A sustainable food system is a type of food system that provides healthy food to people and creates sustainable environmental, economic and social systems that surround food. Sustainable food systems start with the development of sustainable agricultural practices, development of more sustainable food distribution systems, creation of sustainable diets and reduction of food waste throughout the system. Sustainable food systems have been argued to be central to many or all 17 Sustainable Development Goals.
Moving to sustainable food systems is an important component of addressing the causes of climate change. A 2020 review conducted for the European Union found that up to 37% of global greenhouse gas emissions could be attributed to the food system, including crop and livestock production, transportation, changing land use (including deforestation) and food loss and waste. Sustainable food systems are frequently at the center of sustainability focused policy programs, such as proposed Green New Deal programs.
There are many different definitions of a sustainable food system.
From a global perspective, the Food and Agriculture Organization of the United Nations describes a sustainable food system as follows:
A sustainable food system (SFS) is a food system that delivers food security and nutrition for all in such a way that the economic, social and environmental bases to generate food security and nutrition for future generations are not compromised. This means that:
The American Public Health Association (APHA) defines a sustainable food system as:
one that provides healthy food to meet current food needs while maintaining healthy ecosystems that can also provide food for generations to come with minimal negative impact to the environment. A sustainable food system also encourages local production and distribution infrastructures and makes nutritious food available, accessible, and affordable to all. Further, it is humane and just, protecting farmers and other workers, consumers, and communities
The European Union's Scientific Advice Mechanism defines a sustainable food system as a system that:
provides and promotes safe, nutritious and healthy food of low environmental impact for all current and future EU citizens in a manner that itself also protects and restores the natural environment and its ecosystem services, is robust and resilient, economically dynamic, just and fair, and socially acceptable and inclusive. It does so without compromising the availability of nutritious and healthy food for people living outside the EU, nor impairing their natural environment
The study of sustainable food applies systems theory and methods of sustainable design towards food systems. As an interdisciplinary field, the study of sustainable food systems has been growing in the last several decades. University programs focused on sustainable food systems include:
In September 2019, the European Union's Chief Scientific Advisors stated that transitioning to a sustainable food system should be a high priority for the EU:
Although the availability of food is not perceived as an immediate, major concern in Europe, the challenge to ensure a long-term, safe, nutritious, and affordable supply of food, from both land and the oceans, remains. A portfolio of coordinated strategies is called for to address this challenge.
In January 2020, the EU put the transition to a sustainable food system at the core of the European Green Deal. The European Commission's 'Farm to Fork strategy for a sustainable food system', due to be published in spring 2020, is expected to lay out how European countries will reduce greenhouse gas emissions, protect biodiversity, reduce food waste and chemical pesticide use, and contribute to a circular economy.
In April 2020, the EU's Scientific Advice Mechanism delivered to European Commissioners a Scientific Opinion on how to transition to a sustainable food system, informed by an evidence review report undertaken by European academies.
Main article: Food systems
Industrial agriculture causes environmental impacts, as well as health problems associated with obesity in the rich world and hunger in the poor world. This has generated a strong movement towards healthy, sustainable eating as a major component of overall ethical consumerism.
Conventional food systems are largely based on the availability of inexpensive fossil fuels, which is necessary for mechanized agriculture, the manufacture or collection of chemical fertilizers, the processing of food products, and the packaging of foods. Food processing began when the number of consumers started growing rapidly. The demand for cheap and efficient calories climbed, which resulted in nutrition decline. Industrialized agriculture, due to its reliance on economies of scale to reduce production costs, often leads to the compromising of local, regional, or even global ecosystems through fertilizer runoff, nonpoint source pollution, deforestation, suboptimal mechanisms affecting consumer product choice, and greenhouse gas emissions.
Based on the location a person may live at it will determine the amount and type of food resources accessible to them. Therefore, not everyone receives the same quality of food. In addition, conventional channels do not distribute food by emergency assistance or charity. Residents from urban communities do not have to worry about their food system as it always works for them. Urban residents receive a more sustainable food production from healthier and safer sources than low-income communities. Nonetheless, conventional channels are more sustainable than charitable or welfare food resources. Even though the conventional food system provides easier access and lower prices, their food may not be the best for our environment nor health.
Also, the need to reduce production costs in an increasingly global market can cause production of foods to be moved to areas where economic costs (labor, taxes, etc.) are lower or environmental regulations are more lax, which are usually further from consumer markets. For example, the majority of salmon sold in the United States is raised off the coast of Chile, due in large part to less stringent Chilean standards regarding fish feed and regardless of the fact that salmon are not indigenous in Chilean coastal waters. The globalization of food production can result in the loss of traditional food systems in less developed countries, and have negative impacts on the population health, ecosystems, and cultures in those countries.
Furthermore, the conventional food system does not structurally facilitate sustainable patterns of food production and consumption. In decision-making associated with the conventional food system, responsibility is in practice largely thought to rest with consumers and private companies in that they are often anticipated to spend time to – voluntarily and/or without external benefit – seek to educate themselves on which behaviours and specific product-choices are sustainable, in cases where such product-information and education is publicly available, and to subsequently change their respective decision-making related to production and consumption due to prioritized assumed ethical values and sometimes health-benefits, despite substantial drawbacks to such being common. For consumers such drawbacks may include higher prices of organic foods, inappropriate relative monetary price gaps between animal-intensive diets and plant-based ones and inadequate consumer guidance by contemporary valuations. In 2020, an analysis of external climate costs of foods indicates that external greenhouse gas costs are typically highest for animal-based products – conventional and organic to about the same extent within that ecosystem subdomain – followed by conventional dairy products and lowest for organic plant-based foods and concludes contemporary monetary evaluations to be "inadequate" and policy-making that lead to reductions of these costs to be possible, appropriate and urgent.
Main article: Sustainable agriculture
At the global level the environmental impact of agribusiness is being addressed through sustainable agriculture, cellular agriculture and organic farming.
At the local level there are various movements working towards local food production, more productive use of urban wastelands and domestic gardens including permaculture, urban horticulture, local food, slow food, sustainable gardening, and organic gardening.
Main article: Sustainable seafood
Sustainable seafood is seafood from either fished or farmed sources that can maintain or increase production in the future without jeopardizing the ecosystems from which it was acquired. The sustainable seafood movement has gained momentum as more people become aware about both overfishing and environmentally destructive fishing methods.
Despite meat from livestock such as beef and lamb are considered unsustainable, some regenerative agriculture proponents suggest to rear livestock with mixed farming system to restore organic matter in grasslands.   Organizations such as the Canadian Roundtable for Sustainable Beef (CRSB) are looking for solutions to reduce the impact of meat production on the environment.  In October 2021, 17% of beef sold in Canada was certified as sustainable beef by the CRSB.  However, sustainable meat has led to criticism, as environmentalists point out that the meat industry excludes most of its emissions.  
Plant-based meat is proposed for sustainable alternatives to meat consumption. Plant-based meat emits 30%–90% less greenhouse gas than conventional meat (kg-CO2-eq/kg-meat)  and 72%–99% less water than conventional meat.  Public company Beyond Meat and privately held company Impossible Foods are examples of plant-based food production.  However, consulting firm Sustainalytics assured that these companies are not more sustainable than meat-processors competitors such as food processor JBS, and they don't disclose all the CO2 emissions of their supply chain. 
Beyond reducing negative impacts of meat production, facilitating shifts towards more sustainable meat, and facilitating reduced meat consumption (including via plant-based meat substitutes), cultured meat may offer a potentially sustainable way to produce real meat without the associated negative environmental impacts.
Main article: local food
Local and regional food systems, commonly confused with direct marketing but both are distinct terms, come in multiple types and definitions. Local food demands from consumers within these systems include organic practices, greater nutritional value, better quality, and fresher product. Sometimes sold at lower prices, local food supply from farmers can also come at higher costs due to the environmentally sustainable production practices and through direct marketing farmers can even receive benefits for business such as consumer desires through fast product feedback. Local and regional food systems also face challenges such as inadequate institutions or programs, geographic limitations, and seasonal fluctuations which can affect product demand within regions. In addition, Direct marketing also faces challenges of accessibility, coordination, and awareness. Farmers markets, which have increased over the past two decades, are designed for supporting local farmers in selling their fresh products to consumers who are wishing to buy. Food hubs are also similar locations where farmers deliver products and consumers come to pick them up. Consumers who wish to have weekly produce delivered can buy shares through a system called Community-Supported Agriculture (CSA). However, these farmer markets also face challenges with marketing needs such as starting up, advertisement, payments, processing, and regulations.
Debates over local food system efficiency and sustainability have risen as these systems decrease transportation which is a strategy for combating environmental footprints and climate change. A popular argument is the less impactful footprint of food products from local markets on communities and environment. Main factors behind climate change include land use practices and greenhouse emissions as global food systems produce approximately 33% of theses emissions. Compared to transportation in a local food system, a conventional system takes more fuel for energy and emits more pollution such as carbon dioxide. This transportation also includes miles for agricultural products to help with agriculture and depends on factors such as transportation sizes, modes, and fuel types. Some airplane importations have shown to be more efficient than local food systems in some cases. Overall, local food systems support better environmental practices.
However, studies found that food miles are a relatively minor factor of carbon emissions, albeit increased food localization may also enable additional, more significant, environmental benefits such as recycling of energy, water, and nutrients. For specific foods regional differences in harvest seasons may make it more environmentally friendly to import from distant regions than more local production and storage or local production in greenhouses. This may vary depending on the environmental standards in the respective country, the distance of the respective countries and on a case-by-case basis for different foods.
Agricultural productivity is an important component of food security and increasing it sustainably can be an major way to decrease negative environmental impacts such as by decreasing the amount of land needed for farming or reducing environmental degradation like deforestation.
Main article: Sustainable distribution
In food distribution, increasing food supply is a production problem as it takes time for products to get marketed and as they wait to get distributed the food goes to waste. Despite the fact that throughout all food production an estimated 20-30% of food is wasted, there have been efforts to combat this issue such as campaigns conducted to promote limiting food waste. However, due to insufficient facilities and practices as well as huge amounts of food unmarketed or harvested due to prices or quality, food is wasted through each phase of its distribution. Another factor for lack of sustainability within food distribution includes transportation in combination with inadequate methods for food handling throughout the packing process. Additionally, poor or long conditions for food in storage and consumer waste add to this list of factors for inefficiency found in food distribution.
Some modern tendencies in food distribution also create bounds in which problems are created and solutions must be met. One factor includes growth of large-scale producing and selling units in bulk to chain stores which displays merchandising power from large scale market organizations as well as their mergence with manufactures. In response to production, another factor includes large scale distributing and buying units among manufacturers in development of food distribution which also affects producers, distributors, and consumers. Another main factor involves protecting public interest which means better adaptation for product and service which results in rapid development of food distribution. A further factor revolves around price maintenance which creates pressure for lower prices resulting in higher drive for lower cost throughout the whole food distribution process. An additional factor comprises new changes and forms of newly invented technical processes such as developments of freezing food discovered through experiments to help with distribution efficiency. In addition to this, new technical development in distributing machinery to meet the influence of consumer demands and economic factors. Lastly, another factor includes government relation to business those who petition against it in correlation with anti-trust laws due to large scale business organizations and the fear of monopoly contributing to changing public attitude.
Main article: Sustainable diet
The environmental effects of different dietary patterns depend on many factors, including the proportion of animal and plant foods consumed and the method of food production. At the same time, current and future food systems need to be provided with sufficient nutrition for not only the current population, but future population growth in light of a world affected by changing climate in the face of global warming.
Nearly one in four households in the United States have experienced food insecurity in 2020-21. Even before the pandemic hit, some 13.7 million households, or 10.5% of all U.S. households, experienced food insecurity at some point during 2019, according to data from the U.S. Department of Agriculture. That works out to more than 35 million Americans who were either unable to acquire enough food to meet their needs, or uncertain of where their next meal might come from, last year.
In the food industry, especially in agriculture there has been a rise of problems towards the production of some food products. For instance, growing vegetables and fruits has become more expensive. It is difficult to grow some agricultural crops because some have a preferable climate condition for developing. There has also been an incline on food shortages as production has decreased. However, the world still produces enough food for the population but not everyone receives good quality food because it's not accessible to them since it depends on their location and/or income. In addition, the amount of overweight people has increased and there are about 2 billion people that are underfed worldwide. This shows how the global food system lacks quantity and quality according to the food consumption patterns.
A 2020 scientific analysis of external climate costs of foods indicates that external greenhouse gas costs are typically highest for animal-based products – conventional and organic to about the same extent within that ecosystem-subdomain – followed by conventional dairy products and lowest for organic plant-based foods and concludes that contemporary monetary evaluations are "inadequate" and that policy-making that lead to reductions of these costs to be possible, appropriate and urgent.
Main article: Food waste
According to the Food and Agriculture Organization (FAO), food waste is responsible for 8 percent of global human-made greenhouse gas emissions. The FAO concludes that nearly 30 percent of all available agricultural land in the world – 1.4 billion hectares – is used for produced but uneaten food. The global blue water footprint of food waste is 250 km3, that is the amount of water that flows annually through the Volga or 3 times Lake Geneva.
There are several factors that explain how food waste has increased globally in food systems. The main factor is population because as population increases more food production is being made but most food produce goes to waste. In addition, not all countries have the same resources to provide the best quality of food. Therefore, all throughout the world there are different ways that food is being processed. With different priorities different choices are being made to meet their most important needs. Money is another big factor that determines how long the process will take, who is working, and it is treated way differently than low income countries' food systems. However, high income countries food systems still may deal with other issues such as food security. This demonstrates how all food systems have their weaknesses and strengths. Climate change is affecting food waste to increase because the warm temperature causes crops to dry faster and have a higher risk for fires. Food waste can occur throughout any time of production. According to the World Wild Life Organization, since most food produced goes to landfills when it rots it causes methane to be produced. The disposal of the food has a big impact on our environment and health.