Which body fat measurements are considered the most accurate and why?

Question

What will be an ideal response?

Answer 1

Answers will vary.

To measure body fat content accurately using typical methods, both body weight and body volume must be measured. Body weight is easy to measure. Of the typical methods used to estimate body volume, underwater weighing is 1 of the most accurate (2 to 3% error margin). This technique determines body volume by measuring body weight when under water and body weight in air and entering these values into a mathematical formula that accounts for the differences in the relative densities of fat tissue and lean tissue (Fig. 10-9). Air displacement, another method for determining body volume, measures the space a person takes up inside a small chamber, such as the BodPod® (Fig. 10-10). This method also has a 2% to 3% error margin and is an accurate alternative to underwater weighing.

Dual energy X-ray absorptiometry (DXA) is considered the most accurate way to determine body fat (1% to 4% error margin), but the equipment is very expensive and not widely available. The usual whole-body scan requires about 5 to 20 minutes and the dose of radiation is less than a chest X-ray. This method can estimate body fat, fat-free soft tissue, and bone minerals. Thus, obesity, osteoporosis, and other health conditions can be investigated using DXA.