Comparison of Different Methods Used to Assess Body Composition in College Aged Athletes

Abstract

With the prevalence of obesity increasing to almost 40% as of 2016 and the vast amount of health complications known to be associated with being overweight or obese, knowing one’s body composition is increasingly important. The American College of Sports Medicine has recommended values for % body fat that places individuals into different categories (from very lean to very poor), based on sex and age. However, these categories of % body fat are based on the use of Skinfold Thickness measurements. There are now numerous ways in which to assess body composition and we don’t know the variability that may exist between these methods. PURPOSE: The purpose of this study was to compare the most common methods of measuring body composition that are currently being used today in order to determine- 1) how much of a difference exists between the different techniques, and 2) the relationship of the different methods of measuring body composition. METHODS: Thirty-nine healthy males (age=20±2 y; body weight=97.38±21.26 kg; height=1.79±0.06m) had their body composition assessed five different ways. Prior to each testing day subjects completed a 10-12 hour fast, did not exercise, and had a Urine Specific Gravity of <1.02. Body composition assessments included skinfold (SF) thickness (Lange Skinfold Caliper), Dual Energy X-Ray Absorptiometry (DXA; GE Advanced Prodigy DXA Encore V17 Software), Ultrasound Thickness (US; BodyMetrix), Bioelectric Impedance (BIA; Tanita Body Composition Analyzer, BF-350), and Underwater Weighing (UWW; Exertech Floatweight System). RESULTS: Body fat % for US was 17.62±6.82%, SF 17.69±7.59%, UWW 21.94±8.97%, BIA, 23.64±7.74%, and DXA 24.98±8.63%. In comparison to DXA, % fat was significantly greater than US, SF, and UWW (p<0.001). In respect to the relationship to DXA, correlations ranged from .873 (DXA vs. BIA p=0.001) to .957 (DXA vs SF p=0.001). CONCLUSIONS: These results suggest that a difference in body fat up to 7.36% can be observed between the different methods assessed. However, the relationship between the different methods is fairly strong. Due to the large variability observed in the different body composition methods assessed, it would suggest the need for developing recommended standard ranges based on the body composition assessment utilized.