Updated 3/24/2024
No food or drink
When fasting in the Bible is mentioned, it means to fast from both food and water
(Esther 4:16; Jonah/Yonah 3:7). It is the Hebrew word, tsom ( צום ), pronounced like "zoom" or "toom/tomb"
(modern Hebrew uses the "zoom" pronunciation). So when fasts are called for with some of God's holidays, like
Purim and
Yom Kippur, I always fast from both food and water, as well as avoid baths and showers since soaking in water re-hydrates you.
Note: Modern Jews often refer to fasting as ta'anit ( תענית ) or taynis, which are not Hebrew words found in scripture. They appear in the Jewish Halacha or oral traditions, which is not scripture.
Because all consumption is avoided with fasting, this includes the taking of pills, supplements, or other medicine with water or food, so if you need to take medication, you may choose to drink minimally to take the medication or avoid fasting altogether. If you have health concerns, consult your doctor about fasting.
No sexual activity
You should also keep from all sexual activity during fasting. This is not spelled out in scripture but is an implied part of fasting, as sex and bodily pleasures are obviously not in line with mourning or afflicting oneself with fasting. Keeping from sex is also a part of consecration or dedication to God (Exodus/Shemot 19:15), so having sex makes people soiled spiritually as far as preparing for a sacred dedication to God. That is a different motive than abstaining from sex with fasting, which is meant to afflict oneself and show self-control.
What is allowed during fasting?
Yeshua (Jesus) said, "When you fast, anoint your head [rub oil in your hair] and wash your face, so that your fasting will not be noticed by people but by your Father who is in secret, and your Father who sees what is done in secret will reward you" (Matthew 6:17-18). So general hygiene and grooming, like washing your face, brushing teeth, shaving, lip balm, modest use of skin lotion, grooming your hair and using hair styling gels, oils, etc. is fine. Using makeup is ok, but really is not in the spirit of fasting, which is to mourn or to petition God with suffering.
Note that when Christ spoke in Matthew 6 about fasting, He was talking about not appearing excessively afflicted as hypocritical, over-religious people do, especially Jewish leaders, who had no real remorse or heart to fast and used it to appear more pious to gain honor from the public (Matthew 6:16), so do not use fasting in inappropriate ways but simply to mourn, to help petition God with prayer, and to honor the traditions of God's holidays.
What to expect
When fasting, you will become
dehydrated which can give people headaches. Also expect to have less
energy so do not plan strenuous work or exercise during fasting. You may
become dizzy from light activity after fasting through a day. No more than 3 days and 3 nights of fasting (72 hours) is recommended. Fasting longer than that can lead to organ failure and other health problems that could require medical treatment, so only fast longer than that if you are spiritually mature and led by God to do it.
When coming out of a fast, you may have stomach upsets so immediately eating or drinking acidic foods (citrus fruit, high vinegar content, sour foods), spicy foods, tough meat, hard crunchy foods, or harder to digest foods may give you stomach issues. The longer you fast, the more likely stomach upset will be a problem, so
a 24 hour fast (one day and one night) should give minimal problems. Your mouth and throat will be very dry, too, so drink plenty of water or fluids before and with your first meal. The roof of your mouth may get sore because of eating hard foods before your mouth is re-hydrated, so your first meal should be soft, like soup or porridge, and of course, not too hot or spicy.
