How did they test it? If they used the bio-impedance thingy (where you grab the handles) that does nothing but fuck with your mind.
The only real test is to kill you and rip off all of your body fat and weigh it. Everything else is a SWAG. Don't fret so much. Do you really care that some weenie at a gym told you that you lost 5lbs of muscle when your lifts are going up, you can see your abs and everyone is noticing that you look great? Prioritize my man, prioritize.
People too weak to follow their own dreams will always try to discourage others.