A major study of nearly 370,000 people in Europe found that eating a wider variety of foods, choosing less processed options, and following healthy eating guidelines can work together to give your body better nutrition while also being better for the environment. Researchers discovered that when people made these three changes at the same time, they got more of the nutrients their bodies need, while also reducing pollution and using less land for food production. The good news is that you don’t need to make huge changes all at once—moderate improvements in all three areas together can make a real difference for both your health and the planet.

The Quick Take

  • What they studied: Whether eating more different types of food, choosing less processed foods, and following healthy eating guidelines can improve nutrition and reduce harm to the environment at the same time.
  • Who participated: Nearly 370,000 adults from across Europe who were part of a long-term health study that tracked what they ate and their health outcomes over many years.
  • Key finding: When people combined three healthy eating habits together—eating more variety, choosing less processed foods, and following healthy guidelines—they got better nutrition while also reducing greenhouse gas pollution by about 1 kilogram of CO2 per day and using less farmland.
  • What it means for you: You don’t need to completely change your diet overnight. Making moderate improvements in eating variety, choosing less processed foods, and following healthy guidelines together can meaningfully improve both your nutrition and help protect the environment. This approach is more realistic and achievable than trying to do one extreme change.

The Research Details

This study used information collected from nearly 370,000 adults in Europe over many years as part of a large health research project called EPIC. Researchers looked at what people ate and measured three important things: how many different types of foods they consumed (food variety), how much ultra-processed food they ate compared to whole foods, and how well their diets matched healthy eating guidelines. They then used computer models to figure out what the ideal diet would look like if someone wanted to get the best nutrition while also reducing environmental damage.

The researchers didn’t randomly assign people to different diets—instead, they studied what people naturally ate and found patterns. They used advanced statistical methods to understand how these three dietary factors worked together and then created computer models to show what an optimal diet might look like for each person based on their current eating habits.

This approach is powerful because it looks at real-world eating patterns from hundreds of thousands of people rather than just testing one specific diet in a small group. The large size and long-term nature of the study makes the findings more reliable and applicable to many different people.

Understanding how different aspects of healthy eating work together is important because most people struggle to change their entire diet at once. This research shows that you don’t have to be perfect in one area—instead, making moderate improvements across multiple areas (eating more variety, choosing less processed foods, and following healthy guidelines) can add up to significant benefits. This makes healthy eating feel more achievable for regular people.

This study is strong because it includes data from hundreds of thousands of people across multiple European countries, making the results more likely to apply to different populations. The researchers carefully measured what people ate using detailed food questionnaires. However, the study relied on people remembering what they ate, which can sometimes be inaccurate. The study also shows associations (connections) rather than proving that making these changes will definitely improve your health, since researchers observed what people naturally ate rather than assigning them to specific diets. The findings were published in a highly respected medical journal, which means other experts reviewed the work before publication.

What the Results Show

When researchers compared people’s actual diets to what an optimal diet would look like, they found several important improvements. People would need to increase their healthy eating score by about 14 points on a 140-point scale, which represents meaningful but achievable changes. Plant variety would increase by about 1-2 additional types of plants per day, and people would replace about 12% of their ultra-processed foods with whole or minimally processed options.

These changes resulted in better nutrition: people would get about 4% more of the nutrients their bodies need. At the same time, the environmental benefits were significant—greenhouse gas emissions from food would drop by about 1 kilogram of CO2 per day (roughly equivalent to driving a car 2-3 miles), and the amount of farmland needed would decrease by about 15 square meters per day (roughly the size of a small bedroom).

The most important finding was that these three changes worked together synergistically, meaning they reinforced each other. When people improved all three areas at the same time, the benefits were greater than if they had focused on just one area. This suggests that a balanced approach to healthy eating is more effective than trying to perfect just one aspect of your diet.

The study found that the benefits were consistent across different groups of people, suggesting these recommendations could work for many different populations. The research also showed that focusing on plant-based foods (rather than animal-based foods) was particularly important for both nutrition and environmental benefits. The findings suggest that moderate changes are more realistic and achievable than extreme dietary overhauls, which is important for long-term success.

Previous research has shown that each of these three factors—food variety, processing levels, and healthy eating guidelines—individually helps with nutrition and environmental sustainability. This study is novel because it’s the first to examine how all three work together. The findings support and expand on earlier research showing that plant-based diets are better for the environment, while also showing that you can achieve good results without being extreme. The study confirms that the EAT-Lancet guidelines (a set of recommendations developed by health and environmental experts) are practical and achievable for real people.

The study relied on people remembering and reporting what they ate, which can be inaccurate. People might forget foods they ate or not remember portion sizes correctly. The study shows associations between diet and outcomes, but doesn’t prove that making these changes will definitely improve your health—it’s possible that other factors not measured in the study could explain the results. The study included mostly European populations, so the findings might not apply equally to people in other parts of the world with different food systems and cultures. The computer models used to create ‘optimal’ diets are based on current nutritional science, which continues to evolve. Finally, the study didn’t track whether people actually followed the recommended diets or what health changes they experienced over time.

The Bottom Line

Based on this research, consider making moderate improvements in three areas: (1) Eat a wider variety of foods, especially different types of plants—aim to include at least 5-10 different plant foods in your weekly diet. (2) Reduce ultra-processed foods like packaged snacks, sugary drinks, and fast food, replacing them with whole foods like fruits, vegetables, whole grains, and legumes. (3) Follow healthy eating guidelines, which generally means eating more plants, less red meat, and appropriate portion sizes. You don’t need to make all these changes at once—start with one area and gradually add the others. The confidence level for these recommendations is moderate to high, as they’re based on a very large study, though the study shows associations rather than definitive proof.

These findings are relevant for anyone interested in improving their health and reducing their environmental impact. They’re particularly useful for people who feel overwhelmed by diet advice and want a more balanced, achievable approach. The recommendations apply to most adults, though people with specific medical conditions or dietary restrictions should consult with a healthcare provider. These findings are less relevant for people in food-insecure situations where food variety and access to whole foods may be limited by availability and cost.

You might notice some benefits relatively quickly—improved energy and digestion could happen within weeks of eating more whole foods and variety. However, meaningful improvements in nutrient levels and health outcomes typically take several months to become apparent. Environmental benefits from your food choices happen immediately in terms of reduced emissions and land use, but the broader environmental impact depends on many people making similar changes. For best results, aim to maintain these dietary changes long-term rather than expecting quick fixes.

Want to Apply This Research?

  • Track the number of different plant-based foods you eat each week (aim for 15-20 different types) and monitor the percentage of your meals that are made from whole or minimally processed foods versus ultra-processed foods. Use a simple weekly checklist to mark off different vegetables, fruits, grains, and legumes you’ve eaten.
  • Start by adding one new plant-based food to your diet each week and replacing one ultra-processed food item with a whole food alternative. For example, swap a packaged snack for a piece of fruit, or replace one fast-food meal with a home-cooked meal using whole ingredients. Use the app to set reminders for meal planning and grocery shopping focused on whole foods.
  • Create a monthly report showing your food variety score, percentage of whole foods versus processed foods, and estimated environmental impact of your diet. Compare month-to-month progress to see how your dietary patterns are improving. Set realistic goals like increasing plant variety by 2-3 foods per month and reducing processed foods by 10% every two months.

This research shows associations between dietary patterns and health and environmental outcomes, but does not prove that making these dietary changes will definitely improve your individual health. Results are based on European populations and may not apply equally to all groups. Before making significant dietary changes, especially if you have existing health conditions, take medications, or have food allergies, consult with your healthcare provider or a registered dietitian. This information is for educational purposes and should not replace professional medical advice. Individual nutritional needs vary based on age, activity level, health status, and other factors.