It is interesting.
Are the grains digested?
Flour, especially refined flour, is digested before it reaches the intestines. On the other hand, whole grains, containing various fiber fractions, reach the very end of our digestive tract, supplying beneficial intestinal bacteria.
The digestive cycle, its dynamics is coupled with the daily cycle, as well as phenomena related to sleep, brain work, etc.
People with vitamin deficiencies or liver damage experience severe pain, especially with heavy foods or recently genetically modified soybeans, and often the pain disappears when the light comes on.