Final answer:
The authorized method for estimating body fat content accurately is Dual-energy X-ray absorptiometry (DEXA), alongside other methods like skin-fold calipers, BIA, and hydrostatic weighing.
Step-by-step explanation:
When estimating body fat, one authorized method is the use of Dual-energy X-ray absorptiometry (DEXA). This technique uses two low-dose X-ray beams that pass through the body. The differing amounts of energy absorbed by bone, lean tissue, and fat tissue are calculated using standard mathematical formulas, allowing for a highly accurate estimation of fat content.
Additional methods include skin-fold measurements using calipers, Bioelectric Impedance Analysis (BIA), and hydrostatic weighing. Each of these methods has its own level of accuracy, cost, and technical complexity.