Study On The Evaluation Method Of Body Composition Of Children And Adolescents

Purpose:Body composition is paid more attention of the researchers when it is regard as a indicator of a direct response to the physical health of children and adolescents.An accurate body composition testing and evaluation methods is significant for the identification of whether an individual obesity or malnutrition.Currently, the Physical Health Standard of many of the world are developed in countries and regions included in the test body composition, but body composition test methods and evaluation of different countries and regions are not entirely unified.By comparing BMI, waist circumference, waist-hip ratio and skinfold four measurement methods for predicting the accuracy of body fat percentage, in order to find the most suitable method for evaluation of body composition in children and adolescents.Mothod:In this study,7-18 years old children and adolescents are the objects.This study analyses and discusses the changes of the composition characterized by composition of the age of these children and adolescents in the body, comparing to four commonly used method for evaluation of body fat percentage, namely BMI, waist circumference, WHR, skinfold thickness, by comparing their respective analysis area under the ROC curve, sensitivity, specificity, and predictive accuracy obtained four methods of body fat percentage, in order to determine which method is more suitable for the evaluation of children and adolescents the percentage of body fat.Results:(1) in boys, BMI, waist circumference, waist to hip skin fold thickness prediction body fat percentage of the ROC curve and the area under the ROC curve were 0.820,0.873,0.632,0.835. Among them waist circumference predict body fat percentage of the ROC curve, the area under the ROC curve for the study of four methods of maximum value;(2) in women, BMI, waist circumference, waist to hip skin fold thickness prediction body fat percentage of the ROC curve and the area under the ROC curve were 0.958,0.787,0.660,0.669. Among them BMI is predictive of ROC curve of body fat percentage, the area under the ROC curve for the study of four methods of the value;(3) ROC curve prediction method of 7-12 various age male body fat percentage in the ROC curve method of waist circumference measurement under the largest area,0.860; ROC curve prediction methods 13-15 age of male body fat percentage in the ROC curve method for the measurement of BMI under the largest area.0.936; ROC curve prediction methods 16-18 age of male body fat percentage in the ROC curve method of waist circumference measurement under the largest area,0.860; ROC curve prediction methods 7-12 age of female body fat percentage in the ROC curve method for the measurement of BMI under the largest area.0.860; ROC curve prediction methods 13-15 age of female body fat percentage in the ROC curve method of skinfold thickness measurement of the largest area under 0.844 kinds of prediction; 16-18 age of female body fat percentage In the ROC curve of the method, the area under the ROC curve of the waist circumference measurement method was the largest, which was 0.800.Conclusion:(1) on the whole, for boys, waist circumference to evaluate the effect of body composition is better, for girls, BMI predict better body composition;(2) for the purposes of different ages, the boys 7-12 years of age, waist circumference predict body composition effect is better, the boys aged 13 to 15 years of age a BMI predict body composition effect better, boys aged 16-18 years old waist circumference predict body composition effect is better; girls 7-12 years of age, BMI is predictive of body composition effect is better, the girls aged 13 to 15 years of age paragraph of skin fold thickness measurement method predicted body composition effect is better, the girls 16-18 years old of age, waist circumference predict body composition effect is better.