Body compostion measurement spec - https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.body_composition_measurement.xml
Example of FFM calculation - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4608267/
Body compostion measurement spec - https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.body_composition_measurement.xml
Example of FFM calculation - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4608267/