New approach for estimating excess body fat from changes in abdominal girth.

A new method is proposed for determining changes in percent body fat (%BF) based on the difference between an initial value for abdominal girth (AG) and a calculated "target" AG based on a desired %BF. Group data from large-scale anthropometric surveys in the military were used to derive specific reference values for Q, defined as the ratio of AG at a desired %BF to F(√BMkg /Htm ). For an individual, Q*F resulted in an AG that corresponded to a desired %BF (set at approximately 20% for males and 30% for females). The method was applied to professional football players, longshoremen, shot-put and weight-lifting athletes, and obese males and females who reduced body mass and altered their body composition. The results showed that changes in AG with body mass loss were proportional to percentage changes in total body fat loss. These relationships permitted extrapolation to a projected target AG that corresponded to a desired %BF. The proposed method differs from the traditional approach that first determines %BF, and then the individual attempts to achieve a desired change in body mass or body composition. The objective of the new method is straightforward; the individual endeavors to attain a target AG that corresponds to a desired %BF.