Beyond body mass index: Body composition in children and adolescents with type 1 diabetes, clinical implications and perspectives

Body composition assessment has emerged as a complement to anthropometric evaluation in children and adolescents with type 1 diabetes (T1D).Accumulating evidence demonstrates that body composition alterations may develop, despite a normal body mass index, highlighting the limitations of body mass index as a standalone metric for detecting metabolically significant changes.This review aims to synthesise evidence on the factors determining body composition, measurement techniques and clinical implications in youth with T1D, focusing on adiposity, lean body mass and fat distribution.Available evidence suggests greater total adiposity in youth with T1D than in healthy peers, whereas lean body mass does not consistently differ between groups.The evidence for central fat distribution is heterogeneous, and direct paediatric data on visceral and ectopic fat remain limited.Predominantly, observational studies have reported associations between body composition measures and glycaemic control, insulin sensitivity, cardiometabolic risk markers and physical fitness.However, their incremental clinical value beyond anthropometry remains to be established.Bioelectrical impedance analysis is a feasible tool for assessing body composition.However, the absence of standardised body composition metrics and limited paediatric reference data limit its clinical implementation.Future longitudinal studies, standardised assessment protocols and reference standards are required to establish how body composition assessment can support individualised paediatric diabetes care.