It is well known that meat has a significant impact on Earth and climate change, as previous research has shown. Now a new study by Oxford scientists has confirmed that plant-based diets have the least impact on the environment.

The study evaluated the environmental impacts of different diets: high and low meat, pescatarian (those who eat fish), vegetarian and vegan using dietary data from more than 55,000 people. The team’s findings, from Oxford University’s Livestock, Environment and People (LEAP) project, showed that the dietary impacts of a plant-based diet were about a third of those of heavy meat eaters, according to a news release on the Oxford Alumni website.

Data on the environmental impact of each diet was examined taking into account its link to greenhouse gas emissions, land use, water use, water pollution risk and biodiversity loss, according to the statement. The assessment also took into account how and where the food is produced. The article is published in Nature Food.

The food system is estimated to be responsible for 70% of the world’s freshwater use and 78% of freshwater pollution, the statement said. Humans have affected most of the earth’s surface, and deforestation continues to play a major role in biodiversity loss.

“Our dietary choices have a huge impact on the planet. Cherry selection data on high-impact plant foods or low-impact meat may obscure the clear relationship between animal-based foods and the environment,” said lead author Peter Scarborough.

The new findings showed that meat-rich diets have the greatest impact on many important environmental indicators, such as climate change and biodiversity loss. Cutting back on meat and dairy can make a substantial difference, she added.

In particular, the study found that, compared to heavy meat eaters, vegans contributed only 27% of water pollution impacts, 46% of water use and 34% of biodiversity. There were at least 30% differences between low and high meat eaters on most indicators.

A 2019 systematic review published in the journal Sustainability found similar results, indicating that a plant-based diet is the best solution for the future. However, he also recognized the difficulty of practicing it, as dietary recommendations might not mesh well with cultural norms and expectations. The researchers suggested linear programming in which a dietary pattern that is both healthy and similar to the environmental impact of a vegan diet can be identified, based on the foods currently consumed by populations in different regions.