If I had a body mass of 56 kg how would I get an estimate of my total body weight? I need a full calculation and what the method is called. Also, I have read that D2O IS used in some experiments to calculate tbw in kgs. Can you explain this process fully to me?

The article I have read is ‘Rapid measurement of deuterium content of breath following oral ingestion to determine body water’ Simon Davis. Physiol meas 22 651-659.