This is an awesome way to measure the BMI.
The BMI is an attempt to quantify the amount of tissue mass (muscle, fat, and bone) in a person.
This then helps to categorize that person as
- underweight
- normal weight
- overweight
- obese
based on that value.
The data is saved only on the device and nowhere else. You can also have a look at the data of all the previous times you check your BMI. Cool way to keep track of your BMI :)