• Blaze Horn

What are the benefits and challenges with a plant based diet?

Updated: Apr 27

The global food system, and particularly agriculture, is one of the largest contributors to climate and environmental change. A plant based diet is often put forward as a solution to some of the issues with our system. Could a plant based diet really be the future of food?

Today’s food supply chain produces approximately 26% of anthropogenic GHG emissions. Agricultural production produce the majority of these emissions (61%, and 81% if deforestation is included), 95% of eutrophication, and 79% of acidification.

It's not great to say the least.

Your diet can, therefore, have a huge affect on the planet and it has become clear that changes must be made to what we eat and where we source it from!

Although the percentages of PBDs are still low compared to omnivores (both plant and meat eaters), their numbers have increased recently.

It is estimated that omnivorous diets currently account for roughly 73%, flexitarian (14%), vegetarianism (5%), veganism (3%), and pescatarian diets (3%).

It's important to remember that data on this topic is limited, and further research is needed to get more accurate numbers, but it shows that there is interest in a move to more PBDs.

Here at Floop, we are firm believers that a veggie, seasonal and local based diet is one of the best ways to reduce your impact on the climate.

And, as we are driven by science, and value applying a critical eye to all scientific research we wanted to share an overview of the benefits and challenges currently associated with PBDs.

It is important to remember that this list is not exhaustive and the science is always being updated.

From our research, there are many clear climatic and environmental benefits of a plant-based diet. These include:

  • Lower GHG emissions. Several studies have examined the diet–climate relationship for PBDs, and there is a general agreement that they result in reductions in GHG emissions per capita.

  • Less water usage. Many studies have also shown that shifts towards more PBDs, could reduce the need for animal water consumption by 14.4% for blue water, and 20.8% for green water.

  • Reduced Land pollution, deforestation and soil degradation. For example, the land needed to raise the feed to produce animal protein is 6–17 times greater than for soy protein.

  • Animal welfare. If we eat more plants, there is less need to kill animals for food.

Of course, concerns have also been raised with the rise of PBDs...

  • Life cycle assessments (LCAs). Many studies have pointed out how different stages in the food’s life cycle: production, processing, transportation, storage, retail, and disposal can cause variance in the level of impact.

For example: in a study conducted on Swedish tomatoes, it was found that the CO2e per kg of domestically produced tomatoes was approximately 4 times higher than the carrots, due to being grown in greenhouses.

This is an interesting point because it demonstrates how 'local' might not always be as good as we think it is...

  • Demand for vegetable/fruit products from abroad. The adoption of PBDs has resulted in the demand for more ‘exotic’ products.

Within Europe, avocado consumption, for example, has increased on average by 179% between 2012/13 and 2017/18. Normally produced in tropical climates, where the need for supplementary irrigation is high, the increasing demand places further pressure on the limited water and land resources, often located in developing, low-income countries.

Broadening your diet is great, but it can come at a cost...

  • Nutritional adequacy. The food industry has adapted to the new trend in PBDs by developing new products that are often aimed to mimicking the qualities of animal-source foods (ASF).

Companies such as Beyond Burger, Quorn, Oatly, and Frankful are a few of the big industry names. Although these new products may be better for the climate and environment, there are limited studies on the health effects of including these products in a PBD.

We all include Ultra-processed foods (UPFs) at some point in our diets, but it's important to remember that just because a product is plant-based it does not necessarily mean it is healthy.

  • Social Norms. Food choices are a combination of: habit, motivation, attitudes, social norms, self-efficacy, and intention.

Young consumers, predominately in developed countries, are leading in the market demand for more plant-based foods. However, meat consumption is ingrained in many modern-day diets, and it is a difficult task to convince certain population groups to change.

We must be understanding of others and their motivations, and be willing to engage in meaningful discussions.

  • Economic accessibility. Accessibility of PBDs also needs to be considered as socio-economic barriers can provide huge challenges to the uptake of sustainable PBDs.

Many high-quality plant-based products, both raw and UPFs, are expensive. Certain communities may also face challenges in obtaining the products, due to them not being available in local stores, even if there is willingness to buy them.

This issue needs to be addressed if we are going to achieve our aim for a more sustainable planet!

We hope that this post hasn't confused you too much! Our aim is to show that there is often a lot more to a subject than first meets the eye, and it is important be open to new research and findings.

If you have any thoughts or questions, let us know in comments below.

Our Sources:

  1. Abeliotis, K., Costarelli, V. and Anagnostopoulos, K. (2016) ‘The Effect of Different Types of Diet on Greenhouse Gas Emissions in Greece.’ International Journal on Food System Dynamics, 7(1) pp. 36-49.

  2. Alcorta, A., Porta, A., Tárrega, A., Alvarez, M.D. and Vaquero, M.P. (2021) ‘Foods for Plant-Based Diets: Challenges and Innovations.’ Foods, 10(2).

  3. Beverland, M.B. (2014) ‘Sustainable Eating: Mainstreaming Plant-Based Diets In Developed Economies.’ Journal of Macromarketing, 34(3) pp. 369-382.

  4. Biasini, B., Rosi, A., Giopp, F., Turgut, R. and Scazzina, F. (2021) ‘Understanding, promoting and predicting sustainable diets: A systematic review.’ Trends in Food Science and Technology, 111 pp. 191–207.

  5. Clark Chai, B., van der Voort, J.R., Grofelnik, K., Eliasdottir, H.G., Klöss, I. and Perez-Cueto, F.J. (2019) ‘Which Diet Has the Least Environmental Impact on Our Planet? A Systematic Review of Vegan, Vegetarian and Omnivorous Diets.’ Sustainability, 11.

  6. Cleveland, D.A. and Gee, Q. (2017) ‘Plant-Based Diets for Mitigating Climate Change.’ In Mariotti, F. (ed.) Vegetarian and Plant-Based Diets in Health and Disease Prevention. Academic Press, pp. 135-156.

  7. Dai, T., Yang, Y., Lee, R., Fleischer, A.S. and Wemhoff, A.P. (2020) ‘Life cycle environmental impacts of food away from home and mitigation strategies—a review.’ Journal of Environmental Management, 265, April.

  8. Faber, I., Castellanos-Feijoó, N.A., Van de Sompel, L., Davydova, A. and Perez-Cueto, F.J.A. (2020) ‘Attitudes and knowledge towards plant-based diets of young adults across four European countries. Exploratory survey.’ Appetite, 145, February.

  9. Food and Agricultural Organisation (FAO). (2012) Sustainable Diets and Biodiversity: Directions and Solutions for Policy, Research and Action. Rome: FAO. [Online] [Accessed on 1st June 2021]

  10. Food and Agricultural Organisation (FAO), International Fund for Agricultural Development (IFAD), United Nations Child’s Emergency Fund (UNICEF), World Food Programme (WFP) and World Health Organisation (WHO). (2020) In Brief to The State of Food Security and Nutrition in the World 2020. Transforming food systems for affordable healthy diets. Rome: FAO. [Online] [Accessed on 1st June 2021]

  11. Hargreaves, S.M., Raposo, A., Saraiva, A. and Zandonadi, R.P. (2021) ‘Vegetarian Diet: An Overview through the Perspective of Quality of Life Domains.’ International Journal of Environmental Research and Public Health 18(8).

  12. Ipsos. (2018) An exploration into diets around the world. Unknown place of publication: Game Changers. [Online] [Accessed on 5th June 2021].

  13. Jalava, M., Kummu, M., Porkka, M., Siebert, S. and Varis, O. (2014) ‘Diet change—a solution to reduce water use?’ Environmental Research Letters, 9, July.

  14. Krizanova, J., Rosenfeld, D.L., Tomiyama, J. and Guardiola, J. (2021) ‘Pro-environmental behavior predicts adherence to plant-based diets.’ Appetite, 163, April.

  15. Kummu, M., Kinnunena, P., Lehikoinena, E., Porkkab, M., Queirozb, C., Röös, E., Troelle, M. and Weilf, C. (2020) ‘Interplay of trade and food system resilience: Gains on supply diversity over time at the cost of trade independency.’ Global Food Security, 24, February.

  16. Lacour, C., Seconda. L., All, B., Hercberg, S., Langevin, B., Pointereau, P., Lairon, D., Baudry, J. and Kesse-Guyot, E. (2018) ‘Environmental Impacts of Plant-Based Diets: How Does Organic Food Consumption Contribute to Environmental Sustainability? Frontiers in Nutrition, 5(8).

  17. Mycek, M.K. (2018) ‘Meatless meals and masculinity: How veg* men explain their plant-based diets.’ Food and Foodways, 26(3) pp. 223-245.

  18. Niva, M., Vainio, A. and Jallinoja, P. (2017) ‘Barriers to Increasing Plant Protein Consumption in Western Populations.’ Vegetarian and Plant-Based Diets in Health and Disease Prevention, In Mariotti, F. (ed.) Vegetarian and Plant-Based Diets in Health and Disease Prevention. Academic Press, pp. 157-171.

  19. Rockström, J., Steffen, W., Noone, K., Persson, Å, Chapin, III, F.S., Lambin, E., Lenton, T.M., Scheffer, M., et al. (2009) ‘Planetary boundaries: exploring the safe operating space for humanity’. Ecology and Society 14(2). [Online]

  20. Rothwell, A., Ridoutt, B., Page, G. and Bellotti, W. (2016) ‘This is proven by the first-ever comprehensive LCA of a whole range of food choices that clearly shows that the highest environmental impact savings lie in the displacement of livestock by plant as a source of protein.’ Journal of Clearer Production, 114, May, pp. 420-430.

  21. Röös, E., Carlsson, G., Ferawati, F., Hefni, M., Stephan, A., Tidåker, P. and Witthöft, C. (2020) ‘Less meat, more legumes: prospects and challenges in the transition toward sustainable diets in Sweden.’ Renewable Agriculture and Food Systems, 35, September, pp. 192–205.

  22. Sabaté, J. and Soret, S. (2014) ‘Sustainability of plant-based diets: back to the future.’ The American Journal of Clinical Nutrition, 100(1) pp. 476-482.

  23. Sadhukhan, J., Dugmore, T.L., Matharu, A., Martinez-Hernandez, E., Aburto, J., Rahman, P.K. and Lynch, J. (2020) ‘Perspectives on “Game Changer” Global Challenges for Sustainable 21st Century: Plant-Based Diet, Unavoidable Food Waste Biorefining, and Circular Economy.’ Sustainability, 12(1976).

  24. Sommaruga, R. and Eldridge, H.M. (2020) Avocado Production: Water Footprint and Socio-economic Implications. London: John Wiley & Sons Ltd, Agricultural Economics Society and European Association of Agricultural Economists. [Online] [Accessed on 5th June 2021].

  25. The Lancet. (2020) ‘The neglected environmental impacts of ultra-processed foods.’ Planetary Health, 4(10) pp. 434-495.

  26. van Vliet, S., Kronberg, S.L. and Provenza F.D. (2020) ‘Plant-Based Meats, Human Health, and Climate Change.’ Frontiers in Sustainable Food Systems 4(128).

  27. Vieux, F., Perignon, M., Gazan, R. and Darmon, N. (2018) ‘Dietary changes needed to improve diet sustainability: are they similar across Europe?’ European Journal of Clinical Nutrition, 72, February, pp. 951–960

  28. Wickramasinghe, K., Breda, J., Berdzuli, N., Rippin, H., Farrand, C. and Halloran, A. (2021) ‘The shift to plant-based diets: are we missing the point?’ Global Food Security, 29, March.