Summary
This paper focuses on examining and enhancing the theoretical basis and robustness of existing methods and practices of life cycle assessment (LCA) and circular economy, when studying the interrelationships among environmental sustainability, food systems and human dietary choice.
In this study, 55 selected (of about 1000 peer-reviewed) articles were examined in terms of the research theme, research method, data and system boundary, and indicators of sustainability of food systems and healthfulness of diet. The strengths and limitations of those articles are processed statistically using meta-analysis.
The authors found out that there are an increasing number of scientific articles focusing on the relationship between environmentally sustainable food system and dietary recommendations, considering health, environmental, social and economic factors as a whole. Studies have found that, generally, a diet that is healthier is also likely to be environmentally sustainable.
The authors examined the interconnections of system thinking, circular economy and LCA. Through the study of the reviewed articles, the strengths and the limitations of these methodologies are discussed. Moreover, based on meta-analysis, both the strengths and limitations of current studies of LCAs and circular economy on food systems tend to be evident. Regarding the strengths, it is clear that the LCA studies have progressed so far and some practices have become near standards, such as using phases of cycle of food systems to help define system boundaries, and the selection of indicators for assessment in the LCAs. Those practices, especially the popular use of Green-House Gas (GHG) emissions as the indicator in LCAs, have apparent advantages such as straightforwardness, and allowing the sustainability of food systems to be more tangible and quantifiable, and thus comparable across different assessments. However, the limitations that come with those advantages are obvious as well. Practices like those, sacrifice both accuracy and diversity of the indicators, reduce the assessment of environmental impacts to (sometimes) only GHG emissions, land use and water use, and make LCA diverge from its initial aim of being a more holistic assessment method.
A revised boundary critique in LCAs of food systems, to include more phases in the cycle of food systems as well as sustainability indicators and be more holistic and pay more attention to system-wide issues, will help improve the current LCA practices.
The authors suggest using systems thinking, stronger boundary critique, inclusion of broader phases and sustainability indicators, focusing more on the sustainability impact of activities at consumer end in the food life cycle, and further developing selection criteria for indicators to improve the current method of LCAs and circular economy.
Relevance for Complex Systems Knowledge
This paper deals with system thinking and sustainable development. This study gives suggestions on improving current methods and practices of life cycle assessment (LCA) and circular economy, devising more holistic practices through rethinking and applying systems thinking approaches. In this way, this study helps improve the tools and methods for promoting the sustainable development of food systems and diet.
