The proposed research project aims to investigate sarcopenic obesity (SO), a condition characterized by the combination of high body fat and low skeletal muscle mass, with a focus on muscle function. SO has been defined according to the ESPEN-EASO algorithm, and this study aims to evaluate its validity, exploring associations with circulating biomarkers and functional outcomes. By enrolling 75 subjects with SO and a control sample of 75 subjects with non-sarcopenic obesity, the primary objective of this study is to examine the consistency of the proposed diagnostic criteria with respect to circulating biomarkers and functional outcomes. Secondary objectives include the assessment of additional variables and the detailed profiling of SO subjects through questionnaires and multidimensional tests. The ethical aspect of the present study will be guaranteed through written informed consent and protection of privacy, respecting international regulatory standards. The investigators believe that this work provides significant contributions to the understanding of sarcopenic obesity and to the validation of diagnostic criteria, with possible implications for public health. The investigators are available for further clarifications and approvals required by the Ethics Committee.