How to measure the sustainability of diets

A new open access paper outlines for the first time an approach to develop metrics and guidelines to measure the sustainability of diets. It is co-authored by Paolo Prosperi, Institut Agronomique Méditerranéen de Montpellier, Thomas Allen and Bruce Cogill of Bioversity International and Martine Padilla and Iuri Peri of CIHEAM-IAMM and University of Catania, DiGeSA, Italy.

Since the technological innovations of the Green Revolution of the 1960s and 1970s, much attention has been on producing as much food as possible for the lowest cost for the largest number of people. The need to address world hunger and the expected food needs of a growing population, estimated to be around 9 billion by 2050, has driven food security agendas, which have often overlooked the need for food systems to be sustainable.

Yet there is a growing consensus by the international and scientific community that a shift is needed to meet the global challenges that we face today including malnutrition, climate change, degraded lands and the reduction of agricultural biodiversity in our food systems.

The numbers of overweight and obese people in the world tops 2 billion. The increasingly sedentary and urbanized world demands animal source foods and foods that require a higher environmental cost in terms of land, water and fossil fuels. Diet-related non-communicable diseases are taking their toll – for example, in 2000, an estimated 20.8 million people were known to have Type 2 diabetes in China, a number which the World Health Organization predicts to increase to 42.3 million within the next 15 years. In addition, micronutrient deficiencies, known as 'hidden hunger' affect over 2 billion people globally.

Understanding the capacity of food systems to provide food and nutrition security over time, needs to take into account environmental, social and cultural assets and constraints. This shift requires a complex approach that considers each step of the food chain from farm to fork, to agree a common consensus on what is meant by the term 'sustainable diet', and to develop approaches so the sustainability of diets can be measured.

In 2010, following an international scientific symposium organized by Bioversity International and the Food and Agriculture Organization of the UN (FAO), a common definition of what is meant by a sustainable diet was agreed as:

"Those diets with low environmental impacts which contribute to food and nutrition security and to healthy life for present and future generations. Sustainable diets are protective and respectful of biodiversity and ecosystems, culturally acceptable, accessible, economically fair and affordable; nutritionally adequate, safe and healthy; while optimizing natural and human resources".

One of the next priorities agreed was the need to develop metrics and guidelines so that the sustainability of diets can be measured in a way that is useful to inform stakeholders, measure change and aid decision-making processes at regional and national scales. This paper proposed the conceptual framework to do this, using examples and insights from the Mediterranean region to form the basis for wider application.

To move from theory to practice, the following two steps were identified: 

• Establish a conceptual framework
  A framework is needed in order to map out the strengths and weaknesses of a food system to understand related impacts on food and nutrition security, and aid decision-makers and engage stakeholders in a forward-thinking, innovative way. Looking at environmental stress (severe weather, pests and disease outbreaks, climate change, etc.) and societal stress (price volatility, conflict, changing values, etc.), the vulnerability and resilience frameworks allow the dynamics of the food systems to be taken into account.

• Identify indicators and metrics
  An analysis of indicators, that are already in use, was carried out. This analysis focused on those that characterize vulnerability and resilience of food systems, in particular, to stresses such as water depletion, biodiversity losses, price volatility, and changing lifestyle and consumption patterns. It included components that measure how food is produced, transformed, distributed and consumed. To further refine these indicators, interdisciplinary experts participated in focus groups and questionnaires including agronomists, food technologists, nutritionists and economists.

Next steps:

The global shift in what people eat due to demographic, commercial and lifestyle changes is having profound and far-reaching impact for the entire food chain and for the health and well-being of all of us. Producers and consumers need to be part of the solution to achieve sustainable food systems. We are seeing examples of this from consumer groups, some food companies and a small but growing list of countries willing to tackle dietary guidelines based on principles of sustainability. We still need to better understand how the changes in food systems can transform the structure of production systems, and thus the nature and scope of food-related health and environmental issues facing the world.

This paper is part of an ongoing collaborative process drawing upon the expertise of academics, researchers, consumers and policymakers from over 35 institutions throughout the world. There will be a workshop in Montpellier (France) on the 4th and 5th of November 2014, where a panel of international experts will meet to discuss and finalize the list of indicators of sustainable diets and food systems based on the conceptual framework outlined in this paper. More details will be announced on our website soon.

Download the paper:
Sustainability and Food and Nutrition Security: A vulnerability assessment for the Mediterranean Region

For more information, contact:
Email: Thomas Allen or Bruce Cogill

This work has been carried out in collaboration with CIHEAM-IAMM, University of Catania, Montpellier SupAgro, and the support of the Daniel and Nina Carasso Foundation and the CGIAR Research Program on Agriculture for Nutrition and Health.

Photo: Traditional and wild Sri Lankan crops used in cooking. Credit: Bioversity International/S.Landersz