eli5 how can a bathroom scale determine the body fat, water content and “dry” bone mass just from passing some electrical current?

Question

eli5 how can a bathroom scale determine the body fat, water content and “dry” bone mass just from passing some electrical current?

In: 796

Answer 1

I had one that clearly just estimated based on height and weight.

(We tested it with different people with vsibly different muscle mass. It also changed depending on what gender you told it you were)