Researchers in France recognized that there’s plenty of research showing the environmental benefits of organic food production, and the elevated carbon footprint of animal agriculture, but they wanted to know what it would look like to put the two together.

What they found could interest people who plan their diets with sustainability in mind: Eating organic has the most significant benefits for the climate when a diet is made up mostly—even if not exclusively—of plant foods.

“We wanted to provide a more comprehensive picture of how different diets impact the environment,” said Louise Seconda, author of the study, which was published this month in Frontiers of Nutrition. They looked at people’s diets that weren’t necessarily vegetarian or vegan, and evaluated them according to how many plant-based foods they eat—a “provegetarian” score. Then they assessed three aspects of diet-related environmental impact (using lifecycle assessment at the farm level): greenhouse gas emissions, cumulative energy demand and land occupation.

“Combining consumption and farm production data, we found that across the board, diet-related environmental impacts were reduced with a plant-based diet—particularly greenhouse gas emissions,” Seconda said in a statement. “The consumption of organic food added even more environmental benefits for a plant-based diet. In contrast, consumption of organic food did not add significant benefits to diets with high contribution from animal products.”

She added that plant products on their own only contributed “modest” benefits—so the key seems to be when a diet is heavily plant-based, and not just peppered with vegetables.

There are some caveats to the findings, though: The environmental effects of production systems are not uniform and can be impacted by climate, soil types and farm management, and the researchers didn’t look at other environmental factors like pesticide use or soil quality. “Future studies could also consider these as well as supply chain and distribution impacts of food production,” Seconda said.