In The Urantia Book, physical fasting is viewed as a practice of the old order and is not part of the new gospel, as it can be dangerous and lead to a loss of desire for food and spiritual focus. However, spiritual fasting, when done with a pure heart, can be a temporary and justified practice for those who have lost their spiritual teacher to seek God's guidance and grow in righteousness. It should not be a showy ritual, but rather a secret, loving exchange between the individual and God to deepen spiritual connection, not to gain spiritual gifts.
Nothing that I will say should be construed as a disagreement. When I share something intimate like silent fasting I would want to get feedback. It is not silent anymore anyway.
I have fasted for health reasons to regain a improved balance of my metabolism. As a side-effect I noticed that after a day or so I gained some mental clarity. I also found that it was vital to drink pure water, because when fasting your body mobilizes stored fat and initiates autophagy. This releases toxins that were stored in fat tissue. Pure water helps flush these metabolic waste products through your kidneys without adding contaminants. Your kidneys will thank you. The body is an electrochemical instrument and it will keep on working even when you do no eat.
I can not say that I grew in righteousness, but I certainly achieved a level of calmness and receptivity, because I set time aside for my fasting.
Since every body has a different metabolism no advice on the length of a fast should be given I always looked at it as an experiment.
The God of my understanding does not want me to suffer, nor do my Spirit Parents love me any better than they love any other of their sheer infinite amount of children. As you correctly observed, you can engage in fasting in the hope to become more open for spirit contact, as God is infinitely patient and waits for us to open to His guidance. Towards Light and Life, Oliver
The purpose of fasting is to turn away from worldly things like oppression and vanity and instead focus one's heart on God, leading to a deeper connection with the divine.
Godspeed.