I have fasted in the past, finding it a very useful tool for purging my body, clearing my mind and regaining focus on the things that matter. After a fast, I am more aware of what I put into my body and of the signals my body gives me. After a fast, I take better care of myself. My girlfriend hates it when I fast, and not just because I'm a little bit cranky the first day. She thinks it's unhealthy to go without food, but regulars fasts have actually been proven to be very healthy, if you do it right. There is a method to fasting, and it depends greatly on the length of the fast.
One day fasts -- A one day fast is an easy, useful, tool which can consist of one or more skipped meals or simply not eating all day. The only intake should be water or herbal teas. Most people will be able to get through it without problems but if you suffer from diabetes, some forms of migraine or even asthma, not eating is probably not a good idea. An option is to avoid solid food but drink fruit shakes, where fruit is mixed 50/50 with water. After the day of fasting, start with light, easily digestible foods the next day but don't be afraid to eat regularly after your first meal.
Two or three day fasts -- From personal experience, day one is the worst. You're hungry, cranky and your head hurts. After that, the hunger sensation fades away and by day three it's actually not that hard to get through. It's absolutely possible to get through two or three days fasts on water only. If not, use the fruit shakes. Remember, you're supposed to feel tired and in a bit of discomfort. After you stop or break your fast, it's advisable to start with a boiled down barley solution the ancient Greeks called kykeon (κυκεών). The thick gruel is fine. Be careful with your food in the day following the fast, but you can eat regularly the day after.
Four day fasts or longer -- Realistically, your body can handle a fruit juice fast for a good few days. A week is not out of the question, although you may want to consult a doctor on it first. Don't try it with a water-only diet; our bodies aren't used to it anymore and going over the three-day limit should be worked up to. After three days, the body is at the lowest point. It's then that a process called ketosis sets in and the body turns on itself for fuel. This is where the purification starts. On the first day after a prolonged juice fast, drink only the strained barley water. On the second day, a thin, soupy gruel is best, and on the third day, you can eat a thicker gruel. On the fourth day, you can cook in lentils and vegetables as well, and on the fifth day, you can go back to your normal diet. Don't go back to regular food right away, because you'll nullify your hard work.
Like I mentioned, fasting does not feel good. You're hungry, low on energy and if you're like me, your mood will plummet with your blood sugar level. Still, fasts were used in ancient Hellas--and all over the world in modern times--to cure an assortment of illnesses. Anything from arthritis to flue, to metabolic and gestational problems, can be treated with a good fast. Why? Because a fast cleans up the toxins in our organs and blood. It's a natural purge. This is the reason why animals stop eating when they are sick; they rely on their body to get rid of that which ails them. Hippocrates describes it as such:
"Everyone has a physician inside him or her; we just have to help it in its work. The natural healing force within each one of us is the greatest force in getting well. Our food should be our medicine. Our medicine should be our food. But to eat when you are sick is to feed your sickness."
Great thinkers like Hippocrates, Plato and most of their students were avid practitioners and promoters of medicinal fasts and felt that a fast helped them think clearer. They found that the Inner Physician--as they called the mechanism--worked from top to bottom, starting at the head.
Head / Brain: headaches, dizziness, vertigo, wooziness, lightheadedness
Nose, Sinuses: sneezing, runny nose, itching, stinging, post nasal drip
Throat: soreness or constriction, hoarseness, scratchiness
Lungs: chest congestion, wheezing, phlegm discharges, foul breath odors
Skin: rashes, acne, pustules; excessive or abnormal sweating; strange body odors
Stomach: sour or nervous stomach, stomach cramping, belching, bad breath
Liver: sore eyes, bitter taste in mouth, sallow complexion, pain or distension under the ribs on the right side
Gall Bladder: colic, spasm, tenderness or pain underneath the liver area
Intestines: foul smelling gas, cramping, diarrhea, spastic colon or irritable bowel
Kidneys: low back pain and weakness, fatigue; frequent urination, often urgent; strongly colored or smelling urine
Now, none of this sounds very appealing, I get that, but the body undergoes these effects because of the pent up toxins in our system, not because it's struggling with the lack of food; mammals are incredibly capable of dealing with a lack of nutrients.
It should be noted, though, that our bodies have grown unaccustomed to being without anything. We overfeed it, often with a lot of junk, and listen to its every single signal of want. The people who lived in ancient Hellas--and also before that--were used to going without. Not only did they fast regularly for religious and medicinal purposes, but the amount of food there was to go around relied upon the Gods. In a bad year, there simply wasn't enough food to quench every hunger. For the ancient Hellenes, a one day fast was peanuts, while I'm writing this with a growling tummy and a huge need to go to bed.
Fasting is a beautiful practice and I feel it should be a regular part of the Hellenic Tradition, but it's important to listen to your body before even attempting it. A short fast should only be done when your body needs it or, in this case, when your body is in a good enough shape to do it for a religious festival. If not, cheat a little and use the fruit shakes. If that's also too much, pick something else you love to go without; if you smoke, vow to go without cigarettes for the day, if you're a big coffee drinker, give it up for the duration of your 'fast'.
Longer fasts should only be attempted when the temperature is not to hot or too cold; climate control within the body takes a lot of effort and will make fasting infinitely harder. Fasting is a practice that's reserved for healthy adults and non-pregnant women. It's not suitable for children, the elderly, pregnant women or anyone with medical or psychological conditions which may be triggered by a lack of food. If you're struggling with eating disorders or anything else that may be triggered by a fast, pick something that does not involve food or drink, like electronic devices. Go through the day without using a cell phone, your computer, the radio or the T.V.. Especially in a religious setting, it's the 'going without' part that matters most.
I'll get through my fast just fine, including making dinner for my girlfriend tonight. I've done it before and it's never a problem. I like the hunger I feel and the amount of willpower it takes not to nibble on the leftover cheesecake in the fridge. It helps to bring me closer to my religion, the ancient Hellenes and myself. Tomorrow, I get to celebrate and eat that cheesecake, but today, I grieve with Demeter over the loss of Her daughter and I remember a time when people went without food because Demeter had not shared Her secrets yet. Today, I sit on that hill, surrounded by women, and am brought closer to my Gods and my community by the hunger we share. Today, I fast, out of love, and gratitude.