We have many environmental challenges. The earth is warming rapidly due largely to man-made green house gases. The population might reach 9 billion people by 2050. Intensive agriculture practices, have threatened soil and water resources. Developing countries are adopting western diets, increasing demand for resource intensive protein resources. As a disclaimer, I write this article with little academic background in agriculture. Like you, I’m trying to sort all of this out as best I can, drawing from credible evidence based resources. That’s what we do in Extension!
I attended the Society of Nutrition Education and Behavior Conference in July and heard several presentations on sustainable diets. Many of presentations challenged my assumptions about what a “sustainable” diet is. Most consumers, don’t really understand what a sustainable diet is either but generally link the term to “organic,” “non-GMO”, or “local,” or “natural.” Most think that these forms of products don’t damage or pollute the environment as much as conventional in regards to chemicals, fertilizers, pesticides, or greenhouse gases. Before we consider these assumptions, we need to consider some established notions of sustainability. Most of these definitions provide that sustainable foods are produced, marketed, consumed, and disposed of in ways that conserve resources (soil and water) for future generations. The Sustainable Research and Education (SARE) group provides pillars of sustainable agriculture:
- Profits over the long term for producers
- Stewardship of our nation’s land, air and water
- Quality of life for farmers, ranchers and their communities
Considering these definitions, what are sustainable diets, foods and practices? The following are some assumptions, and some science challenging the assumptions.
“Everyone should be on vegetarian diet.” Vegetarian diets have many health benefits and devoid of resource-intensive animal protein. The production of animal food contributes substantially more to global warming as well. However, if everyone was vegetarian, grass lands used for ranching, or perennial crops to support livestock, would essentially become unproductive. We might also have to increase production of some other crops as well.
“We should eliminate red meat.” Although a rich source of Heme iron and protein, red meat is less healthy in general, and overconsumption is linked with heart disease and cancer. It is also true that ruminants excrete methane that’s disastrous for global warming, and also need large quantities or resources (water, land, and food) to produce, as compared to poultry, and fish. However, the cattle/ ranching industry is a source of livelihood for countless people. As mentioned above, a large part of our country would become unproductive in terms of agriculture if red meat was to be completely eliminated from our food supply. In addition, it’s important to consider that feeding, and grazing practices differ, and that new techniques such as rotational grazing are being explored.
“Organic is more sustainable.” There is growing scientific opinion that organic practices are more sustainable, however there are mixed findings depending on the crop, region, etc. Big picture though is that organic practices probably aren’t going to solve our planets growing demand for food. Plus, organic foods are expensive and for most products not much more nutritious than conventional foods.
“Everyone should eat local.” There are many benefits of local foods- including supporting local producers and economies. The issue of reducing food miles is controversial, because sometimes crops like wheat, are more efficiently grown in certain areas (Nebraska, South Dakota) than in other regions. Also, the environmental impact of some crops grown thousands of miles away maybe less when considering cost per unit. For example, a train carrying thousands of tomatoes might leave less of a footprint, than a beat-up gas guzzling pick-up hauling a few crates of tomatoes for 20 miles.
“Avoid GMOs.” Good luck! GMO corn and soybeans are ubiquitous in our food supply, either directly, or indirectly. GMOs are controversial, but more with public perception and less so with scientists. Consumers are concerned about food allergies or other health implications which haven’t been proven. GMO crops also often require less pesticide and herbicide.
“If everyone would eat the recommended 5 cups of fruits and vegetables per day, the planet would be healthier.” We should for health reasons. However, could we grow enough to meet up with demand? Plus, vegetables and fruits are water intensive, which could stretch scarce resources out west.
Confused? The point is that there is no “perfect” sustainable diet. In general, eating less protein would help conserve many resources, but eliminating certain protein sources or other products doesn’t really help your health or the planet. Taking all of the previous points into consideration, here are some easy things you could do to support sustainable agriculture. Think variety:
- Balance energy intake with energy needs
- Try to eat only 3 oz of protein per meal. This is the size of a deck of cards, or a quarter of your plate.
- Vary your protein between fish, poultry, beef, and pork.
- Consider a meatless meal once a week.
- Consumer moderate amounts of dairy, fish, nuts and seeds
Author: Dan Remley, MSPH, PhD, Field Specialist, Food, Nutrition, and Wellness, OSU Extension
Reviewer: Susan Zies, M.Ed, Extension Educator, Family and Consumer Sciences
Sources:
Fischer, C.G., and Garnett, T. 2016. Plates, pyramids, planet. Food and Agriculture Organization of the United Nations and The Food Climate Research Network at the University of Oxford.
M.C. Heller & G.A. Keoleian(2014) Greenhouse Gas Emission Estimates of U.S. Dietary Choices and Food Loss. J.Ind.Ecol., 19:3, p. 391-401
P.L.Stanley, J.E.Rowntree, D.K.Beede, M.S.DeLonge, & M.W.Hamm (2018) Impacts of soil carbon sequestration on life cycle greenhouse gas emissions in Midwestern USA beef finishing systems. Agricultural Systems 162 (2018) 249–258.
Tilman, D., & Clark, M. (2014). Global diets link environmental sustainability and human health. Nature, 515(7528), 518-522. doi:10.1038/nature13959
Going Vegan isn’t the Most Viable Option for Humanity. Public Broadcasting System. Accessed at http://www.pbs.org/wgbh/nova/next/earth/going-vegan-isnt-actually-th/
Local Food Is Great, But can it Go to Far? Jonathan Foley. Accessed at https://ensia.com/voices/local-food-not-always-environmentally-sustainable/
Why People Oppose GMOs Even Though Science Says They Are Safe. Scientific American. https://www.scientificamerican.com/article/why-people-oppose-gmos-even-though-science-says-they-are-safe/
What is Sustainable Agriculture? Sustainable Agriculture Research and Education (SARE). Accessed at https://www.sare.org/Learning-Center/SARE-Program-Materials/National-Program-Materials/What-is-Sustainable-Agriculture
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