Osteosarcopenic obesity (OSO) is a clinical and functional condition characterized by the coexistence of osteopenia/osteoporosis, sarcopenia, and obesity (excess adiposity). Currently, the lack of consensus on diagnostic criteria and cut-off values complicates prevalence estimates and limits its potential role as a predictor for various diseases.

This systematic review aimed at examining current definitions and diagnostic criteria adopted in individuals with OSO. A systematic search was conducted on PubMed, Scopus and Web of Science from inception until July 31st, 2024.

Human studies involving all ages, sexes, and ethnicities were included, excluding those lacking well-specified definitions or cut-offs for osteopenia/osteoporosis, sarcopenia and obesity. Results were reported in accordance with the PRISMA 2020 guidelines, with methodological quality assessed using the Quality Assessment Tools of the National Institutes of Health.

After removing duplicates and screening titles and abstracts, 64 potentially eligible studies were examined. Of these, 39 studies involving 118,791 participants met the inclusion criteria.

Significant heterogeneity was observed in the diagnostic approaches, largely due to the variability in parameters and methods used to assess sarcopenia and obesity, and reference cut-offs. This may partly be explained by differences in the availability of body composition techniques across settings, investigators' level of expertise and the study population involved.

These findings underscore the need for consensus guidelines that provide a standardized definition of OSO, diagnostic criteria with practical and clinically relevant cut-offs, and consistent methodologies. This will help identify the prevalence of OSO, define its clinical and functional significance, and develop effective prevention and treatment strategies.