Your weight decreases because you shit yourself when you die and the liquid in your body evaporates. Wolf, i know how much you LOVE fake science, but get your head out your ass. All your posts are the same, something which isn't the case is somehow true because you heard about a study. There is no soul. It is possible NEAR DEATH experience have induced people into premature releases of the chemical DMT which is found in all humans at the moment of birth and death. When ingested it can cause you to experience a bright light sensation and extremely hard to explain hallucinations. These people are just tripping. Don't romanticize death so much, we aren't primitive man.
To say there may be a soul or a god is fine, its comforting, but to assert that any of this can be proven with science is malarkey.