Reducing food loss and waste contributes to energy, economic and environmental sustainability. This study quantifies food loss and waste (FLW) in the UK horticulture supply chain, estimating annual FLW at 2.4 million tonnes, representing 36% of total supply. FLW contributes 1.7 million tonnes of CO₂e annually, accounting for 27.2% of total emissions from the fresh produce supply chain. FLW is driven by economic factors such as labour shortages and price protectionism, and the lack of economic incentives for FLW recovery. The study highlights the environmental impact of FLW, including energy demand and greenhouse gas emissions, and emphasizes the need for a holistic approach to mitigate FLW, including policy and consumer-level changes, and the development of novel postharvest management strategies. The study also identifies the need for improved cold chain management and the potential for warmer storage temperatures to reduce energy demand. The findings suggest that FLW reduction is critical for achieving sustainability goals, and that current economic and environmental drivers may conflict, requiring coordinated action. The study concludes that a multidisciplinary approach is necessary to address the complex nexus between energy, food loss and waste, and sustainability. The research provides new evidence to address the drivers of FLW generation and its environmental impacts.Reducing food loss and waste contributes to energy, economic and environmental sustainability. This study quantifies food loss and waste (FLW) in the UK horticulture supply chain, estimating annual FLW at 2.4 million tonnes, representing 36% of total supply. FLW contributes 1.7 million tonnes of CO₂e annually, accounting for 27.2% of total emissions from the fresh produce supply chain. FLW is driven by economic factors such as labour shortages and price protectionism, and the lack of economic incentives for FLW recovery. The study highlights the environmental impact of FLW, including energy demand and greenhouse gas emissions, and emphasizes the need for a holistic approach to mitigate FLW, including policy and consumer-level changes, and the development of novel postharvest management strategies. The study also identifies the need for improved cold chain management and the potential for warmer storage temperatures to reduce energy demand. The findings suggest that FLW reduction is critical for achieving sustainability goals, and that current economic and environmental drivers may conflict, requiring coordinated action. The study concludes that a multidisciplinary approach is necessary to address the complex nexus between energy, food loss and waste, and sustainability. The research provides new evidence to address the drivers of FLW generation and its environmental impacts.