Sustainable diets are "dietary patterns that promote all dimensions of individuals' health and wellbeing; have low environmental pressure and impact; are accessible, affordable, safe and equitable; and are culturally acceptable". These diets are nutritious, eco-friendly, economically sustainable, and accessible to people of various socioeconomic backgrounds. Sustainable diets attempt to address nutrient deficiencies (e.g., undernourishment) and excesses (e.g., obesity), while accounting for ecological phenomena such as climate change, loss of biodiversity and land degradation. These diets are comparable to the climatarian diet, with the added domains of economic sustainability and accessibility.
In order to create a sustainable diet, emphasis is placed on reducing the environmental cost incurred by food systems, including everything from production practices and distribution to the mitigation of food waste. At an individual level, most sustainable diets promote reduced consumption of meat and dairy products due to the particularly adverse environmental impact of these industries. Data on the intersection between food and sustainability has been prioritized by a variety of international bodies such as the United Nations Food and Agriculture Organization (FAO) and the World Health Organization (WHO).FAO and WHO. 2019. Sustainable healthy diets – Guiding principles. Rome. http://www.fao.org/3/ca6640en/ca6640en.pdf
History
Sustainable diets were developed to address the dual issues of malnutrition and degradation of environmental resources. The term "sustainable diet" was first coined in the 1986 Dietary Guidelines for Sustainability article by Gussow and Clancy. They describe sustainable diets as "food choices that support life and health within natural system limits into the foreseeable future." The term and its usage was further refined in 2010 by FAO and Bioversity International. The FAO further delineated the constructs of practicing a sustainable diet to be the achievement of optimal growth and development, support for physical, mental, and functional wellbeing, prevention of malnutrition, and promotion of biodiversity and planetary health.
In 2014, the FAO/WHO Second International Conference on Nutrition placed sustainable diets and transformation of food systems as focuses of the UN Decade of Action on Nutrition 2016–2025. In 2019, the FAO and WHO collaborated once again to develop a set of guidelines for sustainable diets and their implementation worldwide.
Components of a sustainable diet The FAO and WHO have outlined the components of a sustainable, healthy diet. The outline divides these components into sections regarding health, environmental, and sociocultural aspects. Each component is also in line with current United Nations Sustainable Development Goals (SDG).
As a whole, sustainable diets emphasize:
Starting early in life with breastfeeding and appropriate complementary feeding A great variety of unprocessed or minimally processed foods and drinks Emphasis on a plant-based diet: whole grains, legumes, nuts, fruits, and vegetables Including moderate amounts of eggs, dairy, poultry, fish, and especially limiting red meat Consuming primarily drinking water Providing adequate energy and nutrients, rather than not reaching or exceeding needs Staying consistent with WHO guidelines to reduce risk of diet-related NCDs Consuming minimal amounts of pathogens, toxins, and other disease agents through food Maintaining greenhouse gas emissions, land use, and chemical pollution targets Preserving biodiversity of crop, livestock, forest-derived foods, genetic resources, and more by avoiding over farming, over hunting, and over fishing Minimizing the use of antibiotics and hormones in food Minimizing the use of plastics and plastic derivatives in food packaging Reducing food loss and waste Respecting local culture, culinary practices, and consumption patterns Being accessible and desirable Avoiding adverse gender-related impacts, especially related to time allocation for buying or preparing food
Health Building a sustainable diet can be analyzed throughout the human lifecycle. According to the United Nations this starts with infant breast feeding. With age, the diet becomes increasingly expanded. For children and adults, it includes a wide variety of minimally processed foods that are balanced across food groups. The most sustainable approach is a primarily plant-based diet, relying heavily on whole grains, legumes, fruits, and vegetables. This is also supplemented by moderate amounts of eggs, dairy, poultry, fish, and minimal red meat. Proportions are meant to be moderate, with all dietary needs satisfied but not heavily exceeded. Finally, a healthy sustainable diet includes safe and clean drinking water.
Environmental impact In order to qualify as a sustainable diet using UN guidelines, a diet must keep greenhouse gas emissions, use of fertilizers, and pollution within established targets. The diet must also reduce the risk of non-communicable diseases and promote general wellbeing. Additionally, foods produced in line with a sustainable diet should minimize antibiotic and plastic use.
Sociocultural impact An ideal sustainable diet takes into account local culture and culinary practices, including emphasis on locally sourced food products and regional food knowledge. The diet must also be accessible and affordable to all without disproportionately burdening one gender over another. This is a crucial part of claiming a sustainable diet. Many consumers do not realize the impacts of certain product production on surrounding communities. Sustainability includes ethical sourcing. A key aspect of sociocultural sustainability is managing and identifying product impacts on cultures, businesses, and employees.
Diets described as sustainable Sustainable diets are typically associated with low-carbon diets, which are structured to combat global warming. The most important example of this is the Plant-based diet. Other approaches focus on broader environmental factors as well as social and economic challenges. For example, one strategy tied to region is the Mediterranean diet, a plant-based diet that is rich in fruits, vegetables, whole-grains, legumes, and fish.
Choosing plant-based proteins promotes health, reduces greenhouse gas emissions, and helps slow the rate of climate change. Examples of plant-based proteins include vegetables, fruits, whole grains, legumes, nuts, and seeds. Research shows these protein sources are low in saturated fats and high in antioxidants, which may help to prevent cancer and cardiovascular diseases. Additionally, the high content of fiber in plant-based proteins may help to regulate blood sugars. Therefore, choosing meat alternatives has the potential to support health for our bodies and the environment.
One common anecdote is that location-oriented sourcing is an important component for lowering the environmental footprint of food purchases. However, a very comprehensive study that gathered data across more than 38k farms recently showed that this is not the case. The carbon and net pollution footprints due to food transportation are almost always negligible compared with other pollutant sources during production. The only exception to this rule are avio-transported food items, which are niche products (e.g., most tropical fruits and nuts do not fly).
A 2020 study found that the climate change mitigation effects of shifting worldwide food production and consumption to plant-based diets, which are mainly composed of foods that require only a small fraction of the land and CO2 emissions required for meat and dairy, could offset CO2 emissions significantly. Data showed this difference is equal to the past 9 to 16 years of fossil fuel emissions in nations that they grouped into 4 types.
Motivations for adopting a sustainable diet
Awareness Awareness about the sustainable benefits of decreasing meat consumption observably increased between 2010 and 2014. A longitudinal study, taking place over the span of these four years, attributed perceived environmental impact to approximately 41% of individuals' explanatory reasoning for consuming less meat.
This study clearly indicated an increase in knowledge about the meat industry's environmental impact. When individuals were asked to comment on whether or not meat consumption is linked to climate change, the number of people who responded positively increased from previous records. Researchers described this increase as part of a "halo" effect. In other words, due to an increase in individuals' health consciousness, economic efficiency, and desire to eat more healthily, there was a resulting increase in their environmental awareness.
Decisions about food consumption have been found to hinge on health, naturalness, price, and sociability. All of these factors are associated with a reduction in meat consumption and increase in willingness to follow a plant based diet, with the exception of sociability. Individuals struggle to alter pre-established eating rituals in social settings out of concern for their public perception. They do not want to seem unsociable or difficult. These particular situations work as a barrier to adopting a more sustainable diet. However, because a positive environmental impact also aligns with an individual's health goals, expenses, and concerns, they are generally more likely to seek it out.
The longitudinal study revealed an increased awareness of the link between meat consumption and environmental impact as well as meat consumption and health outcomes. Emotion-focused coping may provide one explanation for the increase in environmental awareness that eating less meat supports sustainability goals. This concept states that defense mechanisms such as denial and rationalization may be mental strategies used to decrease negative emotions. As individuals begin to partake in more environmentally positive behaviors, regardless of motivation, they could alleviate their need for denial and rationalization in favor of comprehension and understanding that eating healthier is also more environmentally sustainable.
In , the European Commission's Scientific Advice Mechanism concluded in a review of all available scientific evidence that awareness and rational reflection are only a small part of consumers' decision-making process, and therefore that policies to promote sustainable diets should be applied across the whole food system, thus "unburdening the consumer".
Values Motivation is defined as what individuals choose to do, how intensely they choose to do it, and the amount of time the behavior is maintained.Mitchell, T. R., & Daniels, D. (2003). Motivation. In W. C. Borman, D. R. Ilgen, & R. J. Klimoski (Eds.), Handbook of psychology: Industrial and Organizational Psychology. (Vo;. 12, pp. 225–254). Hoboken, NJ: John Wiley & Sons. This definition is not specific to environmental choices and food consumption but can be easily applied. Motivation and personal values are the backbone of environmental behavior and food choices. There are three main value types that are important for further exploration of the current topic: egoistic, altruistic, and biospheric.