Sarcopenic obesity (SO) is a new clinical phenotype of obesity attracting an increasing interest due to its health consequences in an aging population. It generates an increased risk of comorbidities and metabolic disturbances whose etiopathogenic mechanisms are multifactorial and not only linked to aging. It is characterized by the accumulation of fat and loss of muscle mass and function, indicative of potential malnutrition. Diagnostic advances are based on a recent consensus emphasizing the relevance of considering adiposity, strength and muscle mass with specific criteria depending on populations specificities. Its prevalence also varies, largely dependent on age and diseases. Its multifactorial pathophysiology illustrates that sarcopenia can increase adiposity, which can itself promote the development of muscle loss. In terms of management, multidisciplinary approaches combine modifications in dietary intake, targeted exercise and possible pharmacological interventions to prevent, slow or reverse the progression of SO, but randomized controlled trials remain rare in the field. In conclusion, SO is emerging as a critical health issue requiring better characterization and deepening of its development mechanisms. (c) 2023 Societe francophone nutrition clinique et metabolisme (SFNCM)