In light of Earth day, I felt it would be fitting to dedicate my first post to optimising your diet for both human health and planetary health. It’s no secret that climate change is threatening the future and stability of our planet. Despite efforts to address climate change in recent decades, current practices are still not sustainable. Each one of us possesses the power to take small steps that can ultimately make a big impact on our environment. And it all comes down to the food we eat.

 

What is a sustainable diet?

Although there is no universal definition of a sustainable diet, the Food and Agriculture Organization of the United Nations describes sustainable diets as those “with low environmental impacts which contribute to food and nutrition security and to healthy life for present and future generations”¹. The way I see it, having a sustainable diet simply means making food choices with the intent of minimising your impact on the environment.

Note that a sustainable diet doesn’t necessarily have to be plant-based. Although it’s true that plant-based diets have a significantly lower impact on the environment compared to regular omnivore diets², sustainable diets can still include moderate amounts of animal-source foods (eggs, milk, and fish) and small amounts of red meat (beef, lamb, and pork). The diet is typically high in fibre, wholegrains, legumes, and nuts. It is very similar to the Mediterranean Diet, which has proven to be one of the most beneficial diets to adopt in terms of health and longevity³.

 

Why does it matter?

One of the sustainable development goals are to reduce climate change, and the Paris Agreement strives to keep global warming below an increase of 1.5 °C⁴. Reducing greenhouse gases is key to reducing climate change⁵, and one of the biggest ways to do this is by adapting the way we eat. About a third of greenhouse gas emissions can be linked to food⁶, namely the food production system (read more about this here). Eating less red meat is arguably the number one thing you could do to reduce your carbon footprint⁷, not to mention doing so also saves water and reduces deforestation⁸. Switching to a more plant-focused diet and reducing our consumption of red meat and dairy is not only important but necessary to prevent a global warming of 1.5 °C.

The figure below, taken from the FAO 2020 report⁹, shows the amount of greenhouse gas emissions estimated to be produced in 2030 by a typical omnivore diet compared to four alternative healthy diets.

This goes to show how much of a difference you can make simply by making adjustments to your diet to consume less red meat and dairy.

 

ADOPTING ANY OF THE FOUR ALTERNATIVE HEALTHY DIETS CAN DRASTICALLY REDUCE GREENHOUSE GAS EMISSIONS

*Abbreviations: benchmark/omnivore (BMK); flexitarian (FLX); pescatarian (PSC), vegetarian (VEG), vegan (VGN)

Key points:

• 77% of greenhouse gas emissions are associated with animal products, with beef and lamb (41%) and milk and dairy (25%) contributing to the majority of emissions.
• The flexitarian diet, which includes small to moderate amounts of animal products and more plant-based foods, can lower emissions by 40%.
• The vegetarian diet produces less than half the amount of greenhouse gas emissions compared to the omnivore diet.
• The vegan diet brings this down even further (mostly through the elimination of animal milk), producing only roughly 25% of greenhouse gas emissions compared to the omnivore diet.

 

Health benefits

In addition to making a positive impact on the earth, adopting a sustainable way of eating has significant benefits for your health. Multiple systematic reviews and meta-analyses have found beneficial effects of plant-based diets on the body including improved blood sugar regulation and lipid metabolism, decreased inflammatory markers, and better gut health, which may translate into improved weight status and lower risk of cardiovascular disease and type II diabetes^10,11,12,13. Another systematic review and meta-analysis by Farvid et al¹⁴ found that high intake of red meat and processed meat are associated with various types of cancer.

The Mediterranean diet and Okinawa diet are similar in nature to a sustainable diet, characterised by a high intake of fruit and vegetables, moderate consumption of fish, and low intake of meat and dairy products. These diets are rich in antioxidants and promote health, wellbeing, and a longer lifespan¹⁵.

 

How can I adopt a more sustainable way of eating?

1. Reduce your meat intake, particularly red meat

   I know this can be a hard one for a lot of people. Nothing hits quite the same as a juicy steak or a Korean BBQ meal. But if you’re wanting to be intentional about reducing your environmental impact, then consider eating these less often. Maybe try out a chicken burger instead of the beef/pork burger next time. If you often cook with beef/pork mince, try using chicken/turkey or even Quorn mince. You could also try opting for the seafood or vegetarian/vegan option if they have that available at a restaurant the next time you eat out. You might be surprised at how little you’ll be craving meat as you get used to eating it less.
   
   

2. Try meat and dairy alternatives

   In recent years there have been an increasing variety of plant-based alternatives available in supermarkets. One tip I have when it comes to trying out alternatives is to have them without the expectation that they will taste like the “original” product. Even though some brands have nailed the flavour profile and texture of the “original” product (eg plant-based patties replicating beef patties), many of the current products on the market may not taste the same as the animal-derived version. Don’t be disappointed if this is the case. New and better alternatives are constantly being produced, so keep an open mind to new flavours and textures and continue experimenting!
   
   

3. Reduce food waste

   Plan out your meals for the week, create a grocery list, and try not to buy more than what’s on your grocery list. I found that whenever I buy more groceries than I initially planned, I often end up having to throw products away that exceed their use-by date too quickly.
   Re-purpose your food scraps. There are loads of resources and videos online that teach you ways to do this. Some examples include: using vegetable scraps to make a strock or broth, turning broccoli stem into pesto/hummus/soup, or using stale bread to make french toast, croutons, or bread pudding.
   Buy frozen products or freeze your food if you think you won’t be able to use it by the expiry date. You can use frozen fruits to make smoothies and can cook most vegetables from frozen. Frozen fruits and vegetables are very nutritious, and this way, they won’t go bad nearly as quickly.
   
   

4. Eat seasonal and local.

   Buying seasonal and local produce is often cheaper and also reduces the amount of greenhouse gas emissions for the food to get to you (though not as much as reducing meat intake does). It’s also a good way to support your local community!

 

What if I don’t think I can commit to a sustainable diet?

Start small, you don’t have to just decide overnight that you want to completely change the way you eat (assuming you currently eat a lot of meat and dairy). In fact, I would not advise anyone to make extreme drastic changes to their diet in a short amount of time as this can be overwhelming and hard to maintain. It’s easier to stay consistent to a diet by making small changes and implementing one new dietary habit at a time.

For instance, doing Meat-Free Mondays are a good start if you want to try out plant-based alternatives without feeling like you have to commit to a way of eating every day. And keep in mind that there are no rules when it comes to adapting your diet. You don’t even have to put a label on your diet and feel bad if you’re not able to stick to it. As long as the intention is there to make food choices that favour the health of our planet, you are already making a positive impact, even if it may not feel like it.

 

Final thoughts

Developing a more sustainable dietary pattern of eating less meat and dairy and more plant-based foods is key to avoiding environmental (and health) problems. Even though Earth Day is only one day a year, we can strive to be more intentional about our food choices every single day. Whether that’s being willing to try out a plant-based meat alternative or actively reducing your food waste, every conscious decision you make to reduce your environmental impact brings the earth is one step closer to becoming a more sustainable planet.

 

References

1. FAO. Sustainable Diets and Biodiversity [Internet]. Food and Agriculture Organization of the United Nations. Rome: FAO; 2010 Nov. Available from: https://www.fao.org/3/i3004e/i3004e00.htm

2. Chai BC, van der Voort JR, Grofelnik K, Eliasdottir HG, Klöss I, Perez-Cueto FJA. Which Diet Has the Least Environmental Impact on Our Planet? A Systematic Review of Vegan, Vegetarian and Omnivorous Diets. Sustainability [Internet]. 2019 Jul 30;11(15):4110. Available from: https://www.mdpi.com/2071-1050/11/15/4110

3. Guasch‐Ferré M, Willett WC. The Mediterranean diet and health: a comprehensive overview. Journal of Internal Medicine [Internet]. 2021 Aug 23;290(3):549–66. Available from: https://onlinelibrary.wiley.com/doi/full/10.1111/joim.13333

4. United Nations. Climate Action – United Nations Sustainable Development [Internet]. United Nations; [cited 2023 Apr 22]. Available from: https://www.un.org/sustainabledevelopment/climate-action/#ParisAgreement

5. UCAR Center for Science Education. Solving Climate Change [Internet]. scied.ucar.edu. UCAR; [cited 2023 Apr 22]. Available from: https://scied.ucar.edu/learning-zone/climate-solutions/solving-climate

6. United Nations. Food and Climate Change: Healthy diets for a healthier planet [Internet]. United Nations; [cited 2023 Apr 22]. Available from: https://www.un.org/en/climatechange/science/climate-issues/food#:~:text=Food%20needs%20to%20be%20grown

7. Ritchie H, Roser M. Environmental impacts of food production [Internet]. Our World in Data. 2020. Available from: https://ourworldindata.org/environmental-impacts-of-food

8. Poore J, Nemecek T. Reducing food’s environmental impacts through producers and consumers. Science [Internet]. 2018 Jun 1;360(6392):987–92. Available from: https://www.science.org/doi/10.1126/science.aaq0216

9. FAO, IFAD, UNICEF, WFP and WHO. The State of Food Security and Nutrition in the World 2020. Transforming food systems for affordable healthy diets [Internet]. Rome: FAO; 2020. Available from: https://www.fao.org/documents/card/en/c/ca9692en

10. Medawar E, Huhn S, Villringer A, Veronica Witte A. The effects of plant-based diets on the body and the brain: a systematic review. Translational Psychiatry [Internet]. 2019 Sep 12;9(1). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742661/

11. Barnard ND, Levin SM, Yokoyama Y. A Systematic Review and Meta-Analysis of Changes in Body Weight in Clinical Trials of Vegetarian Diets. Journal of the Academy of Nutrition and Dietetics. 2015 Jun;115(6):954–69.

12. Huang RY, Huang CC, Hu FB, Chavarro JE. Vegetarian Diets and Weight Reduction: a Meta-Analysis of Randomized Controlled Trials. Journal of general internal medicine [Internet]. 2016 [cited 2019 Sep 13];31(1):109–16. Available from: https://www.ncbi.nlm.nih.gov/pubmed/26138004

13. Benatar JR, Stewart RAH. Cardiometabolic risk factors in vegans; A meta-analysis of observational studies. Chen O, editor. PLOS ONE [Internet]. 2018 Dec 20 [cited 2019 Mar 19];13(12):e0209086. Available from: https://paperity.org/p/179774221/cardiometabolic-risk-factors-in-vegans-a-meta-analysis-of-observational-studies

14. Farvid MS, Sidahmed E, Spence ND, Mante Angua K, Rosner BA, Barnett JB. Consumption of red meat and processed meat and cancer incidence: a systematic review and meta-analysis of prospective studies. European Journal of Epidemiology. 2021 Aug 29;36(9):937–51.

15. Wichansawakun S, Buttar HS. Chapter 32 – Antioxidant Diets and Functional Foods Promote Healthy Aging and Longevity Through Diverse Mechanisms of Action [Internet]. Singh RB, Watson RR, Takahashi T, editors. ScienceDirect. Academic Press; 2019 [cited 2023 Apr 22]. Available from: https://www.sciencedirect.com/science/article/pii/B9780128131480000323