Final answer:
Body fat can be estimated through various methods like BMI, BIA, and DEXA, with each having its limitations and accuracies. BIA and DEXA are more technologically advanced and precise compared to BMI, while skin fold measurements provide a simpler assessment option. True measurement of body fat, however, is only possible during an autopsy.
Step-by-step explanation:
Estimating body fat content involves various methods, such as body mass index (BMI), skin fold measurements, bioelectrical impedance analysis (BIA), and dual-energy X-ray absorptiometry (DEXA).
BMI is a basic measurement using height and weight, but it alone does not accurately represent body fat content and distribution, which are crucial when assessing health risks. It can both underestimate and overestimate body fat compared to muscle mass.
BIA estimates body fat by passing a small electric current through the body and measuring the rate at which it travels, as fat impedes electricity more than other body components.
DEXA is another, more accurate method, which uses two low-dose X-ray beams to estimate based on how much energy is absorbed by bone, lean tissue, and fat mass. Visceral fat, measured using a tape measure around the waist, is especially important as an indicator of disease risk.
The skin-fold test, while simple, also provides a fairly accurate measure of body fat. It uses calipers to measure the thickness of skin at various parts of the body, comparing the results to standards based on age and sex. Nevertheless, the only way to measure body fat with complete certainty is during an autopsy.