Balanced growth of nutritional substances and their distribution
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, including via shifting consumption to sustainable diets, is an important component of addressing the causes of climate change and adapting to it. 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. Reduction of meat production, which accounts for ~60% of greenhouse gas emissions and ~75% of agriculturally used land, is one major component of this change. ;ref name="10.1146/annurev-resource-111820-032340a" ; ;/ref ;
The global food system is facing major interconnected challenges, including mitigating food insecurity, effects from climate change, biodiversity loss, malnutrition, inequity, soil degradation, pest outbreaks, water and energy scarcity, economic and political crises, natural resource depletion, and preventable ill-health.
The concept of sustainable food systems is frequently at the center of sustainability-focused policy programs, such as proposed Green New Deal programs.
Definition.
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:
 ;templatestyles src="Template:Blockquote/styles.css" / ;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:
 ;templatestyles src="Template:Blockquote/styles.css" / ;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:
 ;templatestyles src="Template:Blockquote/styles.css" / ;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
Problems with conventional food systems.
Industrial agriculture causes environmental impacts, as well as health problems associated with both obesity and hunger. This has generated a strong interest in healthy, sustainable eating as a major component of the overall movement toward sustainability and climate change mitigation.
Conventional food systems are largely based on the availability of inexpensive fossil fuels, which is necessary for mechanized agriculture, the manufacturing 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.
Food and power.
In the contemporary world, transnational corporations execute high levels of control over the food system. In this system, both farmers and consumers are disadvantaged and have little control; power is concentrated in the center of the supply chain, where corporations control how food moves from producers to consumers.
Disempowerment of consumers.
People living in different areas face substantial inequality in their access to healthy food. Areas where affordable, healthy food, particularly fresh fruits and vegetables, is difficult to access are sometimes called food deserts. This term has been particularly applied in the USA. In addition, conventional channels do not distribute food by emergency assistance or charity. Urban residents receive 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 the environment nor consumer health.
Both obesity and undernutrition are associated with poverty and marginalization. This has been referred to as the "double burden of malnutrition." In low-income areas, there may be abundant access to fast-food or small convenience stores and "corner" stores, but no supermarkets that sell a variety of healthy foods.
Disempowerment of producers.
Small farms tend to be more sustainable than large farming operations, because of differences in their management and methods. Industrial agriculture replaces human labor using increased usage of fossil fuels, fertilizers, pesticides, and machinery and is heavily reliant on monoculture. However, if current trends continue, the number of operating farms in existence is expected to halve by 2100, as smallholders' farms are consolidated into larger operations. The percentage of people who work as farmers worldwide dropped from 44% to 26% between 1991 and 2020.
Small farmers worldwide are often trapped in poverty and have little agency in the global food system. Smallholder farms produce a greater diversity of crops as well as harboring more non-crop biodiversity, but in wealthy, industrialized countries, small farms have declined severely. For example, in the USA, 4% of the total number of farms operate 26% of all agricultural land.
Complications from globalization.
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.
Globalization of sustainable food systems has coincided the proliferation of private standards in the agri-food sector where big food retailers have formed multi-stakeholder initiatives (MSIs) with governance over standard setting organizations (SSOs) who maintain the standards. One such MSI is the Consumer Goods Forum(CGF). With CGF members openly using lobbying dollars to influence trade agreements for food systems which leads to creating barriers to competition. Concerns around corporate governance within food systems as a substitute for regulation were raised by the Institute for Multi-Stakeholder Initiative Integrity. The proliferation of private standards resulted in standard harmonization from organizations that include the Global Food Safety Initiative and ISEAL Alliance. The unintended consequence of standard harmonization was a perverse incentive because companies owning private standards generate revenue from fees that other companies have to pay to implement the standards. This has led to more and more private standards entering the marketplace who are enticed to make money.
Systemic structures.
Moreover, the existing conventional food system lacks the inherent framework necessary to foster sustainable models of food production and consumption. Within the decision-making processes associated with this system, the burden of responsibility primarily falls on consumers and private enterprises. This expectation places the onus on individuals to voluntarily and often without external incentives, expend effort to educate themselves about sustainable behaviours and specific product choices. This educational endeavour is reliant on the availability of public information. Subsequently, consumers are urged to alter their decision-making patterns concerning production and consumption, driven by prioritised ethical values and sometimes health benefits, even when significant drawbacks are prevalent. These drawbacks faced by consumers include elevated costs of organic foods, imbalanced monetary price differentials between animal-intensive diets and plant-based alternatives, and an absence of comprehensive consumer guidance aligned with contemporary valuations. In 2020, an analysis of external climate costs of foods indicated 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. It finds contemporary monetary evaluations to be "inadequate" and policy-making that lead to reductions of these costs to be possible, appropriate and urgent.
Sourcing sustainable food.
At the global level the environmental impact of agribusiness is being addressed through sustainable agriculture, cellular agriculture and organic farming.
Various alternatives to meat and novel classes of foods can substantially increase sustainability. There are large potential benefits of marine algae-based aquaculture for the development of a future healthy and sustainable food system. ;ref name="10.5670/oceanog.2022.213" ; ;/ref ; Fungiculture, another sector of a growing bioeconomy besides algaculture, may also become a larger component of a sustainable food system. Consumption shares of various other ingredients for meat analogues such as protein from pulses may also rise substantially in a sustainable food system. The integration of single-cell protein, which can be produced from captured CO2. Optimized dietary scenarios would also see changes in various other types of foods such as nuts, as well as pulses such as beans, which have favorable environmental and health profiles. 
Complementary approaches under development include vertical farming of various types of foods and various agricultural technologies, often using digital agriculture.
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. The goal of sustainable seafood practices is to ensure that fish populations are able to continue to thrive, that marine habitats are protected, and that fishing and aquaculture practices do not have negative impacts on local communities or economies.
There are several factors that go into determining whether a seafood product is sustainable or not. These include the method of fishing or farming, the health of the fish population, the impact on the surrounding environment, and the social and economic implications of the seafood production. Some sustainable seafood practices include using methods that minimize bycatch, implementing seasonal or area closures to allow fish populations to recover, and using aquaculture methods that minimize the use of antibiotics or other chemicals. Organizations such as the Marine Stewardship Council (MSC) and the Aquaculture Stewardship Council (ASC) work to promote sustainable seafood practices and provide certification for products that meet their sustainability standards. In addition, many retailers and restaurants are now offering sustainable seafood options to their customers, often labeled with a sustainability certification logo to make it easier for consumers to make informed choices. Consumers can also play a role in promoting sustainable seafood by making conscious choices about the seafood they purchase and consume. This can include choosing seafood that is labeled as sustainably harvested or farmed, asking questions about the source and production methods of the seafood they purchase, and supporting restaurants and retailers that prioritize sustainability in their seafood offerings. By working together to promote sustainable seafood practices, we can help to ensure the health and sustainability of our oceans and the communities that depend on them.
Sustainable animal feed.
A study suggests there would be large environmental benefits of using insects for animal feed.When substituting mixed grain, which is currently the main animal feed, insect feed lowers water and land requirement and emits fewer greenhouse gas and ammonia. 
Sustainable pet food.
Recent studies show that vegan diets, which are more sustainable, would not have negative impact on the health of pet dogs and cats if implemented appropriately. It aims to minimize the ecological footprint of pet food production while still providing the necessary nutrition for pets. Recent studies have explored the potential benefits of vegan diets for pets in terms of sustainability.
One example is the growing body of research indicating that properly formulated and balanced vegan diets can meet the