You mean fasting.
Fasting is an excellent spiritual discipline as it decreases the neurotransmitters necessary for suppression of our own personal unresolved issues and thus they come to the surface for soul cleansing. It's the flip side of emotional eaters syndrome and is due to 90% of the body's serotonin being produced in the enterochromaffin cells in the lining of the stomach and upper GI.
The pathway to knowing and experiencing God is both logical and scientific. A miracle is merely science that we don't understand. That does not take away from their reality.