This project will comprehensively investigate sarcopenia and sarcopenic obesity in middle-aged and older adults by leveraging the extensive phenotypic, imaging, biomarker, and genetic resources of the UK Biobank. Sarcopenia, defined by the progressive loss of muscle mass and strength, and sarcopenic obesity, its co-occurrence with excess adiposity, are increasingly recognized as major threats to healthy ageing. Both conditions contribute substantially to frailty, falls, disability, cardiovascular and metabolic disorders, cognitive decline, and premature mortality, yet their epidemiology and determinants remain incompletely understood across diverse population groups. This study will examine the prevalence and natural history of sarcopenia and sarcopenic obesity, identify genetic, metabolic, biochemical, lifestyle, and environmental determinants, and evaluate their associations with a wide spectrum of adverse health outcomes. It will further explore potential heterogeneity across subgroups defined by age, sex, socioeconomic status, ethnicity, and comorbid conditions, thereby identifying populations at greatest risk. Building on these insights, advanced statistical modelling and machine learning methods will be applied to develop and validate risk prediction tools, with the aim of improving early identification and prevention strategies. By integrating epidemiological, clinical, and biological perspectives, this research will provide a holistic understanding of sarcopenia and sarcopenic obesity, clarify their impact on morbidity and mortality, and generate evidence that can inform targeted interventions and public health strategies to promote resilience and extend healthspan in ageing populations.
