Understanding Which Diet Is Typically More Sustainable and the Healthiest

October 13, 2025 •

5 min read

According to the Food and Agriculture Organization of the United Nations, global food systems are responsible for approximately 30% of human-generated greenhouse gas emissions. In this context, it is crucial to ask: which diet is typically more sustainable and the healthiest? This article explores the leading contenders and identifies the core principles that support both human and planetary health for the long term.

Quick Summary

This article analyzes popular dietary patterns, comparing the health and environmental credentials of plant-based and Mediterranean diets. It provides a comparative table, discusses core principles, and concludes that a predominantly plant-forward approach is key for optimal health and sustainability.

Key Points

Plant-Forward is Key: The most sustainable and often healthiest diets are predominantly plant-based, emphasizing whole grains, fruits, vegetables, and legumes, significantly lowering your environmental footprint.
Mediterranean Diet Offers Proven Health: The Mediterranean diet is a gold standard for health, linked to lower risks of heart disease and improved longevity, with a lower environmental impact than typical Western diets.
Flexibility Improves Sustainability: A flexible or 'flexitarian' approach, which reduces but doesn't eliminate animal products, can make the shift toward healthier, more sustainable eating easier and more sustainable for many individuals.
Nutrient Planning is Crucial for Vegans: While offering the lowest environmental impact, strict plant-based diets like veganism require careful planning and potential supplementation to avoid deficiencies in nutrients like B12, iron, and calcium.
Lifestyle Habits Matter: Long-term adherence is boosted by mindful eating, cooking at home, reducing food waste, and choosing local, seasonal produce, regardless of the specific dietary pattern.
Avoid Ultra-Processed Foods: Both health and environmental outcomes are negatively affected by ultra-processed foods, which are high in unhealthy fats, sugar, and additives and require significant resources to produce.

Defining the Criteria for a Sustainable and Healthy Diet

To determine which diet is the best, we must first understand the metrics used to measure health and sustainability. A healthy diet is consistently linked with a lower risk of non-communicable diseases (NCDs), including heart disease, type 2 diabetes, and certain cancers. It provides a balance of macronutrients, sufficient micronutrients, and hydration. Crucially, it emphasizes whole, unprocessed foods while limiting saturated fats, added sugars, and sodium.

Sustainability, on the other hand, considers the environmental footprint of food production and consumption. The key factors include greenhouse gas emissions, water usage, land use, and impact on biodiversity. A truly sustainable diet minimizes resource depletion, reduces waste, and is culturally appropriate, accessible, and affordable for the long term. The most sustainable diets are predominantly plant-based due to the high resource cost of animal agriculture.

The Mediterranean Diet: A Time-Tested Classic

The Mediterranean diet, based on the traditional eating patterns of countries like Greece and Italy, has long been a model for longevity and disease prevention. This diet is rich in plant-based foods, including fruits, vegetables, whole grains, legumes, nuts, and olive oil as the primary fat source. It includes moderate amounts of fish and poultry, with red meat and sweets consumed less often. The health benefits are well-documented, showing a reduced risk of cardiovascular disease, certain cancers, and improved cognitive function.

While highly beneficial for human health, the Mediterranean diet's environmental impact is better than a typical Western diet but not the absolute lowest due to the inclusion of some animal products. However, its focus on local, seasonal produce and minimal processing aligns well with sustainable principles.

Plant-Based Diets: The Greenest Option

The term 'plant-based diet' covers a spectrum of eating patterns, from vegan (no animal products) to flexitarian (primarily plant-based with occasional animal products). All versions emphasize fruits, vegetables, whole grains, legumes, nuts, and seeds. Research shows that these diets are associated with a lower BMI, lower LDL cholesterol, and a reduced risk of heart disease and type 2 diabetes. In terms of environmental sustainability, plant-based diets offer the most significant advantages, with considerably lower carbon emissions, water use, and land requirements than diets high in animal products.

However, stricter plant-based diets, such as veganism, require careful planning to ensure adequate intake of certain nutrients like vitamin B12, iron, calcium, and omega-3 fatty acids. Nutritional awareness and potential supplementation are necessary for optimal health on a strictly plant-based plan.

Comparing Key Characteristics


Criteria	Plant-Based Diet (General)	Mediterranean Diet (Traditional)
Cardiovascular Health	Strong reduction in LDL cholesterol and improved heart health due to low saturated fat and high fiber.	Proven reduction in heart disease risk; includes heart-healthy fats from olive oil and fish.
Environmental Impact	Generally lowest carbon footprint, water usage, and land use compared to other diets.	Lower impact than typical Western diets, but higher than fully plant-based due to moderate animal product consumption.
Weight Management	Often leads to weight loss due to high fiber, low-energy-density foods.	Effective for weight management with moderation and portion control; easier adherence for many.
Cancer Prevention	Associated with lower overall cancer risk, especially digestive and hormonal cancers.	Rich in antioxidants and fiber; lower intake of red and processed meats contributes to protection.
Nutritional Completeness	May require supplementation for key nutrients like B12, iron, and calcium if strictly vegan.	Generally nutritionally complete due to moderate intake of diverse food groups.
Ease of Adoption	Can be challenging due to a significant lifestyle shift for some; growing availability of resources and substitutes helps.	Culturally familiar and more flexible, making adherence potentially easier for a broader population.

Practical Steps Towards a Sustainable and Healthy Diet

Creating a long-term, beneficial diet involves more than just a label. The key is to incorporate habits that promote both personal and planetary health.

Embrace Whole, Minimally Processed Foods

Prioritize produce: Center meals around a variety of fruits, vegetables, legumes, and whole grains. These are nutrient-dense and generally have a lower environmental impact.
Cook at home: Preparing your own meals allows for better control over ingredients and minimizes the use of processed foods high in saturated fat, sugar, and sodium.
Read labels: Avoid ultra-processed foods that contain many artificial additives and ingredients that harm both health and the environment.

Reduce Your Consumption of Animal Products

Choose plant proteins: Incorporate more beans, lentils, tofu, and other plant-based protein sources, which have a significantly lower carbon footprint than meat.
Limit red and processed meat: The World Health Organization (WHO) has classified processed meat as carcinogenic, and red meat is also associated with health risks and a high environmental cost. Aim to reduce or eliminate these from your diet.
Opt for sustainable choices: If including animal products, choose lean meats, poultry, or fish consumed in moderation. For those in Mediterranean regions, locally and sustainably sourced fish can be part of a balanced diet.

Adopt Sustainable Habits

Eat seasonally and locally: Sourcing food from local farmers' markets or growing your own reduces food miles and supports local economies.
Minimize food waste: Planning meals, using leftovers, and composting scraps significantly reduces greenhouse gas emissions from landfills.
Stay active and connect with food: The Mediterranean lifestyle includes communal meals and physical activity. Mindful eating and a connection to your food can improve health outcomes.

The Role of Flexitarianism

For many people, the healthiest and most sustainable choice is a flexible, plant-forward approach that draws inspiration from both Mediterranean and plant-based principles. This flexitarian path allows for dietary variety and cultural considerations while reducing environmental impact and boosting health through a foundation of whole, plant-based foods. This adaptability makes it a highly sustainable and realistic lifestyle change for many. To build a lifetime of healthy eating, it's about shifting your plate's focus—making vegetables, fruits, and whole grains the heroes while treating animal products as supporting cast members or opting for a completely plant-based alternative. More information on adopting a plant-based diet can be found here.

Conclusion

While a strictly vegan diet may offer the lowest environmental footprint, the healthiest and most sustainable long-term approach for most people is a flexible, predominantly plant-based diet like the Mediterranean pattern or a well-planned flexitarian version. These diets consistently deliver strong health benefits by emphasizing nutrient-dense, minimally processed foods. The optimal diet isn't one-size-fits-all, but rather one that is enjoyable enough to be sustained for a lifetime while aligning with a person's values and nutritional needs. For those starting out, a gradual transition to more plant-based meals, prioritizing whole foods, and reducing meat consumption represents a powerful step toward a healthier life and a healthier planet.

Frequently Asked Questions

While often healthier due to high fiber and lower saturated fat, not all plant-based diets are equal. A diet of highly processed vegan junk food is not as healthy as a balanced, whole-food plant-based diet, which requires careful planning for certain nutrients.

Not necessarily. While some specialty organic products can be expensive, many staple sustainable foods like beans, lentils, and seasonal vegetables are more affordable than meat. Reducing food waste and cooking at home can also lead to savings.

You don't have to. Adopting a flexitarian approach, where you prioritize plants while moderately consuming animal products, is a highly effective and sustainable strategy for both personal and planetary health.

Yes, a well-planned plant-based diet can provide adequate protein. Sources like legumes (beans, lentils), tofu, whole grains, nuts, and seeds offer sufficient protein, with plant-based protein intake linked to better long-term health outcomes.

Both diets are excellent for heart health. Studies suggest that a vegan diet may more effectively lower LDL cholesterol, while the Mediterranean diet can be more effective for blood pressure and inflammation. The best choice depends on your specific health goals and preferences.

Start with small, manageable changes. Try incorporating more meatless meals per week, reducing food waste by better meal planning, and choosing more local, seasonal produce.

The EAT-Lancet diet is a flexitarian diet model designed by a commission of scientists to provide a healthy diet from sustainable food systems. It emphasizes whole grains, fruits, vegetables, and legumes while including optional, modest amounts of animal-sourced foods.