A few years ago i had a naturopath test me with a vega machine .
It was quite simple i held onto a little metal cylinder with my left hand and the naturopath gently touched my other hand between my knuckles with a metal probe.
The wires from the probe a d cylinder fed into a laptop computer and the naturopath went through a long list of common food groups from a to z .
I was then given a color print out outlining certain foods I do not digest well like chicken and whole wheat bread and quite a few types if rice .
I was able to eat turkey, beef, pork a d all kinds of vegetables etc..
Anyway I thought ok I will give it a try.
To my surprise I went from 195 pounds to 175 pounds in 2 weeks , so I'am a believer !
I hope that answer's your question.