It is one of my very rare spiritual posts, but you can ignore that if you are concerned with the material side of things. The fact is though... "A common scenario is for someone to break the fast after a few days due to the pressures of life, and then binge on comfort food"
I suspect you will be doing that too, unless you change your lifestyle to prepare for the fast.
Weights are in kilograms, multiply by 2.2 for pounds. Good luck, and if the first fast doesn't work out, don't give up, come back here and keep trying. Oh and you drink water only on a water fast.