Plant-Based Substitutions Cut Greenhouse Gas Emissions by Over Half: JAMA
A low-fat vegan diet is associated with a significant reduction in greenhouse gas emissions (GHGE) and cumulative energy demand (CED) compared to the Standard American Diet, according to research by the Physicians Committee for Responsible Medicine published in JAMA Network Open.
The study showed a 51% reduction in GHGE (by 1,313 g CO2-eq/person per day) and a 51% reduction in CED (by 8,194 kJ/person per day), mainly attributable to reduced meat consumption, followed by reduced dairy consumption in GHGE, and reduced egg intake in CED. To put this in perspective, 1,313 grams of CO2e is equivalent to driving a gas-powered vehicle about 4.3 miles. And this reduction in GHGE is happening every day people eat plant-based meals.
“As awareness of its environmental impact grows, swapping plant foods for animal products will be as ubiquitous as reduce, reuse, and recycle,” says Hana Kahleova, MD, PhD, the author of the paper and director of clinical research at the Physicians Committee for Responsible Medicine. A recent survey found that nearly half of Americans would consider eating a plant-based diet to help reduce greenhouse gas emissions.
“We know whole food, plant-based diets are better for our health and the environment,” she adds. “This analysis shows us just how impactful our daily food choices are.”
This research is published just after the EAT-Lancet Commission report issued Oct. 2 said that a global shift toward “healthier diets” that include more fruits, vegetables, and nuts and less red meat is necessary to cut greenhouse gas emissions.
The new research is a secondary analysis of a Physicians Committee study, which found that a low-fat plant-based diet is an effective tool for reducing body weight and increasing insulin sensitivity and postprandial metabolism.
For this secondary analysis of environmental impact of diet, intakes from dietary records were linked to the USDA Food Commodity Intake Database and the database of Food Impacts on the Environment for Linking to Diets.
“Prior research has shown that red meat, in particular, has an outsized impact on energy use compared to grains, legumes, fruits, and vegetables,” Dr. Kahleova says. “Our randomized study shows just how much a low-fat vegan diet is associated with a substantial reduction in greenhouse gas emissions and energy use, significant drivers of climate change.”
Reference:
Kahleova H, Jayaraman A, McKay B, et al. Vegan Diet, Greenhouse Gas Emissions, and Cumulative Energy Demand: A Secondary Analysis of a Randomized Clinical Trial. JAMA Netw Open. 2025;8(11):e2543871. doi:10.1001/jamanetworkopen.2025.43871
