Variability in body fat measurements

Abstract

Obesity has reached epidemic proportions with serious health consequences. Techniques used to measure body fat (BF) yield variable BF estimates, and this variability may lead to underestimation of BF and subsequent treatment options. The measurements that are most accurate (Dual-Energy X-ray Absorptiometry (DEXA) and Air Displacement Plethysmography (ADP)) are expensive and often unavailable. The purpose of this study is to find the commonly available BF measurement that is the most accurate and practical for individual body types by comparing these measurements to ADP (BodPod®) as the standard. Measurements include skinfolds (SKF), upper, lower, and whole body bioelectrical impedance (BI), waist and hip circumference ratios, body mass index calculations (BMI), and ADP. Our data indicate that BI is the least accurate measurement of body fat in males and females (paired t-tests of % body fat: BI vs. ADP, p<0.05). Currently used SKF equations, both 7-site and 3-site, are most accurate for their respective genders (paired t-tests of % body fat: SKF vs. ADP, p>0.05). However, preliminary data suggest female-specific SKF equations more accurately predict body fat in obese males than male-specific SKF equations. Given the current obesity trends, it is imperative to update these formulae to accurately reflect the current population. Supported by WSU's UROP (BLR) and a WSU Women in Science Giving Circle Grant (LKH).