Who says the metabolism is slower after the fast? The body will absorb nutrients it has depleted while fasting but if you feed it natural foods and you are overweight to begin with there will not be very much of this and you will very likely continue to lose weight while refeeding.
And my experience of fasting to lose weight is very positive. The main thing to remember is to break your fast naturally and not overeat, if you can manage that then fasting is the best preparation for more fasting.