Percent Body Fat and Abdominal Circumference Cutoff Points Accounted for 85th and 95th Percentile of Body Mass Index in One City of Gyeonggi Province

ABSTRACT

BACKGROUND: Childhood obesity is becoming more prevalent, associated with a variety of adverse consequences which leads to adulthood obesity. Although diagnosis is usually made by body mass index, there is neither a cutoff point for the percentage body fat nor abdominal circumference. The aim of this study was to identify each cutoff point for both measures. METHODS: The measurement of height, weight, abdominal circumference and percentage body fat was performed through manual assessment and bioelectrical impedance analysis for 4,242 subjects aged 11 in Gunpo City, South Korea. The cutoff point for body fat percentage and abdominal circumference is set to maximize the sum of sensitivity and specificity for detecting obesity and overweight using the Receiver Operating Characteristics (ROC) curve. RESULTS: The mean percentage body fat was 13.6+/-6.9% for boys and 19.4+/-5.3% for girls. The mean abdominal circumference of boys was 68.0+/-9.1 cm, and that of girls was 64.3+/-7.7 cm. The cutoff point of percentage body fat for obesity was 21.8% in boys and 24.5% in girls. The prevalence of obesity was 15.2%, 16.7% for males and females, respectively. The abdominal circumference cutoff for obesity was 76.9 cm in boys and 70.7cm in girls. Based on that, the prevalence of obesity was 19.7% for boys and 20.0% for girls, which was higher than what was identified by body mass index, as in the case of body fat percentage. CONCLUSION: The cutoffs of body fat percentage and abdominal circumference in one city of Gyeonggi Province were lower than those suggested in the previous studies.