Physical Activity Status and Adiposity-Related Morphological Risk in Children: Differences in Anthropometric, Body Composition, and Somatotype Indicators.

Background/Objectives: Physical inactivity represents one of the most critical public health challenges of recent decades, particularly in pediatric populations. Therefore, this study aimed to evaluate differences in adiposity-related morphological risk indicators between physically active and inactive children by simultaneously integrating anthropometric measures, five-component body composition, and somatotype analysis. Methods: This cross-sectional study included 126 children aged 6-9 years (56 girls and 70 boys). Physical activity status was determined using the Physical Activity Questionnaire for Older Children. Anthropometric indicators included BMI, waist circumference, waist-to-hip ratio, waist-to-height ratio, and conicity index. Adipose and muscle mass, fat mass index, and adipose-to-muscle ratio were estimated using Kerr's five-component model, and somatotype was assessed using the Heath-Carter method. Results: Inactive children showed higher body mass index (BMI), waist circumference, waist-to-hip ratio, waist-to-height ratio, conicity index, adipose mass, fat mass index, sum of skinfolds, and endomorphy, together with lower ectomorphy, than active children (all p < 0.05). Sex-stratified analyses showed that these differences were broader and generally larger among boys. Age-adjusted interaction models also indicated more pronounced active-inactive differences in boys for several central and total adiposity indicators. Conclusions: Physical inactivity was associated with a less favorable adiposity-related morphological profile in children aged 6-9 years, particularly among boys. These findings support complementing BMI with central adiposity indicators, body composition measures, and somatotype analysis in pediatric and school-based assessments, potentially supporting earlier identification of children with unfavorable morphological profiles.