Eating for Planetary and Human Health

Sustainability and Diet 
     ​A sustainable diet recognizes the interdependence of the health of humans, plants, animals, ecosystems, and the planet. Currently, the food system produces one-third of all greenhouse gas emissions, uses a large amount of water and land, and threatens biodiversity. In this blog, we will explore a few aspects of a sustainable diet and some individual choices you can make to decrease greenhouse gas emissions, land usage, and water usage.

What is a Sustainable Diet?
     According to the Food and Agriculture Organization, sustainable diets are those with a low environmental impact, are culturally acceptable, affordable, use natural resources responsibly, and consider future generations' wellbeing. Criteria under consideration for sustainable diets include:  

• greenhouse gas emissions
• water use
• land use
• maintaining biodiversity
• animal and plant population health
• the impact on surrounding ecosystems
• affordability for the consumer and fair to the producer 
• having culturally relevant foods accessible 

     ​​More sustainable dietary patterns include increased intake of vegetables, fruit, whole grains, beans/lentils, and other plant-based foods. Plant-forward diets like the DASH, Mediterranean, and vegan/vegetarian diets also have lower environmental impacts than the Standard American Diet.

Environmental Impact of Specific Foods    
     In contrast to what a sustainable diet is, the following lists some of the foods with high environmental impacts: 

• Beef, lamb, and pork (then followed by eggs, milk, and rice) have the highest amount of greenhouse gas emissions 
• Animal products (like meat, poultry, eggs, milk, etc.), sugar, legumes, and rice have the highest freshwater usage 
• Animal-based foods, legumes, vegetable oils, oil crops, and nuts/seeds have the highest land usage ​​

     ​Sustainable and plant-forward diets don’t need to exclude meat and animal products; instead, emphasize and include more plant-based foods. 

The Connection between Human Health and Planetary Health
     ​Choosing diets rich in whole and plant-based foods benefits the planet and human health. A plant-based diet rich in whole foods includes nutrients like fiber, phytochemicals, minerals, and vitamins. It is also anti-inflammatory. According to the American Heart Association, consuming less meat and more whole plant-based foods is associated with lower rates of heart disease, stroke, obesity, high blood pressure, high cholesterol, type II diabetes, and many cancers. The Mediterranean diet is also associated with decreased cancer, cardiovascular disease, and cognitive decline rates. It’s an added benefit that eating healthfully often coincides with caring for the environment.

Tips for Implementing a More Sustainable Diet 

Try the Healthy Plate Method 
     When designing meals, using the Healthy Plate method can help create a balanced plant-forward meal. The Healthy Plate has ½ of your plate as non-starchy vegetables and fruit, ¼ of your plate protein, and ¼ of your plate carbohydrates (choose whole grains and complex carbohydrates when possible). This method will help you fill more of your plate with vegetables and plant-based foods. Check out the Harvard website to get more information and a picture of the Healthy Plate Method that can help you follow this dietary pattern:
​
Mixing up Protein Choices 
     When choosing proteins, consider choosing plant-based proteins (like beans, lentils, tofu, seitan, nuts, seeds, soy, etc.), fish, or poultry a few times a week to increase the sustainability of your diet. While legumes have a relatively high land and water usage, their land and water usage and greenhouse gas emissions are still lower than those of red meat. Poultry and fish also have a lower environmental impact than red meat. 

Local and Seasonal Foods
     ​Another aspect of sustainable diets is choosing local or seasonal foods. This can reduce the carbon footprint from transportation and storage, connect people to their local food systems and farmers, and enhance the local economy. Due to the globalization of the food system, food often travels hundreds of miles before it reaches our plates. Local, seasonal produce also has higher amounts of certain antioxidants and vitamins that can break down during transportation and storage.
    Here in Washington, summer is arriving. Some foods that are in season include strawberries, chives, cilantro, fennel, arugula, baby bok choy, chards, collard greens, dandelion greens, lettuce, spinach, snap/snow peas, pea vines, radishes, rhubarb, and many others. Some ways to be a part of the local harvest include attending local farmers markets, considering a CSA from a local farm, or buying these foods in grocery stores. Check out the seasonality charts below for more information on local, seasonal produce: 

• SeasonalityChart-FruitsHerbs (wa.gov)
• SeasonalityChart-VegetablesLegumes (wa.gov)

Seasonal Recipe: Strawberry Spinach Salad with Poppy Seed Dressing

Try this salad with local and spring/summer season ingredients from Washington, like fresh strawberries and spinach.

 Strawberry Spinach Salad: 

• 3/4 cup raw pecans
• 1/2 small red onion (very thinly sliced) 
• 10 ounces spinach 
• 1-quart strawberries (hulled and quartered)
• 3/4 cup crumbled feta cheese​

Poppy Seed Dressing: 

• 1/4 cup balsamic vinegar
• 3 tablespoons extra-virgin olive oil
• 1 1/2 tablespoons poppy seeds
• 1 1/2 tablespoons honey
• 1/2 teaspoon Dijon mustard
• 1/2 teaspoon kosher salt
• 1/8 teaspoon black pepper

Instructions: 

1. Preheat the oven to 350 degrees F and place pecans on an ungreased baking sheet. Bake for 8 to 10 minutes. Remove pecans from oven, place on a cutting board, and roughly chop pecans. 
2. In a small mixing bowl, combine vinegar, oil, poppy seeds, honey, mustard, salt, and pepper and whisk together until well combined. 
3. Place the spinach in a large bowl. Add the strawberries, red onion, feta, and pecans. Toss lightly. Add dressing to personal preference and serve. 

Rebecca Griest, Dietetic Intern, Seattle Pacific University

Sources: 

1. Swain M, Blomqvist L, McNamara J, Ripple WJ. Reducing the environmental impact of global diets. Science of The Total Environment. 2018;610-611:1207-1209. doi:https://doi.org/10.1016/j.scitotenv.2017.08.125
   
2. Sustainable Diets and Biodiversity Directions and Solutions for Policy, Research, and Action. https://www.fao.org/3/i3004e/i3004e.pdf
   
3. Macdiarmid JI. Seasonality and dietary requirements: will eating seasonal food contribute to health and environmental sustainability? Proceedings of the Nutrition Society. 2013;73(03):368-375. doi:https://doi.org/10.1017/s0029665113003753
   
4. Kowalsky TO, Morilla Romero de la Osa R, Cerrillo I. Sustainable Diets as Tools to Harmonize the Health of Individuals, Communities and the Planet: A Systematic Review. Nutrients. 2022;14(5):928. doi:https://doi.org/10.3390/nu14050928
   
5. Dernini S, Berry E, Serra-Majem L, et al. Med Diet 4.0: the Mediterranean diet with four sustainable benefits. Public Health Nutrition. 2016;20(7):1322-1330. doi:https://doi.org/10.1017/s1368980016003177
   
6. Plates, Pyramids, and Planets. Food and Agriculture Organization of the United Nations. FAO. https://www.fao.org/documents/card/en/c/d8dfeaf1-f859-4191-954f-e8e1388cd0b7/
   
7. ‌Washington Grown Fruits, Legume and Herbs Seasonality Chart. Accessed April 10, 2024.https://agr.wa.gov/getmedia/497c614b-5c54-4277-89cf-4d6d1dd79c52/seasonalitychartfruitlegumeherbsfinal.pdf
   
8. Spinach Strawberry Salad With Poppy Seed Dressing. Well Plated by Erin. Published March 12, 2020. https://www.wellplated.com/spinach-strawberry-salad
   
9. American Heart Association. How Does Plant-Forward (Plant-Based) Eating Benefit Your Health? www.heart.org. Published 2019. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/nutrition-basics/how-does-plant-forward-eating-benefit-your-health
   

Healthy Eating Plate. The Nutrition Source. Published September 18, 2012. https://nutritionsource.hsph.harvard.edu/healthy-eating-plate/