Introduction/background Increased body fat is related to obesity and its comorbidities later in life. To determine the amount of body fat in children and adolescents, reference intervals should be applied. Dual-energy X-ray absorptiometry (DXA) is a good tool for accurately measuring body composition. Methodology The body composition reference ranges in Korean children and adolescents were determined using nationally representative cross-sectional data. The performances of the body mass index (BMI) and tri-ponderal mass index (TMI) in measuring body fat were compared using the reference percentiles derived from this analysis. Results A total of 1,661 subjects (891 boys and men and 770 girls and women) were included. Age- and sex-specific percentiles and the corresponding LMS variables for DXA-assessed parameters for the whole body and the trunk were determined. The coefficients of determination of the whole body FM SDS and FMI SDS for the BMI SDS were 0.783 and 0.784, respectively, and those for the TMI SDS were 0.685 and 0.769, respectively. Conclusion Based on the reference values for body composition, the correlation coefficients of TMI for adjusted FM measured by DXA were comparable to those of BMI. TMI estimated body fat levels more accurately than BMI in this study population.

简介/背景体脂增加与肥胖及其晚年合并症有关。为确定儿童和青少年的体脂量，应采用参考区间。双能X射线吸收测定法（DXA）是准确测量身体成分的好工具。方法韩国儿童和青少年的身体成分参考范围是使用具有全国代表性的横断面数据确定的。使用从该分析得出的参考百分位数比较了体重指数 (BMI) 和三重体重指数 (TMI) 在测量体脂方面的表现。结果总共包括 1,661 名受试者（891 名男孩和男性以及 770 名女孩和女性）。确定了全身和躯干的年龄和性别特定百分位数和相应的 DXA 评估参数的 LMS 变量。全身FM SDS和FMI SDS对BMI SDS的决定系数分别为0.783和0.784，对TMI SDS的决定系数分别为0.685和0.769。结论基于身体成分的参考值，DXA 测量的调整 FM 的 TMI 相关系数与 BMI 具有可比性。在该研究人群中，TMI 比 BMI 更准确地估计身体脂肪水平。