Comparison of percentage of body fat in women as measured by the Armed Forces circumference methods, hydrostatic weighing, and skinfold calipers
The purpose of this study was to determine if there was a difference between percentage body fat (%BF) measurements obtained by the United States (U.S.) Armed Forces circumference methods, the field method of skinfold analysis (SF), and the laboratory method of hydrostatic weighing (HSW). The U.S. Armed Forces circumference methods included the Army Circumference Method (ACM), Air Force Circumference Method (AFCM), and Marine Corps Circumference Method (MCCM). This study was also designed to determine which circumference method correlated best with SF and HSW (criterion variable). The subjects in this study consisted of 30 volunteer female subjects aged 21 to 39 years. Height; weight; circumferences at eight sites (neck, biceps, forearm, wrist, waist, abdomen, hips, & thigh); skinfold thicknesses at three sites (triceps, suprailium, & thigh); vital capacity (VC); and underwater weight were measured during one testing session per subject. Body density results for ACM, AFCM, MCCM, skinfold (SF), and hydrostatic weighing (HSW) were converted to %BF after each testing session. Randomized block analysis of variance revealed that there was a significant difference (p $<$.05) between %BF measurements. A Newman-Keuls mean levels post hoc test revealed that HSW was not significantly different (p $<$.05) from AFCM, ACM, and SF, but was significantly different (p $<$.05) from MCCM. Pearson correlation coefficient analysis revealed that the circumference methods and SF significantly correlated (p $<$.05) with HSW. Skinfold (SF) very highly correlated (r =.9132) with HSW, while ACM (r =.8274), AFCM (r =.8246), and MCCM (r =.7726) highly correlated with HSW. In conclusion, concerning the U.S. Armed Forces circumference methods, ACM was not significantly different (p $<$.05) from HSW in terms of the Newman-Keuls mean levels post hoc test, and the Army method demonstrated the highest correlation (r =.8274) with HSW, whereas MCCM was significantly different from HSW and revealed the lowest correlation (r =.7726) with HSW. Based on the results of this study, the Army %BF method is the most valid U.S. Armed Forces circumference method compared to AFCM and MCCM. The Marine Corps %BF method appears to be the least valid circumference method.