Urban food and nutrition systems
food and nutrition system
the set of operations and processes involved in transforming raw materials into foods and transforming nutrients into health outcomes, all of which functions as a system within biophysical and sociocultural contexts. (Sobal, et al. 1998)
The global taco
from 'Permaculture: A Beginners Guide' by Graham Burnett
How do we measure effectiveness of urban food systems? • Health equity dimension • Sustainable urban food systems “3 days’ supply”
Portland Regional Food Economy
• • • • • • •
Production Transport Processing Transport Retail Preparation Waste
• • • • • • • • takes a holistic perspective in examining system boundaries, delineating subsystems and their relationships considering relationships between systems Systems are viewed as sets of elements that function together as collective units. Boundaries exist between a system and its environment Systems may be more or less open or closedbecause of varying permeabilities Whole systems have properties greater than the sum of their component part Subsystems exist within systems. Systems are dynamic, with homeostatic processes that attempt to maintain stability when a change in one part of the system influences other portions of the system or adjustment to external influences occurs Materials, energy and information flow between parts of a system and its subsystems and between the system and its environment the concept of equifinality describes how an end state can be reached from different initial states through many possible paths
Models of food systems
• • • • Food chain Food cycle Food web Food context
Not three different types of systems but three different ways of understanding systems
• • • Food chain models focused on the flow of materials or objects through a sequence of steps, emphasizing movement and transformation through a series of stages that are often ordered and linear. often conceptualized as a stream or series of streams with different channels that interlink
• • Food cycle models focus on feedback within the food and nutrition system, considering how objects and information link back across different stages or levels Food cycle models are used to address concerns about the outputs at each level of the system, especially how waste products accumulate and influence the operation of prior steps – short feedback loops, such as the buildup of waste products in a field and consequent lowering of crop yields – larger feedback loops, such as the water cycle entering and leaving the food and nutrition system. Food cycle models help conceptualize the entire ``life cycle'' of foods and nutrients, examining how stages link back to prior stages.
• • Food web models are network models that focus on the interrelationships among diverse nodes in the operation and control of the food and nutrition system used to show particular relationships between many and often distant points of food and nutrition systems, and the relationship of those points to other important points inside and outside the system
• • Food context models take an ecological perspective focusing on relationships of the food and nutrition system with its environments, which are made up of many other systems Contexts for the food and nutrition system include both the physical and social environments and the other systems that exist in these environments.
Three subsystems of the food and nutrition system
Three subsystems • Producer • Consumer • Nutrition The nutrition system is contained within the human body. The other two are distributed across external space Each subsystem has three stages • Input • Transformation • output
The producer subsystem
• • • • transforms...
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