A Multidimensional Assessment of Food Security in Low- and Middle-Income Countries: System Performance and Interdimensional Coordination

Background: Food security systems are central to nutritional health and Sustainable Development Goal 2 (SDG 2), yet existing assessments have paid limited attention to cross-dimensional coordination within food security systems. This study assessed both system performance and coordination in low- and middle-income countries (LMICs) during 2019–2021. Methods: Based on a multidimensional 25-indicator framework, the entropy-weighted Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) approach was used to evaluate system performance. Spearman’s rank correlation and Bland–Altman agreement analyses against the SDG 2 Index and the Under-Five Mortality Rate (U5MR) were used to examine the validity. The coupling coordination degree (CCD) model was used to assess coordination across the four dimensions of food security: availability, access, utilization, and stability. Results: Among all included LMICs, composite scores ranged from 0.103 to 0.698. Regionally, Europe and Central Asia showed the strongest overall performance (mean = 0.54), whereas Sub-Saharan Africa exhibited the lowest levels (mean = 0.27). The dimensions of access and stability were identified as the principal global bottlenecks of overall food security system development. The proposed index correlated positively with the SDG 2 Index (R = 0.662, p < 0.001) and inversely with the U5MR (R = −0.769, p < 0.001). The coupling degrees were consistently high but exceeded coordination levels across regions, indicating that strong interdependence among dimensions did not necessarily translate into balanced or synergistic system development. Conclusions: Food security systems in LMICs are constrained by weaknesses in the access and stability dimensions, as well as by insufficient cross-dimensional coordination. Strengthening them requires integrated, cross-sectoral strategies that enhance both system performance and interdimensional coordination.