Researchers from the Friedman School of Nutrition Science and Policy at Tufts University conducted a comparative analytical study between people’s actual food purchases and the least expensive diets that meet basic health needs, while reducing greenhouse gas emissions.
The results revealed a clear trend across different countries and food cultures, that the least expensive options within most food groups are often the least harmful to the environment.
The study relied on nutritional models specific to each country, based on three main criteria: the cost of food and its local availability, its prevalence in the national diet, and the average carbon emissions per product globally. By comparing several scenarios, it became clear that following a healthy and low-cost diet may be less harmful to the environment compared to common and more expensive diets.
For example, the data showed that switching to relatively cheaper foods such as “milk, eggs, legumes, and small fish like sardines” contributes to reducing emissions compared to relying on red meat. In contrast, the study indicated that “rice,” despite its low price in many countries, leaves a large climate footprint due to methane emissions from its cultivation.
The researchers offer a simple conclusion for consumers and policymakers: “Within each food category, the cheaper option is often the more sustainable option.”
