Comparison of Body Mass Index (BMI) and fat percentage criteria classification of 7-13 year old rural boys in the Eastern Cape, South Africa
Abstract Background: The aim of this paper is to investigate whether BMI and fat percentage classification criteria, would classify a sample in similar criteria’s. Methods: A cross-sectional study with a stratified random sampling included 602 rural boys (7–13 years old). Fat percentage criteria classification and BMI was measured Maturity, age and peak height velocity (PHV) were indirectly determined. Statistical techniques included descriptive, Pearson product correlation, the Kappa agreement test and the McNemar’s test. The level of statistical significance was set at p ≤ 0.05. Results: All age groups presented statistically significant high correlations between BMI and fat percentage, and low to medium correlations between fat percentage and maturity age (MA). Measurement of agreement between BMI and fat percentage classifications showed poor to fair agreements for all age groups, with the exception of the eight-year old group which presented a moderate agreement. Conclusion: Classifications according to BMI and fat percentage, results in different classifications for the same population. Classifications for categorizing purpose should make use of adiposity rather than BMI, as it includes fat free mass within the assessment protocol.