In 2019, experts from multiple countries and disciplines worked together to create a diet that would be both good for us and good for the planet. They called it the Planetary Health Diet. Despite, the commonsense choices in this food program, the health benefits have been untested until now. Researchers compared it with the famous Mediterranean diet and found both have similar health and sustainability outcomes.
Diet plays a major role in many conditions, including cardiovascular diseases. Healthier diet options, when available, can significantly reduce mortality. The data comes from a large study on dietary choices and cardiovascular risk. From 2008 to 2010, and then in 2012 and 2015, 11,488 Spanish people shared their food intake, physical activity, and drinking patterns. Connecting those with their general health, the research paints a picture of possible outcomes.
The team used that data to assign participants scores based on the two diet options. They found that higher adherence to either diet was associated with lower mortality from all causes. The third of people with the highest adherence to the Planetary Health Diet had a 22 percent lower mortality rate than those in the bottom third. For the Mediterranean diet, the number was 21 percent.
“In 2019, the Planetary Health Diet (PHD) was developed to optimise global dietary quality while keeping the environmental impacts of food production within sustainable planetary boundaries,” study author Dr Mercedes Sotos Prieto of the Autonomous University of Madrid, Spain, said in a statement.
“However, there was a lack of evidence on how the PHD compares with the Mediterranean Diet, a plant-based diet with established health and environmental benefits, that is well rooted in Mediterranean countries. We evaluated the effects of both diets on all-cause mortality and environmental impact in a large representative Spanish population.”
What is the difference between the Planetary Health Diet and the Mediterranean diet?
The difference between these two diets is subtle as in their idealized formulation they are both flexitarian. The Planetary Health Diet‘s main focus is on high consumption of fruit and vegetables, followed by whole grains, legumes, nuts, and unsaturated oils. Starchy vegetables, dairy, poultry, and fish are permitted in moderation, along with very low consumption of red meat, saturated fat, and added sugars.
The Mediterranean diet also has a focus on fruit and vegetables, but grains take center stage. When it comes to meat, white or lean is more common than red, and dairy products, fish, and eggs are allowed in moderation. Olive oil is the main dietary fat. The broad overlap is clear between the two, so it is not surprising that they have very similar outcomes.
While it is good to see demonstrations that the Planetary Health Diet is good for people’s health, it is also good that the Mediterranean diet is not awful for the planet. The PHD had an average daily greenhouse gas emissions of 4.15 kilograms (9.1 pounds) of CO₂ using 5.54 square meters (59.6 square feet) of land. The Mediterranean Diet (that included dairy) was higher on the emissions, 4.36 kilograms (9.6 pounds) of CO₂ per day, but slightly lower on the land use, 5.43 square meters (58.4 square feet) per daily food intake.
“Higher adherence to both diets was similarly associated with lower all-cause mortality and with comparable low environmental impact, highlighting the substantial health and planetary advantages of adopting one of these plant-based diets,” Dr Sotos Prieto concluded.
These results were presented at ESC Preventive Cardiology 2025, a scientific congress of the European Society of Cardiology (ESC).
