With the United Nations' projected population growth globally from 7.8 billion today to nearly 10 billion by 2050, the race is on to find sustainable solutions that feed more with less—more nutritious food with less land, less water, and less human labor. These are complex problems. Wars (figuratively and literally) have been fought over food and continue to be fought today in developed and developing countries. Today, the conflicts are worldwide over how to achieve these goals of “feeding more with less” and the challenges involved in reaching acceptable solutions.
With the projected tripling of population growth globally of nearly 10 billion by 2025, the race is on to find sustainable solutions that feed more with less.
Sustainability is not a new 21st century concept. The term surfaced in the business world in the 1980s as there was a “growing awareness that nations had to find ways to grow their economics without destroying the environment or sacrificing the well-being of future generations.”1 Likewise, there was a growing interest in the nutrition and food communities even earlier to reconnect with food in a more local and sustainable way. Dr Joan Dye Gussow, an early supporter of linking nutrition and the food supply in the 1970s, wrote in the late 1980s about dietary guidelines for sustainability, introducing the term “sustainable diets.” She suggested that sustainable agriculture is one that uses human and natural resources to produce food and fiber in a manner that is conservative, that is, in a manner that is not wasteful of such finite resources as topsoil, water, and fossil energy.2 Simultaneously, questions began to surface about the viability of industrial agricultural practices and the growth of animal protein consumption and its relationship to nutritional quality and the overall sustainability of our population. Despite the 20 plus year span between these early warnings and today, the complexities, challenges, and opportunities remain the same, but the search for research and implementation strategies has significantly intensified.
In the book Triple Bottom Line,1 sustainability is viewed through the lens of measuring the economic, environmental, and social impacts of various practices (Figure 1). During the 2010 International Scientific Symposium held in Rome and hosted by the Food and Agriculture Organization (FAO) of the United Nations, the convergence of sustainability and sustainable diets was formalized. In a presentation by Tim Lang, of the Center for Food Policy, City College, London, stated, “What is a good diet for the 21st century? Nutrition science tried throughout the 20th century to clarify what is a good diet for human health. But today it has little or nothing to say so far about how to marry human and eco-systems health. Here lies a major 21st century food policy challenge.” To quantify the synergy between human health and the planet's health, the definition for sustainable diets created during the symposium was that they were “…those diets with low environmental impacts which contribute to food and nutrition security and to healthy life for present and future generations. Sustainable diets are protective and respectful of biodiversity and ecosystems, culturally acceptable, accessible, economically fair and affordable; nutritionally adequate, safe and healthy; while optimizing natural and human resources.”3 The premise of this definition has been the foundation for food policy discussion and research studies since 2010. Drewnowski4 simplifies it by stating there are 4 domains of a sustainable diet and “to be sustainable, foods and food patterns need to be nutrient-rich, affordable, culturally acceptable, and sparing of natural resources and the environment.”
During the 2018 National Academies of Sciences, Engineering, and Medicine Sustainable Diets Workshop, it was noted that the difference between past and current dialogues about sustainable diets is that most of the conversation centered on the environmental impacts of food systems.5 Yet, priorities regarding economic viability are now coming into play, particularly for those living in low to middle-income countries. Globally, palm oil production in Indonesia and Malaysia is an example of where inequalities drive government to weigh environmental versus economic outcomes, as was noted by Jessica Fanzo of the John Hopkins University. She said, “while it is not great for the environment, nor is it great for human health, palm oil is great for economic growth.”5 The debate on the composition of diets is similar in the case of animal protein. Although the focus on reduction of animal protein as a result of overabundance in the Western diet is viewed as more sustainable, the rapid economic growth and food system transitions being experienced by many low- and middle-income countries are creating an increased, not a decreased, demand for meat.5 Thus, the sustainability conversation between the “haves” and the “have nots” is contentious when it comes to food, and especially who should eat more and who less. When one economy is looking at the issue from a position of overabundance while the other is trying to make ends meet and reach food equality, decisions will play out differently.
Thus, the sustainability conversation between the “haves” and the “have nots” is contentious when it comes to food, and especially who should eat more and who less.
Research studies are equally challenging when the goal is measuring the impact of diet on the environment. In the National Academies of Sciences, Engineering, and Medicine Roundtable, scientists highlighted the challenges of standardizing data collection and measures across research studies because the components of diet patterns (nutrients vs whole foods) are characterized differently in different countries and studies. It was also noted that environmental analyses of studies focused more on greenhouse gas (GHG) emissions without consideration of all the other significant environmental factors, such as eutrophication (the excessive nutrients in water causing dense growth of plant life or death of animal life from oxygen loss) from run-offs of plant and animal agriculture.5 What does this all mean? Even though the reduction of animal protein intake is the only predictive outcome of many modeling studies, there are others, such as how human health outcomes are evaluated in concert with environmental health and economics, that are equally important factors that must also be assessed, especially when comparing studies with each other.
Even though the reduction of animal protein intake is the only predictive outcome of many modeling studies, there are others, such as how human health outcomes are evaluated in concert with environmental health and economics, that are equally important factors that must be assessed, especially when comparing studies with each other.
CONVERGENCE OF SUSTAINABILITY AND HEALTH
The emergence of sustainability within national dietary guidance systems gained momentum globally after the 2010 FAO Symposium on Sustainable Diets, with at least 4 countries (Germany, Brazil, the Netherlands, and Sweden) adding sustainability guidance to their recommendations to the public. Within the United States, the topic of sustainability was raised within the Dietary Guidelines Advisory Committee (DGAC) discussions during the 2005 and 2010 cycles, but no recommendations were made. In 2015, the DGAC included a chapter on sustainability and food safety for the first time, creating much debate. The DGAC Committee recommendations stated “that a diet higher in plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts, and seeds, and lower in calories and animal-based foods is more health promoting and is associated with less environmental impact than is the current U.S. diet.”6 However, after much pressure from Congress and debate about it, the recommendation was not included in the Dietary Guidelines 2015 edition. And in the final rule on producing the Dietary Guidelines for Americans, the secretaries of Agriculture and Health and Human Services concluded that sustainability and evidence on the environmental impacts of dietary patterns should not be included in the 2020 Committee's charge. It remains to be seen if other committees will be appointed to issue such guidance.
In Drewnowski's 2017 review of measures and metrics of sustainable diets, he highlights the challenges of comparing plant- and animal-based foods varying in energy density and nutrient density using the current metrics. He contends that few food groups meet all 4 domains of a sustainable diet (nutrient-rich, affordable, culturally acceptable, and sparing of natural resources and the environment) and tradeoffs need to be made. In the case of nutrient profiling and respective GHG emissions, the need to express outcomes in qualifiable dietary terms (ie, per 100 kcals) is especially highlighted because the current environmental impact factors are calculated as “per 100 g of food,” which is not reflective of human health concerns.4 Because many vegetables have a high water content, comparing plant-based with animal-based foods using weight versus nutrient/caloric density may not represent the actual carbon footprint of a food product. Figure 2 illustrates this point by comparison of mean energy density and mean water content of selected foods.4 In a recent US focused study published in the Proceedings of the National Academy of Science by White and Hall (researchers at Virginia Tech and US Department of Agriculture-Agricultural Research Service), the annual nutritional and GHG impacts of completely eliminating animals from US agriculture were quantified. The outcomes showed that the elimination of animal-based foods from the diet in the US would only result in less than 3% reduction of total US GHG emissions. Yet, the plant-based diets would result in a need for increased food production by 23%, resulting in excess energy supply and a deficiency of several essential nutrients.7
In 2018, Blackstone et al at the University of Vermont compared environmental impact factors of the 3 healthy eating patterns (healthy US-style, healthy Mediterranean-style, and healthy vegetarian) recommended within the 2015–2020 Dietary Guidelines for Americans. This first-time study, based on the recommended dietary patterns, evaluated the policy impact of water depletion, land use, global warming potential, freshwater and marine eutrophication, and particulate matter or respiratory organics. The results show that regardless of the eating pattern, there are environmental consequences. Whereas the healthy US-style and healthy Mediterranean-style patterns had similar environmental impacts, the healthy vegetarian pattern was higher in water depletion but lower in the other impact factors based on the lower protein food content, especially animal-based proteins.8 Based on these results, the authors state that incorporating sustainability into the development of future Dietary Guidelines for Americans has the potential for long-term food security— ensuring that environmental resources are available to meet the nutritional needs of the US population.
Results show that regardless of the eating pattern, there are environmental consequences.
Using 5 identified environmental domains (GHG emission, cropland use, water use, and nitrogen and phosphorus application), Springmann and colleagues analyzed several options for reducing the environmental effects of the food system. Changes in diet with shifts toward global dietary guidelines (with higher plant-based and lower red meat intakes), reductions in food losses and waste, and use of agricultural technologies that affect yield and efficiency were modeled. Between 2010 and 2050, the environmental effects of the food systems were predicted to increase 50% to 90% if the global adoption of agricultural technologies was not increased. Modern agricultural technologies can and do help to close yield gaps and improve resource use efficiencies. The authors conclude that combinations of 3 measures (diet, food loss, and technology use) are needed to mitigate the projected change in environmental impact, rather than a change in 1 single measure.9 Similarly, a large 158-country modeling analysis of the impacts on environmental resources (beyond GHG) and public health outcomes of 3 dietary change strategies was published by Springmann and colleagues in late 2018 in Lancet Planet Health. The outcomes reflected that consumption of predominantly a plant-based diet in high-income countries would decrease mortality rates and reduce the environmental impacts, particularly GHG emissions, whereas freshwater use would be increased with these changes. However, in low-income countries with limited diet diversity, the outcomes were not comparable with those of the high-income countries. In these countries, modification of diet is not a factor. Rather, the reduction of environmental impacts is more aligned with use of technology and better agricultural production management.10
These studies reflect an enormous amount of research published to evaluate the viability of sustainable diets. As illustrated in the examples above, no study is exactly alike, and variance in outcomes is not unusual as land and water use associated with farming varies widely by geography and climate. However, regardless of the type of modeling study that has been conducted, the 1 constant outcome is clear—there is no single solution that will address our food system sustainability conundrum without unintended consequences on one or another factor.
Regardless of the type of modeling study, the 1 constant outcome is clear—there is no single solution that will address our food system sustainability conundrum without unintended consequences on one or another factor.
THE SUSTAINABILITY CONUNDRUM
Numerous academic institutions and food and agriculture organizations are focused on addressing this issue, but differences do exist, reflecting a lack of scientific consensus. EAT, a nonprofit founded by the Stordalen Foundation, Stockholm Resilience Centre, and the Wellcome Trust, was created to build consensus and catalyze a global food system transformation building upon the Paris Agreement climate change goals and the FAO's Sustainable Development Goals. In 2016, The EAT-Lancet Commission for Food, Planet and Health, a group of 20 leading scientists from throughout the world from the fields of nutrition, health, agriculture, food policy, and sustainability, was appointed to address the question “How do we give all humans a healthy diet without depleting the planet's resources?”11 Their charge was to examine all aspects of a sustainable global food system, and to create a report on what actions need to be taken by governments, businesses, and civil society actors to reverse the world's unhealthy practices. The global report “EAT-Lancet Report on Food, Planet and Health” was published by the Lancet in January 2019.11 The focus of the report is on the adoption of a planetary health diet, a flexitarian diet that is largely plant based with inclusion of limited amounts of fish, meat, and dairy foods. The recommendations for a plant-focused diet are based on the conclusions of the authors that a major global food transformation is needed to improve human health and reduce environmental impacts for the long-term capability of feeding 10 billion people by 2050. Greenhouse gas emissions are identified as the largest projected environmental impact of the food system, with animal products—especially meat—as the largest GHG emission contributors in this scenario.12
OPPORTUNITIES—A SHARED JOURNEY
A quote shared by Alyson Noel in her book Fated may summarize our sustainability dilemma appropriately—“There is an old and very wise Native American saying: Every time you point a finger in scorn—there are three remaining fingers pointing right back at you.” When we, as a society look at the rising obesity rates with related chronic diseases, climate change challenges along with the unsolved hunger issues, it is unsettling to realize that what has always been done with the best of intentions is not many times, and what appears to be a simple solution for some other entity to address becomes a complex issue when the focus turns internally.
The challenge continues to be the lack of a clear understanding between consumers and producers about the complexity of defining and measuring sustainability and the multiple factors that contribute. Although sustainability continues to be an increased focus for consumers when making food purchasing decisions, the interpretation of the concept continues to vary. In the 2018 International Food Information Council Foundation Food & Health Survey, most consumers (59%) stated that sustainability was important and identified important aspects of it as reduction of pesticides, an affordable food supply, and conservation of natural habitats. In contrast, production efficiencies and food waste were identified by less than 10%.13 In the Mintel company's Global Food and Drink Trends 2019,14 “evergreen consumption” was highlighted as a major trend. Evergreen consumption is defined as “a circular view of sustainability that spans the entire product lifecycle requiring action from suppliers to consumers.” However, the Nutrition Marketing Institute Sustainability Matters15 overview identifies Millennials as being “aspirational toward sustainability and environmental friendliness, but their behaviors sometimes lag behind their lofty aspirations.” When it comes to dairy and cattle producers, sustainability is viewed through the lens of continuous improvement in the environmental, social, and economic aspects of their operations, hence providing the foundation for consumer desires without the known connection.
Second, adherence to current recommended eating patterns is a significant intervention in addressing the health of the planet and people, but personal commitment will be required. Amidst the modeling studies regarding dietary patterns, it is important to remember that the American food supply and the 2015–2020 Dietary Guidelines for Americans are already plant based and incorporate animal foods based on the scientific evidence of improved health outcomes with their inclusion. Based on the MyPlate icon, 50% of the average US consumer's “plate” should consist of fruits and vegetables and only 15% of protein-rich foods. However, when consumers were asked in the 2018 International Food Information Council Foundation Food & Health Survey, “what percentage of each food category would be on their plate at an average dinner?” they reported less fruits and vegetables than recommended and approximately 40% protein—more than twice the amount of recommended protein.13
The third strategy—reduction of food waste (what is left on the plate, in the refrigerator, and during production)—creates significant environmental issues. It is estimated that 30% to 40% of the food produced in the United States goes uneaten, with approximately 1260 calories per person daily being thrown away while 1 of 6 persons goes hungry.16 The reality is if food waste was a country, it would be the third largest GHG emitter behind China and slightly behind the United States.17 Recognizing that food waste is a food system problem, producers are evaluating practices to reduce the amount of food left behind the field during harvest and retailers are focused on “zero waste” strategies to increase human consumption and reduce landfill disposal. Likewise, consumers need to evaluate purchasing, kitchen preparation, and disposal habits if environmental impacts are to improve.
Fourth and finally, modern production agricultural practices remain at the forefront of solving the problem. Agriculture does have a large footprint on natural resources because food is the core of our existence. However, the center of attention usually focuses on the viability of livestock production and its contribution to the GHG emissions globally rather than in the United States alone. Globally, the contribution of livestock GHG is estimated to be 14%. Because of the US livestock production system's drive for improved health and efficiency of animals, the entire livestock sector contributes only 3.8% of GHG emissions. Comparatively, transportation emissions are 26.4% of the total.18
As an example of how modern agriculture has improved efficiencies, dairy cow numbers between 1950 and 2015 were reduced by 58%, whereas milk production increased by 79%. Likewise, the total number of beef cattle decreased by 20%, whereas the per kilogram of beef production increased by 10% between 1970 and 2015.17 In addition, The Innovation Center for US Dairy was created by dairy farmers through the checkoff in 2008 to address the sustainability of dairy with a unified voice across the value chain. The center promotes best practices across the food value chain, including turning GHG emissions into renewable on-farm energy to change the footprint of animal agriculture. Similarly, in 2015, the US Roundtable for Sustainable Beef was formed as a multistakeholder initiative from across the food value chain to encourage continuous improvement in sustainability. Examples of useful programs include the “pasture to plate” life cycle from water, land, and GHG emission efficiencies to animal welfare and cow-calf productivity and to retail market quality and safety.
SUSTAINABILITY—THE CORE OF OUR EXISTENCE AND CONFLICT
Why the emphasis on the sustainability of our food systems now? The agricultural community contends that sustainability is the core value of their existence, as evident by the conservation of land on which higher-yield crops are grown and meat-producing animals are raised. Others may acknowledge the contributions with the caveat that modern production agriculture has contributed more to the decline of climate change and the overall poor health status of our society than it needed to do. The reality is that food is at the center of our existence and our conflicts. How we manage the conflicts will determine the outcomes of food security for all. The cyclical coexistence of plant- and animal-based food production in nature provides the ecological balance of efficient land and water use while providing the essential combination of nutrients for human existence. If we, as a society, are truly committed to providing sustainable diets that are nutrient-dense, affordable, culturally appropriate, and respectful of the environment, collaboration and consensus building among the total food system are essential.
Committed to providing sustainable diets that are nutrient-dense, affordable, culturally appropriate, and respectful of the environment, collaboration and consensus building among the total food system are essential.
The author thanks Jennifer L. Garrett, PhD, owner of JG Consulting Services, LLC for reviewing this article.
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