Insights into Metabolically Healthy Obesity-A Narrative Review.

Background: Obesity is a heterogeneous condition with variable cardiometabolic risk (CMR). The concept of metabolically healthy obesity (MHO) challenges the traditional paradigm that excess adiposity is invariably associated with metabolic dysfunction. However, its clinical validity remains controversial. Methods: A comprehensive literature search was conducted in PubMed, Scopus, Web of Science, and Google Scholar, primarily covering studies published between 2020 and 2025, with landmark earlier studies included when relevant. Results: Traditional definitions of MHO rely predominantly on metabolic parameters and fail to capture residual cardiovascular risk (CVR). Individuals with obesity frequently exhibit discordance between low-density lipoprotein cholesterol (LDL-C) and atherogenic particle burden, reflected by elevated apolipoprotein B and remnant lipoproteins. Visceral adiposity and reduced skeletal muscle mass further contribute to metabolic dysfunction. Cardiorespiratory fitness emerges as a major determinant of cardiometabolic resilience, independently associated with reduced mortality. Conclusions: Current evidence suggests that although some individuals may maintain metabolic health over extended periods, MHO frequently represents a dynamic phenotype that may progress toward metabolic dysfunction over time. An integrated approach incorporating lipid burden, body composition, and functional capacity enables more accurate CVR stratification and supports phenotype-based personalized strategies.