A Systems Analysis of Food Loss and Waste in Nigeria’s Urban Food Supply Chains: Quantification, Economic Valuation, and Policy Interventions

Food loss and waste across Nigeria's urban food supply chains imposes enormous economic, nutritional, and environmental costs that undermine the country's food security objectives and sustainable development commitments. Despite the scale of the problem, robust systems-level quantification and economic valuation frameworks applicable to Nigeria's complex and informal urban supply chain contexts are absent from the literature. This thesis presents a comprehensive systems analysis of food loss and waste across urban food supply chains in three Nigerian cities representing distinct geopolitical zones: Lagos (South West), Kano (North West), and Port Harcourt (South South). A mixed-methods research design integrated primary physical loss measurement at over 200 supply chain nodes using standardised weighing protocols, economic valuation using market price and shadow price methodologies, secondary economic impact modelling using input-output analysis, and qualitative systems mapping with supply chain actors and policy stakeholders. Primary research targeted five commodity systems (tomatoes, leafy vegetables, maize, fish, and bananas) selected by economic and nutritional significance. Total annual food loss and waste across the three cities was estimated at 4.7 million metric tonnes with an economic value of 1.3 trillion Naira. Loss hotspots and their structural drivers were identified at the supply chain level. Systems modelling identified twelve high-leverage policy intervention points. The study produces the most comprehensive food loss and waste quantification effort in urban Nigeria and develops a replicable assessment framework for extension to additional cities. Keywords: food loss and waste, urban supply chains, systems analysis, economic valuation, Nigeria.