Estonians' current eating habits, especially their preference for meat and dairy, place a strain on the environment and increase health risks, exceeding several of the planet's ecological boundaries. Bashir Bashiri, a newly minted PhD from Tallinn University of Technology (TalTech), studied this complex relationship and used a smart mathematical method to answer a key question: How can people in Estonia eat more healthfully and sustainably without fully abandoning their traditional food culture? His freshly defended dissertation offers practical solutions.

Extent of the problem

According to Bashiri, an analysis of Estonia's nutritional data revealed that the average Estonian consumes around 3,200 kilocalories per day — significantly more than the recommended 2,200. "Overconsumption is especially pronounced when it comes to protein, with intake more than twice the national recommendation," he noted.

Estonia's current diet is structurally unsustainable, relying heavily on animal-based products such as red meat and dairy, which are consumed well above advised levels. These food groups place the greatest strain on the environment, leading the way in greenhouse gas (GHG) emissions, land use and freshwater consumption. Bashiri's dissertation found that the country's current dietary patterns exceed the planet's ecological boundary for land use by 40 percent and for GHG emissions by a staggering 200 percent.

"Animal-based foods, excluding fish, account for about 67 percent of the average diet's land-use footprint, contributing to land cover change, such as deforestation to make way for agriculture. This, in turn, transforms carbon-sequestering areas into emission sources," Bashiri explained. In addition to the environmental burden, such diets are also linked to an increased risk of non-communicable diseases.

"It was precisely the intertwining of these problems that drove us to investigate this topic," Bashiri said. He added that his goal was to offer a realistic and equitable path toward a greener, healthier and more sustainable food system in Estonia.

Novel method

Traditional methods for designing sustainable diets often focus on a single goal, such as reducing carbon emissions, which can lead to impractical recommendations, like completely cutting out red meat, a change that's difficult to implement in real life.

In his work, Bashiri used a method called Multi-Objective Optimization (MOO). "Simply put, it's a mathematical tool that helps find the best balance when you need to meet multiple goals at once," he explained. He likened it to planning a trip: "Imagine you want your trip to be cheap, comfortable and fast. Achieving one often comes at the expense of another. This method helps identify the best possible compromise among competing priorities."

MOO makes it possible to weigh a food's nutritional value, environmental impact (across several indicators), cost and cultural fit all at once, providing balanced, realistic solutions. The approach helps navigate trade-offs between goals like minimizing environmental harm and maintaining cultural acceptability.

The study confirmed that sustainability can't be assessed through a single environmental metric, as different impacts often conflict. "Reducing one type of burden may unintentionally worsen another," Bashiri noted.

He gave the example of land-based fish farming. Although fish has a lower carbon footprint than red meat, its production contributes heavily to eutrophication — the excessive buildup of nutrients in water bodies. In Estonia's comparison diet, fish accounted for 23.3 percent of total eutrophication impact. "This shows that while aquaculture may be climate-friendly, it comes with significant nitrogen and phosphorus emissions," Bashiri explained.

To account for such conflicts and keep the optimization process manageable, Bashiri used a multi-criteria decision-making (MCDM) method called SURE. It allowed him to combine five environmental indicators — land use, greenhouse gas emissions, water use, acidification and eutrophication — into a single composite index before optimization. This simplified the handling of complex trade-offs and enabled two-dimensional optimization.

A more sustainable Estonian diet

Bashiri's findings show that a more sustainable Estonian diet doesn't require eliminating any food group entirely, but rather making balanced reductions and substitutions.

The most important steps are:

• Reducing consumption of dairy and red meat. These two groups are the largest contributors to environmental harm and are currently consumed at high levels in Estonia. According to Bashiri, cutting back on dairy is the most flexible way to optimize the diet, while limiting red meat would benefit nearly all environmental impact areas.
• Increasing the share of lower-impact foods. Models consistently recommend raising the intake of root vegetables (such as potatoes) and grains. These help meet nutritional needs with a smaller environmental footprint.
• Cutting sugar intake. This recommendation appeared in all optimal diet models. Reducing sugary and processed foods benefits both health and the environment.
• Consuming fish in moderation. Due to its significant eutrophication impact, fish should be eaten with caution.

Cultural fit also plays a key role. Changes don't have to be drastic. The optimization process aimed to minimize deviation from the current average diet. "The work emphasizes a gradual and achievable approach — taking small but realistic steps can lead to major, lasting results over time," Bashiri said. Even modest changes, such as reducing land-use impact by 15 percent, are attainable without radically altering eating habits.

Obstacles and solutions

Although an optimal diet has been developed, several barriers stand in the way of its implementation. According to Bashiri, a review of the literature revealed that the main obstacles include low food literacy (knowledge of sustainable choices), the cost, availability and convenience of food, as well as a lack of skills and capacity to manage one's diet.

Overcoming these challenges requires a comprehensive, multi-level approach. In the Estonian context, Bashiri believes the most effective strategy would combine reforming public-sector food services with increasing food literacy.

"Public catering means strengthening sustainability criteria in places like schools, hospitals and other public institutions," Bashiri explained. These institutions can use their purchasing power to make sustainable foods more widely available and set them as the default option, helping to build new habits.

Raising food literacy involves developing knowledge and skills — for example, through plant-based cooking programs in schools. "This boosts people's awareness and confidence, while also dispelling the misconception that sustainable eating is expensive, bland or difficult," Bashiri added.

Additional measures he proposed include better food labeling and financial incentives, such as subsidies for sustainable products or taxes on unhealthy foods.

Estonia's path

Bashir Bashiri's findings align closely with the recently published EAT-Lancet 2.0 report, which calls for a global "planetary health diet." Both emphasize a shift toward more plant-based, nutrient-rich eating, with reduced consumption of meat and dairy products. The main difference lies in the method: Bashiri used multi-objective optimization, which allows for better consideration of local specificities and cultural fit.

"The scenarios we developed can be seen as an Estonia-specific version of the planetary health diet — one tailored to local food preferences and consumption patterns," Bashiri said.

His dissertation carries a clear message for policymakers and the public: change is both possible and necessary. "While shifting an entire society's eating habits won't happen overnight, we can start taking small steps today," he stressed. In his view, even moderate and gradual changes in the right direction can, over time, lead to significant and lasting benefits for both public health and the environment.

Bashiri's research provides a scientifically grounded framework and practical tools for updating Estonia's official dietary guidelines to better incorporate health, environmental and cultural dimensions.

Bashir Bashiri defended his doctoral thesis, "A Multi-Objective Optimization Approach for Design and Implementation of Sustainable Diets," on October 23 at Tallinn University of Technology. His supervisors were emeritus professor Raivo Vilu (TalTech) and researcher Olga Gavrilova (AS TFTAK). The opponents were researcher Mika Jalava (Aalto University) and senior researcher Ellen Trolle (Technical University of Denmark).

--

Follow ERR News on Facebook and X and never miss an update!