Mapping the food waste-energy-water-emissions nexus at commercial kitchens: A systems approach for a more sustainable food service sector

A ‘nexus’ approach, comprising interrelated systems components of energy, water, and food, has been suggested to accelerate progress towards achieving sustainable development goals on food waste and related issues, like climate change. The current body of literature usually focuses on food security, especially in relation to production and waste management in the supply chain. The food service sector (FSS), a major consumer-facing component of the food system, has often been overlooked or neglected. There exists, then, an opportunity to better understand the interlinkages between food waste, energy, water, and emissions – the FEWE Nexus – to assist this sector in developing more sustainable operations, such as kitchen equipment management and menu development. To fill this gap, we introduce a novel FEWE Nexus Framework, to understand the flow of nexus components associated with receiving, storing, preparing, cooking, cleaning, and serving menu items. A key aspect of the methodological approach for FEWE evaluation is life cycle assessment (LCA). This is embodied in a comprehensive nexus audit tool comprising several indicators to monitor and quantify energy and water consumption, emissions from cooking, food waste generated, and type and efficiency of equipment used. Further, a stakeholder engagement survey is integrated, allowing for stakeholder feedback on applications of the audit tool, and to assess the impacts and acceptance of potential interventions. Finally, we describe how an iterative nexus approach can enable decision makers in the FSS to robustly estimate nexus components and establish a baseline to track their progress towards minimizing wastages and maximize efficiency.