Percent body fat estimations in college women using field and laboratory methods : a three-compartment model approach

Background: Methods used to estimate percent body fat can be classified as a laboratory or field technique. However, the validity of these methods compared to multiple-compartment models has not been fully established. This investigation sought to determine the validity of field and laboratory methods for estimating percent fat (út) in healthy college-age women compared to the Siri three compartment model (3C). Methods: Thirty Caucasian women (21.1 ± 1.5 yrs; 164.8 ± 4.7 cm; 61.2 ± 6.8 kg) had their út estimated by BIA using the BodyGram™ computer program (BIA-AK) and population-specific equation (BIA-Lohman), NIR (Futrex® 6100/XL), a quadratic (SF3JPW) and linear (SF3WB) skinfold equation, air-displacement plethysmography (BP), and hydrostatic weighing (HW). Results: All methods produced acceptable total error (TE) values compared to the 3C model. Both laboratory methods produced similar TE values (HW, TE = 2.4út; BP, TE = 2.3út) when compared to the 3C model, though a significant constant error (CE) was detected for HW (1.5út, p ≤ 0.006). The field methods produced acceptable TE values ranging from 1.8 – 3.8 út. BIA-AK (TE = 1.8út) yielded the lowest TE among the field methods, while BIA-Lohman (TE = 2.1út) and NIR (TE = 2.7út) produced lower TE values than both skinfold equations (TE > 2.7út) compared to the 3C model. Additionally, the SF3JPW út estimation equation resulted in a significant CE (2.6út, p ≤ 0.007). Conclusion: Data suggest that the BP and HW are valid laboratory methods when compared to the 3C model to estimate út in college-age Caucasian women. When the use of a laboratory method is not feasible, NIR, BIA-AK, BIA-Lohman, SF3JPW, and SF3WB are acceptable field methods to estimate út in this population.