Which method measures body density through body volume calculation?

Hydrostatic weighing is a method that measures body density through body volume calculation. This technique involves submerging a person in water to determine their body volume based on the water displacement. The principle behind this method is Archimedes’ principle, which states that an object submerged in a fluid experiences a buoyant force equal to the weight of the fluid displaced. By measuring both the person's weight in air and the weight while submerged, one can calculate body density using the formula:

Body Density = Weight in Air / (Weight in Air - Weight in Water)

This calculation provides a precise estimate of body density, which is an essential component in assessing body composition, as it allows for the differentiation between lean mass and body fat.

In contrast, methods such as air displacement plethysmography, DEXA, and skinfold measurements do not directly calculate body density through volume displacement in water. Air displacement plethysmography uses changes in air pressure in a closed chamber, DEXA employs dual-energy X-ray absorptiometry to measure bone mineral density and soft tissue composition, and skinfold measurements rely on calipers to estimate subcutaneous fat thickness. Thus, while all these methods assess body composition in some form, hydrostatic weighing is uniquely associated with direct