This study 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. This study also provides possible directions for improving current methods and practices of LCA, and for harmonized use of LCA and different systemic approaches. This paper first examines the actual level of complexity of the feedback and pathways within the larger system consisting of food system sustainability and dietary choice, and investigates the interconnection between systems thinking, LCA and circular economy. Then through a systematic review, this study critically evaluates the strengths and weaknesses in the methods and practices of current LCA on the interrelationships among environmental sustainability, food system and human dietary choice. Moreover, this study gives suggestions on improving current methods and practices, and devising more holistic practices through rethinking and applying systems thinking approaches. We suggest using systems thinking, stronger boundary critique, inclusion of broader phases and sustainability indicators, and focusing more on the sustainability impact of consumption-based activities in food life cycle, and further developing selection criteria for indicators to improve the current methods and practices of LCA and circular economy. This paper is expected to facilitate future system dynamic modeling of the interrelationship among environmental sustainability, food system, and human dietary choice and health.

当研究环境可持续性，食物系统和人类饮食选择之间的相互关系时，本研究着重于检查和增强生命周期评估（LCA）和循环经济的现有方法和实践的理论基础和稳健性。这项研究还提供了可能的方向，以改进当前的LCA方法和实践，以及LCA和不同系统方法的统一使用。本文首先研究了由食物系统可持续性和饮食选择组成的较大系统中反馈和路径的实际复杂程度，并研究了系统思维，LCA和循环经济之间的相互关系。然后通过系统的审查，这项研究主要评估了当前LCA方法和实践在环境可持续性，食品系统和人类饮食选择之间的相互关系方面的优缺点。此外，本研究通过重新思考和应用系统思维方法，为改进当前的方法和实践以及设计更全面的实践提供了建议。我们建议使用系统思维，更严格的边界批判，纳入更广泛的阶段和可持续性指标，并更多地关注以消费为基础的活动对食品生命周期的可持续性影响，并进一步制定指标选择标准，以改善当前的方法和实践。 LCA和循环经济。