Comparison between Bioelectrical Impedance Analysis and Body Mass Index Methods in Determination of Obesity Prevalence of Chinese Preschoolers

Abstract

The incidence of obesity is increasing worldwide. Body mass index (BMI) is a common method of diagnosing obesity, but research on judging the appropriate body weight of Chinese children aged 3–6 years is still lacking. Bioelectrical impedance analysis (BIA) is a safe, accurate, reliable and inexpensive method for screening overweight and obesity. The objectives of this research were to reveal the consistency between BMI and BIA in assessing the obesity characteristics of children aged 3–6 years. In this study, preschool boys (n = 392) and girls (n = 309) aged 3–6 years were recruited from kindergartens in Zhejiang province of China, and a survey of BMI and BIA, which was measured by InBody J20, was completed. BMI and BIA were analyzed by Pearson correlation analysis and linear regression analysis. The linear relationship between rates and a regression equation were established by using the Kappa coefficient to test the consistency between BMI and body fat percentage. The BMI of boys and girls decreased from 19.2 ± 4.9 and 18.1 ± 2.4 at the age of 3 to 14.1 ± 3.3 and 15.1 ± 3.3 at the age of 6 and showed a downward trend as age increased. The correlation between BMI and body fat percentage was 0.533 for boys and 0.539 for girls. The Kappa coefficient test results of BMI and body fat percentage showed that Kappa value = 0.339, p < 0.05, indicating that the diagnostic results of BMI and body fat percentage were consistent, but the consistency was general.

Keywords

• body fat percentage
• body mass index
• bioelectrical impedance analysis
• obesity in preschoolers