A Delphi approach to develop sustainable food system metrics

Recurrent food crises and global environmental change are critical issues that
pushed food security and sustainability to the top of the policy agenda. Policy-makers
need assessment tools that help them decide what actions they should take to achieve these
goals. This paper proposes a new metric system assessing the sustainability of food systems
and diets at a subnational level adapted to the context of the Mediterranean area. Recogniz-
ing the systemic dimension of sustainability, the proposed information system builds on a
vulnerability/resilience conceptual framework and considers the interactions between a set
of biophysical and socioeconomic drivers of vulnerability and a number of context-specific
food and nutrition security issues. A three-round iterative Delphi survey was conducted
to involve a number of selected experts in the indicator selection process. 18 indicators
were finally identified for eight preselected causal models of vulnerability and resilience at
the interactions between a set of four drivers of change (water depletion, biodiversity loss,
food price volatility, and changes in food consumption patterns) and four food and nutrition
security outcomes (nutritional quality of food supply, affordability of food, dietary energy balance, and satisfaction of cultural food preferences). Each interaction was disentangled
in exposure, sensitivity and resilience. The exercise allowed discussion of a conceptual and
dynamic framework for food systems, and identification of indicators that gather consensus
among the expert community