At a time when interest in the sustainability of food is increasing, the need for well-defined, interdisciplinary metrics of the sustainability of diets is evident. In this study, a group of researchers from Michigan performed a systematic literature review of empirical research studies on sustainable diets to identify the components of sustainability that were measured and the methods applied to do so.
The authors cite the following definition created at the International Scientific Symposium on Biodiversity and Sustainable Diets (2010):
“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”
This broad definition is comprehensive and contains at least 10 main components and a multitude of subcomponents. The authors note the challenge of translating this framework into dietary and policy recommendations. In particular, operational challenges such as a lack of clear metrics and a shared approach to measuring the multiple components of sustainable diets are lacking. They argue that this has hindered progress towards:
- generating the evidence needed to ensure the credibility of recommendations,
- tracking the influence of new guidelines, and
- formulating and implementing relevant policies.
In the study they systematically review the empirical research literature,identify 30 equally weighted components of a sustainable diet and emphasise ‘the multiscaled political, economic, and ecological contexts that constrain or facilitate changes in diets and food systems.’ Importantly, they find that many of the social and cultural components of the sustainable diet are underrepresented in the research, whereas the global warming potential and the land, energy, and water use of diets was very frequently measured.
Sustainability has become an integral consideration of the dietary guidelines of many countries in recent decades. However, a lack of clear metrics and a shared approach to measuring the multiple components of sustainable diets has hindered progress toward generating the evidence needed to ensure the credibility of new guidelines. We performed a systematic literature review of empirical research studies on sustainable diets to identify the components of sustainability that were measured and the methods applied to do so. Two independent reviewers systematically searched 30 databases and other sources with the use of a uniform set of search terms and a priori exclusion criteria. In total, 113 empirical studies were included in the final review. Nearly all of the studies were focused on high-income countries. Although there was substantial heterogeneity in the components of sustainability measured, the estimated greenhouse gas emissions (GHGEs) of various dietary patterns were by far most commonly measured (n = 71 studies). Estimating the GHGEs of foods through various stages of production, use, and recycling with the use of the Life Cycle Assessment approach was the most common method applied to measure the environmental impacts of diets (n = 49 studies). Many components of sustainable diets identified in existing conceptual frameworks are disproportionately underrepresented in the empirical literature, as are studies that examine consumer demand for sustainable dietary alternatives. The emphasis in the literature on high-income countries also overlooks the production and dietary alternatives most relevant to low- and middle-income countries. We propose 3 methodological and measurement approaches that would both improve the global relevance of our understanding of sustainable diets and attend more completely to the existing multidimensional, multiscale conceptual framing of sustainable diets.
Jones, A.D., Hoey, L., Blesh, J., Miller, L., Green, A., Fink Shapiro, L., (2016) A Systematic Review of the Measurement of Sustainable Diets. Advances in Nutrition 7: 641-664 doi: 10.3945/an.115.011015
Find the full article here (paywall).
The FCRN has published a report called ‘What is a sustainable healthy diet?’ which you can find here. Another resource you might be interested in is Tara Garnett’s recent article in Science.
24 Oct 2016
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