Yes, I have done several fasts. I usually fast from something directly related to what I’m hoping to achieve.
Did I get the results I wanted? Well, generally yes. But, I should preface that by saying that I rarely fast for something very specific like a healing from a particular ailment. Usually, I’m fasting for something more general like increase in a particular virtue.
As has been mentioned above, prayer and fasting doesn’t work like magic. You have to turn towards God and submit yourself to his will.