Researchers from Tulane University (USA) for the first time compared popular diets according to the degree of environmental impact. The meta-analysis included data on the nutrition of 16,000 adults. The lowest scores for nutritional quality and the highest for carbon emissions were found in the keto and paleo diets.

According to scientists, a high-fat, low-carb keto diet produces about 3 kg of carbon dioxide for every 1,000 calories eaten. The Paleo diet, based on foods* that our Paleolithic ancestors could have eaten, was in second place in the anti-rating. With a high carbon footprint of 2.6 kg per 1,000 calories, it is also nutritionally unbalanced.
Vegetarian and pescatarian diets also have the least impact on climate. The latter involves the rejection of meat, but it includes fish and seafood. Pescetarianism (from Italian pesce - fish) scored the most points for the quality and balance of nutrition.

The diets were also compared with the "omnivorous" diet: according to scientists, 86% of the study participants adhered to it. This type of food was in the middle of the rating scale for environmental damage and quality. The authors calculated that if at least a third of these people switched to vegetarian diets, carbon emissions would be reduced by the number left by cars that have traveled 500 million km.

Also, nutritional and environmental benefits will improve with the transition to the Mediterranean and DASH diets (restriction of fatty meat to normalize blood pressure).

Previous studies, including a UN-supported 2021 work, have found that 34% of the planet's greenhouse gases come from food production. At the same time, for beef - 8-10 times more than for chicken, and 20 times more than for nuts and legumes. The authors of the new work emphasize that it is possible to improve your diet and reduce your carbon footprint for the health of the planet without completely giving up meat.