Determination of Body Fat Ratio Standards in Children at Early School Age Using Bioelectric Impedance

Abstract

Background and objectives: Body mass index (BMI) is commonly used to assess the proportionality of body mass; however, there are currently no standards for assessing the weight status of the child population for the needs of epidemiological studies. This study aims to establish bioelectric impedance analysis (BIA) standards for assessing the body weight of children (body fat, visceral fat) using BMI percentile growth charts. Materials and Methods: The study was implemented in a group of 1674 children (816 boys and 858 girls), ages 6 to 11. To classify the subjects at a percentile level, the percentile growth charts from the 6th national anthropological study in the Czech Republic were used. Body composition parameters were ascertained by BIA. Results: Body fat (%) and visceral fat standard values were determined for all age categories. The standards were in three-stages, enabling the determination of underweight, normal weight and overweight children aged 6-11 years. For boys with proportionate body mass, standard body fat values ranging from 14.3-16.0% to 15.5-18.0% were determined, while for girls' values ranging from 16.7-19.4% to 18.3-20.5% were determined, depending on age. As far as visceral fat is concerned, standard values in boys ranging from 30.3-36.9 cm² to 36.1-44.9 cm² and in girls 30.3-36.9 cm² to 36.1-44.9 cm² were determined, depending on age. Conclusions: Standards for assessing weight status are applicable to children aged 6-11 years, while it can be confirmed that BMI can be considered as an objective tool in assessing body mass and body composition in children.

Keywords: body fat; body mass index; growth chart; prepubescent children; standards.

Figure 1

BMI percentile growth chart for boys—6th NAS [14].

Figure 2

BMI percentile growth chart for girls—6th NAS [14].

Figure 3

Development of body height and body mass in children in percentile bands P₂ and P₃.