This dissertation evaluates sustainability within food supply chains (FSCs), addressing the critical need for comprehensive assessment tools. The food industry plays a significant role at the social level and, at the same time, an important part in global environmental degradation, deforestation, greenhouse gas emissions, and freshwater consumption. Food supply chains, particularly in meat and fish products, demand significant energy inputs, presenting multiple challenges for sustainability. Current methodologies for assessing sustainability in food supply chains often neglect the multidimensional nature of sustainability, primarily focusing on environmental aspects and overlooking economic and social dimensions. This research integrates a Life Cycle Thinking approach to holistically assess food supply chains' environmental, economic, and social impacts. The study proposes a methodological framework combining Life Cycle Assessment, Life Cycle Costing, and Social LCA. Case studies from beef and fish cold supply chains evaluate baseline scenarios and energy efficiency measures, including anaerobic digestion and renewable energy integration. Results demonstrate the substantial environmental and economic benefits of these measures, particularly in reducing carbon footprints and improving energy use efficiency through the circular economy and industrial symbiosis principles. The doctoral thesis highlights the need for flexible and context-specific LCA boundaries, enabling tailored energy efficiency interventions in food supply chains. A developed Life Cycle Sustainability Tool further supports supply chain managers and decision-makers by providing precise inventory data and visual outputs, integrating economic values like Net Present Value and Internal Rate of Return. This tool has been validated through practical case studies, proving its effectiveness in evaluating and improving sustainability in food cold supply chains. In conclusion, the dissertation provides a roadmap for policymakers and industry stakeholders to achieve sustainability transformations by bridging the gap between theoretical concepts and practical applications. The document consists of five main chapters. Chapter 1 provides an introduction, outlines the research hypothesis, main objectives, as well as the topicality of sustainability evaluations in different sectors. An extensive literature review exploring food supply chains' environmental impacts and the current sustainability assessment methods. Chapter 2 provides an extensive literature review, exploring the environmental impacts of food supply chains and the current sustainability assessment methods. It discusses the limitations of existing tools and introduces the need for a holistic, lifecyclebased approach to address these gaps. Chapter 3 outlines the methodology, including the development and integration of LCA, LCC, and S-LCA within the context of the food supply chain. This chapter details the selection parameters for case studies and main methodological choices within food cold supply chain cases. Chapter 4 presents the results and analysis of the case studies, focusing on the environmental and economic impacts of EEMs in beef, fish, and egg supply chains. The findings highlight the significant potential of circular economy strategies in reducing energy consumption and enhancing sustainability. 5 Chapter 5 introduces the life cycle sustainability tool (LCST) and explains its practical application for decision-makers. The chapter discusses how the tool integrates key performance indicators, visual outputs, and economic metrics to guide policy and industry-level decisions. Chapter 6 concludes the dissertation by summarizing the key findings and offering recommendations for future research and policy implementations to enhance the sustainability of food supply chains.