An Introduction to Sustainable Diets
Updated: May 11
As a Registered Dietitian who lives on a farm in Southern Ontario, I get asked a lot about diet, sustainability and the environment. Why is eating sustainably so expensive? What is the worst thing to eat for the environment? Do I need to cut out all dairy and meat to be sustainable?
It seems all too often that a new documentary or news story emerges, highlighting yet another food commodity or food system that is not environmentally sustainable. My close friends and family have described feeling confused and conflicted when navigating issues of climate change and diet, feeling as though in order to eat sustainably they must make huge compromises to their current diet. This has inspired me to share my expertise and the latest evidence to help others make informed food choices that checks all the boxes:
· Environmentally conscious
Of course, we all eat differently due to our own unique individualized needs, food preferences, cultures, budgets, etc., so I encourage you to consider these tips and recommendations in the context of your own diet, lifestyle, culture, and personal needs and preferences.
Global climate change is one of the most urgent problems that exists today1. Although the awareness of climate change is growing, the rise of greenhouse gas emissions has continued over the past decade1. Greenhouse gases include carbon dioxide, methane, nitrous oxide, and fluorinated gases2. These gases trap heat in the atmosphere, and as a result, are the primary driver of climate change and the rising global temperatures2. This is no longer a future generation’s problem. As a global community we are already experiencing the negative effects of rising global temperatures and more frequent and inclement weather patterns1. This is only expected to continue. For example, warming and acidifying oceans will decrease fishery yields, and global water scarcity could threaten food security1. Collectively, each of us needs to consider environmental sustainability in the ways we live, work, eat, play, and vote. The health of our planet concerns all of us and food production and food systems are a powerful vehicle for change.
“Food is the single strongest lever to optimize human health and environmental sustainability on Earth”. – EAT Lancet Report
The EAT Lancet report was created by 37 of the world’s leading scientists from various fields including human health, agriculture, political science, and environmental sustainability3.
Greenhouse gas emissions produced during food production can be broken down into livestock and fisheries, crop production, land use, and supply chain4. This means that when considering diet sustainability, we need to acknowledge the energy, resources and by-products (i.e., carbon dioxide & methane) of growing food, as well as retail packaging, food transportation, and food processing4. The largest contributor of greenhouse gas emissions comes from growing food, although not all foods are equal in this regard4. The research shows that animal products continue to create more emissions compared to plant-based foods1. In addition, emissions are only one part of the story. Sustainability is also about preserving biodiversity and water, land, and air quality1.
The Food and Agriculture Organization of the United Nations defines a sustainable diet as “one with low environmental impacts which contributes to food and nutrition security and to healthy life for present and future generations”5. This definition shows that a sustainable diet incudes not only environmental impact, but also nutrition, access, affordability, and culture. The EAT Lancet Report developed targets for a ‘win-win’ scenario, where both environmental health and human health are achieved3. What is now referred to at the Planetary Health Plate3.
The Planetary Health Plate emphasizes a diet rich in plant-based foods, with:
1/2 plate vegetables and fruits
1/2 plate whole grains + plant protein sources + unsaturated plant oils
Optional: modest amounts of animal sources of protein.
To achieve a more sustainable diet, the research overwhelming suggests a diet that focuses on plant-based foods, limiting animal products, and reducing food waste. The Planetary Health Plate doesn’t mean compromising on all our favourite foods, but rather tweaking the amount and frequency of foods that have a higher environmental impact. Completely eliminating all animal foods may not support everyone’s physical, mental, cultural, and economic needs, and is it not the only way to eat sustainably.
The Planetary Health Plate it quite similar to Canada’s Food Guide, and that’s because a diet rich in vegetables, fruits, whole grains, nuts & seeds, and beans & lentils, with small amounts of meat, dairy, and eggs has also been proven to reduce the risk of chronic diseases such as cancer, heart disease and stroke, and diabetes3. Hence the win-win scenario!
How can you begin to eat more sustainably?
Eating more plant-based meals daily, or weekly, is a good place to start.
Think about areas where you can add more plant-based foods in rather than only considering what to cut out. What plant-based foods do you already enjoy? Are there others you have always wanted to try? Could you have these foods more often? Adopting a more sustainable diet is about what you do most of the time, and doesn’t mean compromising on flavour, enjoyment, or satisfaction. If you are new to plant-based eating, at your next taco night try using both ground beef AND lentils to make your taco “meat”.
Other Ideas Include:
1) Eating fruits and vegetables that are local and in season. Ever noticed how Ontario strawberries are so much more flavourful and satisfying? Well, that’s because the strawberries you may buy over the winter travel so far to get to us. For my Canadian and Ontario folks, we are about to embark on another plentiful growing season so consider planning meals around these foods. Check out Foodland Ontario for more information.
2) Consider growing your own food! Growing your own vegetables, fruits, and herbs can help build your appreciation for food and food growers and is a great learning opportunity for the whole family.
Freshly picked chives!
3) Here are some other simple and easy plant-based recipes:
This is a HUGE topic, let us know in the comments if you are interested in learning more about diet and sustainability in future blogs and recipes!
1. Rose, D., Heller, M. C., & Roberto, C. A. (2019). Position of the Society for Nutrition Education and Behavior: the importance of including environmental sustainability in dietary guidance. Journal of nutrition education and behavior, 51(1), 3-15.
2. Ritchie, H., & Roser, M. (2020). CO₂ and Greenhouse Gas Emissions. Our World in Data. Retrieved from: https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions
3. Willett, W., Rockström, J., Loken, B., Springmann, M., Lang, T., Vermeulen, S., & Murray, C. J. (2019). Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems. The Lancet, 393(10170), 447-492.
4. Ritchie, H. (2019). Food Production Is Responsible for One-Quarter of the World’s Greenhouse Gas Emissions. Our World in Data. Retrieved from: https://ourworldindata.org/food-ghg-emissions
5. FAO. (2010). Sustainable Diets and Biodiversity. Retrieved from: http://www.fao.org/nutrition/education/food-dietary-guidelines/background/sustainable-dietary-guidelines/en/