Metabolic syndrome (MetS) and cardiovascular disease have become major global public health issues, with traditional anthropometric indices exhibiting significant limitations in assessing metabolic health. The fat-to-muscle mass ratio (FMR), as a novel body composition index that obviously reflects the relative status of fat load and muscle reserve in the body, has emerged as a research focus in metabolic risk assessment due to its non-invasive and easily measurable advantages. This review systematically summarizes the evidence on the association of FMR with abnormal glucose metabolism, insulin resistance and MetS, explains the biological mechanism of FMR affecting cardiacmetabolic risk, analyzes the limitations of existing studies and puts forward the future research direction. It aims to provide a reference for translating FMR from basic research to clinical application and promoting precision prevention and control of cardiometabolic diseases.

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