Food systems are often described as comprising four sets of activities: those involved in food production, processing and packaging, distribution and retail, and consumption. All encompass social, economic, political, and environmental processes and dimensions. To analyze the interactions between global environmental change and food systems, as well as the tradeoffs among food security and environmental goals, a food system can be more broadly conceived as including the determinants (or drivers) and outcomes of these activities. The determinants comprise the interactions between and within biogeophysical and human environments that determine how food system activities are performed. These activities lead to a number of outcomes, some of which contribute to food security and others that relate to the environment and other societal concerns. These outcomes are also affected directly by the determinants.
Food security is the principal policy objective of a food system. Food security outcomes are described in terms of three components and their subcomponents: food availability, i.e., production, distribution, and exchange; food access, i.e., affordability, allocation, and preference; and food use, i.e., nutritional and social values and safety. Although the food system activities have a large influence on food security outcomes, these outcomes are also determined directly by socio-political and environmental drivers. These outcomes vary by historical, political, and social context.
To capture these concepts holistically and to allow the analysis of impacts of global environmental change, adaptations, and feedbacks, a food system must include: