Abstract
<jats:p>This study examined secular changes in somatotype development among Turkish children and adolescents by comparing age- and sex-specific somatotype patterns derived from two cross-sectional surveys conducted in 2005 and 2017. Standardized anthropometric measurements were obtained from 2,912 schoolchildren aged 6–17 years living in Ankara, the capital city of Türkiye. Data collection was approved by the Turkish Ministry of National Education, and schools were selected to represent lower, middle, and higher socioeconomic strata. Somatotypes were calculated using the anthropometric Heath–Carter method. Secular change in overall physique configuration was quantified using three-dimensional distances between mean somatotype positions, while within-group variability was assessed as the average distance of individual somatotypes from the group mean. Across most age groups, somatotype components differed between survey years, indicating a clear secular shift in body build. Endomorphy was generally higher in 2017, particularly among girls during late childhood and adolescence, whereas boys showed consistently higher mesomorphy across both surveys, with modest increases at several adolescent ages. Ectomorphy declined with age in both sexes and was lower in 2017 compared with 2005. Somatochart analyses revealed overlapping but systematically displaced distributions between cohorts, with pronounced age- and sex-specific variation in the magnitude and heterogeneity of secular change. These findings demonstrate marked secular shifts in somatotype development among Turkish children and adolescents, suggesting a trend toward less linear and more compact body builds in recent cohorts and highlighting the relevance of somatotype-based approaches for monitoring population-level changes in child growth and public health.</jats:p>