This study investigates the prevalence of sarcopenia and sarcopenic obesity (SO) and their association with all-cause mortality in older adults. Using data from the Rotterdam Study, researchers analyzed 5888 participants aged 69.5 years on average, with a BMI of 27.5. They found that 11.1% had probable sarcopenia, 2.2% had confirmed sarcopenia, 5.0% had SO with one altered body composition (BC) component, and 0.8% had SO with two altered BC components. Participants with SO, especially those with two altered BC components, had a significantly higher risk of all-cause mortality compared to those without SO. The risk was even higher in individuals with a BMI of 27 or greater. Sarcopenia and SO were independently associated with increased mortality risk, regardless of age, sex, and BMI. The study highlights the importance of early identification of sarcopenia and SO through low muscle strength as a diagnostic criterion to prevent premature mortality in older adults. The findings suggest that screening for muscle function may help in the early detection and management of these conditions, which are prevalent and linked to poor health outcomes. The study also emphasizes the need for further research to understand the complex interactions between sarcopenia, obesity, and other factors that contribute to mortality in older adults.This study investigates the prevalence of sarcopenia and sarcopenic obesity (SO) and their association with all-cause mortality in older adults. Using data from the Rotterdam Study, researchers analyzed 5888 participants aged 69.5 years on average, with a BMI of 27.5. They found that 11.1% had probable sarcopenia, 2.2% had confirmed sarcopenia, 5.0% had SO with one altered body composition (BC) component, and 0.8% had SO with two altered BC components. Participants with SO, especially those with two altered BC components, had a significantly higher risk of all-cause mortality compared to those without SO. The risk was even higher in individuals with a BMI of 27 or greater. Sarcopenia and SO were independently associated with increased mortality risk, regardless of age, sex, and BMI. The study highlights the importance of early identification of sarcopenia and SO through low muscle strength as a diagnostic criterion to prevent premature mortality in older adults. The findings suggest that screening for muscle function may help in the early detection and management of these conditions, which are prevalent and linked to poor health outcomes. The study also emphasizes the need for further research to understand the complex interactions between sarcopenia, obesity, and other factors that contribute to mortality in older adults.