Any system that is a complex set of elements working together as complementary and mutually enabling parts of an interconnecting network. A functioning system is guided by a set of principles or procedures that, when observed, continually accomplish an intended objective.
The objective of a food system is to accomplish the functions that sustain the human relationship to food. Consideration has conventionally been limited to functions that lie along a value or supply chain, such as planning, production, processing, handling, preparation, storage, distribution, consumption and waste.
However, a holistic understanding of food systems goes beyond a limited inventory of mechanical, value and supply chain functions, which are often expressed only in monetary or other quantitative measure. Sustaining the human relationship to food also demands functions that serve the well-being of people and planet. Food systems embody a combination of social, political, environmental, cultural, economic and technical dimensions, the consequences of which bear on the universal human need and, therefore, respect, protect and fulfill the human right to adequate food and nutrition. The combination of these and other food-related functions forms a synergy whose outcome is the food system.
Whereas a (value or supply) chain is a linear and finite system, the sustainability criterion of any (food) system seeks to be self-perpetuating. Sustainable food systems require the preservation of soil, seeds, water and other natural resources through practices such as agroecology; laborers who are willing and able to safely carry out food-related activities; consumers who are able to access food (financially or otherwise); and the production of outputs that will support and sustain the health, nutrition and well-being of its laborers (producers and other workers) and consumers.
Food systems involve also the complex interactions along webs of activities, actors, processes and environments that serve and support multiple public objectives within socio-cultural and ecological domains. These public objectives are defined within the regulating legal and political criteria and methodology of the human right to food and sustainable development, conducted as a duty of states and their successive governments. (See Obligation and Sustainable development)
Since food is essential to human sustenance, this wider system approach likewise encompasses livelihoods, the ecosystem and various determinants of human health. The vital importance of food to human sustenance requires the food system to satisfy individual (nutritional) and collective (social) requirements.
A food system is typically subject policy interventions in at least five principle domains: governance, protection and regeneration of nature, health and wellbeing, modes of food production, exchange and employment; and culture, social relations and knowledge. Beyond food, coherent policy directs change and transformation also in the fields of health, water and sanitation, climate and environment, finance, trade and investment, and social protection to combat hunger and malnutrition.
An evaluation of a food system, therefore, should assess the quality of the corresponding inputs, transactions and outcomes. Thus, a food system can be examined through the lens of inter-related and indivisible human rights, including the anticipation of, and response to human needs, social justice and adherence to inherent values of human dignity, as well as cultural identity, equity, sustainability, sovereignty and the over-riding principles of human rights implementation. (See also Over-riding principles)
Food systems are constantly being shaped by multiple forces, drivers and decisions, and their operation, management, monitoring and evaluation require acknowledgement of the immense power imbalances present in today’s food systems. The city-region and territorial approaches consider food systems across the rural-urban continuum, acknowledging that resilient, sustainable, and people-centered food systems must encompass cities and human settlements, peri-urban and rural areas as complementary parts. Sustainable and healthy food systems are especially vital in the case of natural and man-made crises, which calls for the holistic approach to prepare for such contingencies throughout the food system, beginning with the planning process to anticipate and respond to the individual and collective human need for food and nutrition.
 Committee on World Food Security (CFS), "Policy Roundtable on Food Losses and Waste in the Context of Sustainable Food Systems,” 17 October 2014, at: https://www.hlrn.org/img/documents/Final%20decision%20box%20food%20loss%20and%20waste.docx.
 Committee on Economic, Social and Cultural Rights (CESCR), General Comment No. 12: The Right to Adequate Food (Art. 11), E/C.12/1999/5, 12 May 1999, at:
 Civil Society and Indigenous People’s Mechanism (CSM) Food Security and Nutrition Working Group, "Vision Document on the Voluntary Guidelines” (2019), at: http://www.csm4cfs.org/wp-content/uploads/2016/02/CSM-vision-document-FS-N_draft-June-2019-final.pdf.
 Civil Society and Indigenous People’s Mechanism (CSM), Food Security and Nutrition Working Group, "Vision Document on the Voluntary Guidelines” (2019), pp. 1–2, at: http://www.csm4cfs.org/wp-content/uploads/2016/02/CSM-vision-document-FS-N_draft-June-2019-final.pdf.
 Alison Blay-Palmer, Guido Santin, Marielle Dubbeling, Henk Renting, Makiko Taguchi and Thierry Giordano, "Validating the City Region Food System Approach: Enacting Inclusive, Transformational City Region Food Systems,” Sustainability (May 2018), at: https://www.mdpi.com/2071-1050/10/5/1680/pdf; . UN Committee on World Food Security, "Addressing Food Security and Nutrition in the Context of Changing Rural-Urban Dynamics: Experiences and Effective Policy Approaches” (2019), at: http://www.csm4cfs.org/wp-content/uploads/2016/02/CFS_Addressing_FSN_in_the_context_of_changing_rur_urb_dynamics_experienc….pdf.
 UN Committee on World Food Security, "Addressing Food Security and Nutrition in the Context of Changing Rural-Urban Dynamics: Experiences and Effective Policy Approaches” (2019), at: http://www.csm4cfs.org/wp-content/uploads/2016/02/CFS_Addressing_FSN_in_the_context_of_changing_rur_urb_dynamics_experienc….pdf.