingdom government. Complete information on authors, methodology, limitations, and conflicts of interest is available in the published paper.
Disclaimer: The content is solely the responsibility of the authors and does not necessarily represent the official views of the funders and their institutions.
