Plenty of environmentalists love their meatless diets, and if you’re one of them, you’ve probably asked yourself if meatless is enough... should go vegan too? But are vegan or vegetarian diets ideal for the planet? And what’s the difference?
Firstly, let’s distinguish between vegetarian and vegan diets. Vegetarians eat fruit and vegetables, milk, dairy products and eggs, while excluding any meat, be it beef, poultry or fish. Vegans, instead, exclude any food of animal origin from their daily diet: so, besides meat, they won’t eat dairy products, or eggs.
People choose a vegetarian or vegan diet for many reasons; including ethics, health and the environment…. Eating meat-free is indeed associated with lowering blood pressure and BMI (body mass index). In addition, these diets seem helpful in the treatment of diet-related chronic diseases like heart diseases, diabetes and certain types of cancers (5).
So, we know that reducing meat is good for our body, but what about the effects on our planet… and more specifically, which is most environmentally friendly - veganism or vegetarianism?
The environmental impact of vegetarian and vegan diets
According to a recent meta-analysis on food sustainability (1), both vegetarian and vegan diets had a lower environmental impact than the average omnivorous diet. This is due to the exclusion of meat (1). Meat, especially red meat, produces higher amounts of global warming emissions than any other source of protein.
Average meat consumers in the UK are responsible for 1.5 times more greenhouse gas emissions than vegetarians, and 2 times more emissions than vegans (6). This makes sense… emissions from livestock account for the majority of agricultural emissions (at least 80% of them) (1). 44% of total methane emissions are from livestock alone. Shifting from current diets to vegetarian or vegan diets would lower greenhouse gas emissions from food production and land use, stated the IPCC (Intergovernmental Panel on Climate Change) (7).
However, environmental impact is not about emissions alone: other consequences of meat and dairy production include land and water overuse. Deforestation, land degradation, desertification and biodiversity loss are just a handful of challenges resulting from meat and dairy production. After all, a third of the world’s ice-free land is used for livestock and animal products (9), as well as a third of all freshwater used for agriculture.
Animals have water footprints too! Beside being their favourite drink, water is used to produce animal feeds and then in the processing of meat itself (11). But water consumption at the level required for meat processing and animal feeds can lead to water scarcity and loss of freshwater biodiversity. To add to this, the use of pesticides can increase ecotoxicity, with toxic elements spreading in the environment.
But is all meat equally harmful? Studies have shown that beef has a boldly higher impact than dairy, chicken, pork and eggs - which are comparable in terms of land use, water footprint and emissions. Instead, beef needs more than 20 times more land, and about 10 times more water than the average of the others! (12)
Overall, meat production requires a considerable amount more resources than the staple plant foods such as rice, beans, and potatoes. Let’s take a look at some numbers...
One study calculated that to produce 1 kg of beef, you would need 52 sq m of land, 20,200 litres of water and 17.2 g of pesticides. Instead, the same amount of beans needs a much smaller amount of resources: only 3.8 sq m of land, 2,500 litres of water and 2.2 g of pesticides. The difference is not subtle at all: beans deploy much fewer resources than beef! (3)
Summing it up, considering both emissions and land use, it seems clear that the fewer animal products consumed, the more sustainable the diet (1,2). But it’s not as easy as it sounds. A sustainable diet has plenty to do with individual choices, but also with the awareness of our food’s origins and production methods.
Vegetarian or vegan, which diet has the lowest impact?
Considering emissions and land use, the general rule is that a vegan diet is more sustainable than an omnivorous or even vegetarian diet (1,8). Vegans do not consume any animal products and avoid the negative environmental impacts that these can bring. However, there is plenty more to take into account when considering the full effect of a diet on the environment...
When eating a vegan diet, it always helps to keep informed of the methods of production and the origin of your food. Some fruit and vegetables need plenty of water and soil to grow and may be transported by aircraft over vast distances.
Some vegans make use of industrial products which are often highly processed. Some plant-based meat alternatives generate the same amount of emissions than chicken, while not offering the same nutritional intake.
Different food production and consumption cycles will have an impact on a diet’s carbon footprint. The environmental impact is likely to increase due to food transportation, cooking, storage and waste. For example, cooking can contribute up to 15%-21% greenhouse gas emissions of a food product. Similarly, plant-origin food requiring aircraft transportation or deep-freezing, such as avocados sold in the UK and produced in South America or Spain may create a higher footprint than some dairy or meat national products. But be careful: not all local products are sustainable! Some locally produced vegetables are cultivated in heated greenhouse systems, where they generate more emissions than the same products grown in warmer environments (3).
(Yes we know, it’s a bit of a nightmare!)
For all of the above, the final environmental impact of a vegetarian and vegan diet varies highly among individuals, depending mainly on the mix and proportions of food used. A balanced and healthy vegan diet, with mostly local and seasonal food and the correct protein intake, is likely to have a lower impact than an average vegetarian diet. Ultimately, it’s all about individual awareness, lifestyle and consumer choices!
So, which is better, veganism or vegetarianism? In terms of CO2 emissions, a vegan diet is the most sustainable. A standard vegan diet generates on average 2.89 kg of emissions per day, against the average daily 3.81 kg of a vegetarian diet (figures are considered for standard 2000 kCal diets in the UK).
Top tips for a sustainable diet:
Look for seasonal products. You don’t need to become an expert, this app will tell you when and where your favourite locally grown food is in peak and tastier than ever…
Eat local! Discover your area and the foods which are produced there. Your new favourite farm could be just a few steps away.
The less animal produce, the better! Avoiding dairy, meat, eggs and fish is a really simple way to reduce the environmental impact of your diet.
Stay informed - Reading about food sustainability and the environment will motivate you to go on, there’s so much innovation in the area at the moment.
Good is better than perfect - Start small: even one meat-free meal per week will make the difference.
As we’ve discussed, the road to a balanced and sustainable meat-free diet is long and full of pitfalls, but we shouldn’t be discouraged! There is so much we can do to reduce our food impact, as we learn day by day how to make the best out of our diets... Any questions or comments, feel free to join the discussions via our Instagram channel @thecaptureapp or say hi to the team via email at hello@thecapture.club
References:
Bingli Clark Chai, Johannes Reidar van der Voort, Kristina Grofelnik , Helga Gudny Eliasdottir, Ines Klöss and Federico J. A. Perez-Cueto *. Which Diet Has the Least Environmental Impact on Our Planet? A Systematic Review of Vegan, Vegetarian and Omnivorous Diets. Sustainability 2019, 11, 4110; doi:10.3390/su11154110
Bradley G Ridoutt,1,2 Gilly A Hendrie,3 and Manny Noakes. Dietary Strategies to Reduce Environmental Impact: A Critical Review of the Evidence Base. ã2017 American Society for Nutrition. Adv Nutr 2017;8:933–46; doi: https://doi.org/10.3945/an.117.016691
Ujué Fresán and Joan Sabaté. Vegetarian Diets: Planetary Health and Its Alignment with Human Health. 2019. Adv Nutr 2019;10:S380–S388; doi: https://doi.org/10.1093/advances/nmz019.
Baroni, Berati, Candilera, Tettamanti. Total Environmental Impact of Three Main Dietary Patterns in Relation to the Content of Animal and Plant Food. Foods 2014, 3.
Irana W. Hawkins1,2*, A. Reed Mangels1, Robert Goldman3 and Richard J. Wood. Dietetics Program Directors in the United States Support Teaching Vegetarian and Vegan Nutrition and Half Connect Vegetarian and Vegan Diets to Environmental Impact. Frontiers in Nutrition | www.frontiersin.org 2 August 2019 | Volume 6 | Article 123
Cleveland, D.A.; Gee, Q. Plant-Based Diets for Mitigating Climate Change. In François Mariott, Vegetarian and Plant-Based Diets in Health and Disease Prevention, 1st ed.; Elsevier: Amsterdam, The Netherlands, 2017; pp. 135–156. [CrossRef] [in 1]
Intergovernmental Panel on Climate Change (IPCC). Climate change 2014: synthesis report. Contribution of Working Groups I, II and III to the fifth assessment report of the Intergovernmental Panel on Climate Change [core writing team, RK Pachauri and LA Meyer (eds.)]. [Internet]. IPCC, Geneva, Switzerland, 2014; 151pp.
Sabaté, J.; Soret, S. Sustainability of plant-based diets: Back to the future. Am. J. Clin. Nutr. 2014, 100, 476S–482S. [CrossRef]
Mario Herrero, Petr Havlík, Hugo Valin, An Notenbaert, Mariana C. Rufino, Philip K. Thornton, Michael Blümmel, Franz Weiss, Delia Grace, and Michael Obersteiner. Biomass use, production, feed efficiencies, and greenhouse gas emissions from global livestock systems. PNAS December 24, 2013 110 (52) 20888-20893; Available at https://www.pnas.org/content/110/52/20888
Lukasz Aleksandrowicz ,Rosemary Green, Edward J. M. Joy, Pete Smith, Andy Haines. The Impacts of Dietary Change on Greenhouse Gas Emissions, Land Use, Water Use, and Health: A Systematic Review. Available at: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0165797#pone.0165797.ref004
P.W.Gerbens-LeenesM.M.MekonnenA.Y.Hoekstra. The water footprint of poultry, pork and beef: A comparative study in different countries and production systems. Water Resources and Industry, Volumes 1–2, March–June 2013, Pages 25-36. Available at: https://www.sciencedirect.com/science/article/pii/S2212371713000024#bib31
Gidon Eshel, Alon Shepon, Tamar Makov, and Ron Milo. Land, irrigation water, greenhouse gas, and reactive nitrogen burdens of meat, eggs, and dairy production in the United States. PNAS August 19, 2014 111 (33) 11996-12001; first published July 21, 2014 https://doi.org/10.1073/pnas.1402183111 - Available at: https://www.pnas.org/content/111/33/11996