Twenty-six percent of the United States’ total greenhouse gas emissions comes from food production and consumption. So what people choose to eat matters — to personal health and to the global climate.
A new UCLA study published in the journal Nutrients finds that diets centered on plants and unprocessed foods benefit the health of both people and the planet.
The study analyzed six diets: standard American, Mediterranean, vegan, paleo and keto, as well as “climatarian” — a diet that minimizes the consumption of red meats and other foods, such as out-of-season produce, that have large carbon footprints.
Carbon dioxide emissions associated with food come mainly from production, transportation and disposal in landfills, rather than from the food itself. The study’s authors quantified the carbon emissions associated with each of the six diets by using previously published research and a database that tracks foods by their carbon emissions. They analyzed the food consumed in a typical day following each diet, limiting the study to foods that are available in North America, and then standardized the data to 2,000 calories per day.
Their findings:
| Diet | Description | Carbon emissions per day per person | Equivalent carbon emissions in distance driven by car |
|---|
| Standard American | Five main food groups; no reduction of salt, sugar, saturated fats or processed food. | 5.8 to 18 pounds | 6.5 to 20 miles |
|---|
| Mediterranean | Focused on whole grains, fruit and vegetables, fish and olive oil; includes animal products but excludes processsed food. | 4.8 | 5.4 |
|---|
| Vegan | Excludes animal-based products. | 3.6 | 4.0 |
|---|
| Paleo | Excludes processed food and sugars, salts, grains and most dairy. | 6.9 to 13 | 7.7 to 14.6 |
|---|
| Keto | Focused on protein and fat-rich products; limits sugar and grains. | 10.7 to 21.4 | 12.0 to 24.0 |
|---|
| Climatarian | Focused on local, seasonal and fresh food; limits nonsustainable animal products and processed food. | 4.1 to 5.6 | 4.7 to 6.3 |
|---|
While the differences in carbon emissions created by the various diets are relatively small on a per-person per-day basis, they do add up. A climatarian diet with meat would release up to about 4,500 fewer pounds of carbon dioxide per year than a standard American diet — the equivalent of driving a car 5,060 miles.
According to some estimates, more than 80% of the U.S. population consumes the standard American diet. If all of those people converted to a climate-friendly diet, the carbon emissions savings would be roughly equivalent to driving 1.34 trillion fewer miles.
Not only do Mediterranean, vegan and climatarian diets support human health, according to previous research cited by the authors, but they also create smaller carbon footprints because they rely less on red meat and processed foods, said Catherine Carpenter, a UCLA adjunct professor of nutrition and the study’s senior author. Red meat has an especially large carbon footprint because raising animals for meat requires a large amount of land and water, and because livestock flatulence releases methane, a potent greenhouse gas.
And foods that are heavily processed create high carbon emissions because of how they are produced, processed and transported, said Kiera Dixon, the study’s lead author and a master’s student in environmental health sciences at the UCLA Fielding School of Public Health.
“You can decrease your individual carbon footprint quite significantly and still consume meat, but it is highly dependent on the type of meat that you're consuming,” said Malia Michelson, a third-year undergraduate student at UCLA and co-author of the paper.
While people can reduce their climate footprint through the diets they choose, Michelson said, those choices are often limited by financial considerations — climate-friendly food is usually more expensive — and by the availability of certain foods in certain neighborhoods and regions of the country. Michelson said governments could help address the problem by subsidizing healthy food, corporations and other organizations that serve large numbers of constituents could make healthier food more accessible and less expensive, and producers could increase improve labeling to better inform consumers about their food’s climate impact.
The study was conducted in partnership with Airly, a snack food company that was seeking to compare the carbon footprints of various diets. The company played no role in the research or the writing of the paper.
FAQs
Vegan, Mediterranean diets have lower carbon footprints than standard U.S. diet. A UCLA study found that vegan, Mediterranean and climatarian diets create smaller carbon footprints because they rely less on red meat and processed food.
Do vegans have a lower carbon footprint? ›
Going Vegan could reduce an individual's carbon footprint from food by up to 73 per cent, researchers at the University of Oxford found. This is due to the volumes of food which must be fed to livestock before it goes through the energy-intensive process of being killed, processed, transported and stored.
Which diet has the lowest carbon footprint? ›
A vegan diet has the lowest carbon footprint at just 1.5 tons CO2e (Carbon Dioxide Equivalent). You can reduce your foodprint by a quarter just by cutting down on red meats such as beef and lamb. The carbon footprint of a vegetarian diet is about half that of a meat-lover's diet.
What is the carbon footprint of the Mediterranean diet? ›
The Mediterranean diet had a lower environmental impact than Western diets and showed a carbon footprint between 0.9 and 6.88 kg CO2/d per capita, a water footprint between 600 and 5280 m3/d per capita, and an ecological footprint between 2.8 and 53.42 m2/d per capita.
Is a Mediterranean or vegan diet better? ›
Physicians and scientists have long extolled the benefits of both vegan and omnivorous diets, which includes the Mediterranean diet. Is one better than the other? A recent study from Stanford Medicine demonstrated a clear victor when it comes to lowering cholesterol, insulin and weight: the plant-based diet.
What food has the worst carbon footprint? ›
Based on carbon dioxide equivalent (CO2e) measurements, beef comes in first place as the food with the largest carbon footprint, emitting an astounding 99 kilograms of CO2e per kilogram of the final meat product.
What is better for the environment, vegan or vegetarian? ›
Today, the UN says meat and dairy (farmed livestock) accounts for 11.2% of manmade greenhouse gas emissions. But, if we all went vegan, scientists believe the world's food-related emissions might drop by 68% within 15 years, limiting global warming.
Who has the lowest carbon footprint? ›
25 Countries with the Lowest Per-Capita Carbon Emissions
- Djibouti.
- Uganda. ...
- Comoros. ...
- Gambia. ...
- Kiribati. ...
- Malawi. ...
- Tuvalu. Carbon Dioxide Emissions Per Capita (2020): 0.54 tonnes CO2e per capita. ...
- Sierra Leone. Carbon Dioxide Emissions Per Capita (2020): 0.55 tonnes CO2e per capita. ...
Expert-Verified Answer. Nuclear power is the lowest source of carbon emission according to recent studies. We know that fossil fuels contribute to the highest carbon emissions and we believe renewable sources of energy like solar, wind, etc. emit zero to negligible amounts of carbon.
What is the single biggest thing to reduce carbon footprint? ›
Small Changes, Big Impact: 16 Easy Steps To Cut Your Carbon...
- Choose Sustainable Transportation. ...
- Conserve Energy at Home. ...
- Reduce, Reuse, Recycle. ...
- Eat a Plant-Based Diet. ...
- Support Local and Sustainable Products. ...
- Conserve Water. ...
- Educate Yourself and Others. ...
- Offset Your Carbon Footprint.
"Mediterranean diet cuts environmental impact and improves metabolic health, study finds". News-Medical.
Which diet has the lower water footprint in Mediterranean countries? ›
As first major observation, we find that the EAT-Lancet diet, a scientifically optimised diet for both nutrition and certain environmental indicators, requires less water resources than the Mediterranean diet, a culturally accepted diet within the region.
What is the only country with a negative carbon footprint? ›
Bhutan: the only carbon negative country in the world.
Is vegan really the healthiest diet? ›
Vegan diets can be a part of a healthy lifestyle when planned and implemented correctly. Like any eating plan to restrict specific food groups, vegan diets can come up short in essential nutrients such as protein, calcium, iron and vitamin B12.
Is the Mediterranean diet really the healthiest? ›
The Mediterranean diet is a healthy-eating plan. It's focused on plants and includes the traditional flavors and cooking methods of the region. If you're looking for a heart-healthy eating plan, the Mediterranean diet might be right for you. It's less of a diet, meaning a restricted way to eat, and more of a lifestyle.
Why vegan diet is the best? ›
Plant-based diets offer all the necessary protein, fats, carbohydrates, vitamins, and minerals for optimal health, and are often higher in fiber and phytonutrients. However, some vegans may need to add a supplement (specifically vitamin B12) to ensure they receive all the nutrients required.
How much CO2 do you save being vegan? ›
1 vegan day per week (52 days a year) can save nearly 50kgs of CO2 per year. 1 vegan week per month (12 weeks a year) can save nearly 80kgs of CO2 per year.
Does being vegan reduce global warming? ›
Reduce Air Pollution and Greenhouse Gases
Several crops can aid in the reduction of air pollution and greenhouse gas emissions. Vegan diets offer the greatest potential for reducing greenhouse gas emissions. Greenhouse emissions might be decreased by 35% by replacing half of all animal-based meals with vegan diets.
How much lower are vegan's carbon footprints according to PETA? ›
Going vegan can reduce your carbon footprint from food by up to 73%. One-third of the Earth's land surface is used for animal agriculture, and if we all stopped eating meat and dairy, global farmland use could be reduced by 75%. Cows alone produce more than 560 billion litres of methane per day.
Does plant-based meat reduce carbon footprint? ›
When dealing with carbon emissions alone, they are up to 120 times more carbon efficient than meat products. A recent 2021 study found that plant-based patties have a 77% smaller climate change burden than beef patties, with reduced land and water use, eutrophication, and acidification.
