Beyond production and consumption: Waste food recycling emerges as the systemic constraint in Iran’s circular food economy

Transitions toward a circular food economy (CFE) remain poorly understood in data-scarce developing contexts. This study presents the first subnational efficiency assessment of Iran’s CFE across 31 provinces (2017–2022), adapting the Modified Dynamic Three-Stage Circular DEA framework to provincial governance units. To address severe data limitations, key variables, including food waste, recycling rates, and GHG emissions, were reconstructed using proxy-based, literature-grounded allocation rules. Results reveal stark spatial disparities: while top-performing provinces (e.g., Khuzestan, Bushehr, Tehran) achieve full efficiency (1.0), over half score below the national mean (0.67), with northwestern and southeastern provinces lagging (< 0.5). Critically, the waste recycling stage is identified as the systemic bottleneck (mean efficiency = 0.40), driven primarily by excessive energy use and high CH₄/CO₂ emissions. Even provinces strong in production or consumption exhibit low recycling efficiency, underscoring its nationwide vulnerability. Governance entry points are highlighted, including the prioritization of decentralized composting and biogas systems, optimization of fertilizer use to reduce NH₃ leakage, and province-tailored interventions based on efficiency profiles. Beyond Iran, the methodological approach offers a transferable framework for circularity assessment under data constraints—providing actionable insights for sustainability planning in the Global South.