As fitness professionals, we are often approached with the question of what is the best, most efficient way of analyzing body fat. There are only a few methods that are applicable in a gym setting: circumference measurement, electrical impedance, and skinfold analysis. Both circumference and electrical impedance have a larger percentage of error, so the blog will compare the accuracies of the Durnin-Womersley four-site skinfold and the Jackson-Pollock seven-site skinfold. While other methods for skinfold measurement exist, these are the two most commonly used.
For our research, we will use six individuals of varying gender, body size, age, and shape to compare the different methods. According to our anthropometric findings, the variation between the four and seven-site, is greatest in females and the largest differential occurs with age. The four-site has a larger fluctuation with older females and this is supposed to account for lower body density resulting in more visceral fat accumulation. Fifty to Seventy five percent of fat is subcutaneous, thus the difference in estimate between methods can only be proportional to the remaining body weight.
According to the American Journal of Clinical Nutrition, select skinfold equations can have a marked overestimation of body fatness. The Jackson-Pollock seven-site skinfold test is known to be more accurate because of the formulation, variation, and quantity of sites being used having a relatively low margin of error in comparison to hydrostatic weight of only 3.3% inaccuracy. A lot of individuals have differing shapes in the lower body region, and none are included in the Durnin-Womersley skinfold test, making it more reliant on estimation.
Regardless, periodic skinfold measurements will give a reflection of change despite the estimate of body fat percent. In other words, doing regular skinfold measurements will still show changes that are occurring.