Tag: Body density

Archimedes' principle, a foundational law of physics, provides the scientific basis for how water displacement method is used to measure body fat. This technique, known as hydrostatic weighing, relies on the fact that fat mass and lean mass have different densities, causing a person's weight to change in a predictable way when submerged in water. By comparing a person's weight on land versus underwater, specialists can precisely calculate their body density and, from there, their body fat percentage.

A pound is a pound, whether it's feathers or bricks, so it's a common misconception that one is heavier than the other. So, to set the record straight, 5 pounds of fat and 5 pounds of muscle weigh exactly the same. The real difference lies not in weight but in density, volume, and metabolic function, which has significant implications for body composition and overall health.