I searched on “jokes” and “fasting” with faint hope of finding anything. Instead I found a rich vein of Muslim cartoons centered on fasting which they do during Ramadan.
From Wikipedia: “It is the Islamic month of fasting, in which participating Muslims refrain from eating, drinking, smoking, and indulging in anything that is in excess or ill-natured; from dawn until sunset. Fasting is meant to teach the Muslim patience, modesty and spirituality. Ramadan is a time for Muslims to fast for the sake of God (Arabic: الله) and to offer more prayer than usual. During Ramadan, Muslims ask forgiveness for past sins, pray for guidance and help in refraining from everyday evils, and try to purify themselves through self-restraint and good deeds.”
Much of the humor is culturally based, referencing details of the fasting that would be very familiar to Muslims but obtuse to those not familiar with the customs. Many of them revolve around this concept, also from the Wiki: “Muslims should start observing the fasting ritual upon reaching the age of puberty, so long as they are healthy, sane and have no disabilities or illnesses. The elderly, the chronically ill, and the mentally ill are exempt from fasting, although the first two groups must endeavor to feed the poor in place of their missed fasting” and some other exemptions, like if you travel more than 40 km in a day.
Here are a few I picked out from this site: