Association between attention-deficit/hyperactivity symptoms and body composition in children: a health examination-based study

Although attention deficit/hyperactivity disorder (ADHD) has been associated with obesity, research examining specific body composition components and dimensional symptom domains remains limited. This study aimed to investigate the associations between dimensional ADHD symptom domains and specific body composition indicators in children, and to explore potential moderating and mediating pathways. A retrospective cross-sectional analysis was conducted in 636 children aged 6–18 years. ADHD symptoms were assessed using the parent-reported SNAP-IV scale, and body composition (visceral fat area [VFA]; skeletal muscle mass to weight ratio [SMM/WT]) was assessed via bioelectrical impedance analysis. Multiple linear regression examined independent associations, adjusting for age, sex, and BMI z-score. Moderation and mediation analyses tested whether BMI z-score moderated the SMM/WT-symptom link, and whether metabolic markers mediated the SMM/WT-inattention association. Higher SMM/WT was independently associated with lower inattention (β = -0.017, p = .041) and hyperactivity-impulsivity scores (β = -0.018, p = .031). Greater VFA was linked to lower hyperactivity-impulsivity (β = -0.002, p = .048) and oppositional defiant symptoms (β = -0.003, p = .011). BMI z-score showed no independent association with any symptom domain and did not moderate the SMM/WT-symptom relationship (all interaction p > .05). None of the metabolic markers (HDL-C, ALT, AST, fasting glucose) significantly mediated the SMM/WT-inattention association (all indirect effect 95% CIs included zero). Specific body composition components show distinct, symptom-domain-specific associations in children with ADHD, independent of overall weight status. The inverse association of skeletal muscle mass with inattention was not explained by the metabolic markers examined.