For best results light the lighter at "once lit" then size it up while you say "lighter indeed" if or not you can tell then light whatever your lighting during "the lighter the lighter the lighter I be"
I recommend a jovial mood during this incantation as if excited to be thinner.
This leans on old magic and Germanic ontology so feel free to use it in public, witnesses are a good thing.
Keep any lighter used in this way out of rituals and don't use a lighter you have used in rituals for this purpose, again old magic.
Stop using if you have less then a eighth inch of fat left
Consult a Temple Employed Jewish Orthodox Demonologist (schooled professional) if in rare cases, bleeding of the eyes, nose, ears, hands, urethra or **** occurs. If you find yourself blurting or having ticks. Hear voices were you previously did not. Have an unusual increases in appetite or libido. Or if you experience night terror/sleep paralysis. As you may be having a bad natural reaction or more likely mixed this magic with literally any other kind.
I have not mathed or tested this incantation. I do however endorse its effectiveness but at 6' 2" and 300lbs id like to lose 50/100lbs and I'm sure its a bit too potent for my needs. All that said if you need to make weight for a prize fight it would do that just the equations about your bloodlines and who was there to see it with their bloodlines and how good you are at that general thing. Suffice to say if its just you and you don't usually overcast just see how it goes over a couple weeks after the first try.