Sunday October 18, was an unusual day in many respects, not least of which it had been declared a day of national fasting and prayer.
It was not without controversy not only among politicians and non-Christians, but surprisely among Christians as well.
There was the argument that national imprudence was being reneged to God in an attempt to bolster a failing popularity.
While other quarters felt it wasa mark of national humility to call for corporate prayer and subjugation to God.
The process of implementation proved controversial too.
Was it to be by legal compulsion, public coercion or by personal conviction?
The arguments were sometimes heated with bibles being slammed on tables.
Whatever your beliefs the date was fixed and the event took a national character. There was a lingering questions, which though unaddressed, was casting some doubt on the safety of the process for all.
Those who were bolder, asked the question directly, “Is it safe for me to fast?” In many churches the matter was addressed in the more subtle way the announcements were made by the church leaders……. “Let us all participate in the national day of prayer if our health permits us to”. The questions around fasting and health have been questions which have exercised the minds of experts for years.
Who can fast safely? Can children fast, can pregnant women fast, and can old people fast?
Most importantly can I fast? In order to get a better understanding of fasting and its effect on health, I thought it would be prudent to discuss the question of fasting and health.

•What is fasting?
Fasting can be defined as the deprivation of food for religious, political or personal reasons. The history of fasting is unclear, but it appears to predate many of the modern religions. It was practiced in the ancient Greek civilisation as a way of maintaining personal purity, with the belief that bad spirits (demons) could enter the body through food.
In modern times most fasting is conducted among religious groups, particularly among Muslims, the Greek Orthodox Churches and some protestant churches.
Fasting has also been used for political reasons, and in the process of liberation struggles, widely popularised by Mahatma Gandhi in India. It is well known that the first President of Zambia, practiced religious and political fasting frequently.
Broadly speaking there are two types of fasts.
There is the Absolute fasts, in which both food and water are not taken at all and secondly  a limited fast, in which water is permitted.
The human body appears to have adapted itself to periods of plenty and periods of little. This may be related to the history of mankind, where there are periods of good harvest and periods of poor harvests.
The human body expects these periods in the life of an individual, so it has naturally developed three types of reserve for these eventualities. These are emergency reserves, short term reserves and long term reserves.
Not unlike many modern day countries which have food security policies to ensure sustenance of their nations and populations.The body has anFRA(Food Reserve agency), that buys the maize from the farmers and stores it in reserve.
Just like the currency of the country Zambia, is kwacha, the currency of the body is sugar(glucose).The body judges the state of  nutrition (wealth) of the body by the level of  sugar in circulation. When the sugar is high it begins to store.
The emergency store storage silos, are in the liver. The liver store the sugar in the form of larger sugar molecule called Glycogen. When the emergency reserves are full, it them stores the food in the form of fat under the skin and around the organs wherever there is space, as short term reserves.
The long term storage areas or strategic reserves (the stores of last resort), which should hardly ever be used, except in dire situations are the protein store, in the muscles and bones. This way the body which normally gets energy for the body by burning sugar, in normal situations, will switch to burning fat in starvation or fasting situations. This understanding, by the way, is the basis for some of the famous dieting techniques, like the famous Atkins diet.
When you cut down on eating carbohydrates and sugars, the body is tricked into thinking that the body is starving and begins to break down fat, leading to weight loss.
•How does the body respond to fasting?
People generally eat about three times a day, this is the normal reserve period for the stomach. So supplies run out every six to eight hours.
When the stomach empties after 6 to 8hours and no more food is coming along it rings the emergency reserves to kick in. The chemical that controls sugar levels called insulin, will begin to fall.
When insulin falls the Liver is triggered to release emergency reserves. So the large molecule of  Glycogen (50kg bag), begins to be broken down into glucose (Pamela 5kg packs) for immediate use as energy source for the body.
This  is something most people will have experienced, where you were feeling really hungry a minute ago, then suddenly from no where you feel fine again. It’s the liver that has kicked in and released its reserve to tidy you over.
These reserves re limited, so after two days they run out, if no food is forth coming. After 48 hours the body mobilises the intermediate stores, it begins to break down fats, converting some to sugar and using some of the fatty acids directly for energy.If all the fat in the body is used up, which may take anywhere from five to 15 days, the body will turn to the strategic reserves. The stored proteins in the muscles and bones. When you hear of people lost at sea, or lost in the high mountains or prisoners on hunger strike for prolonged periods then they are probably using the reserves in the muscle and bone.
This is the cause, of the profound diminution in size, built and bulk that is sometimes seen in people who have been on hunger strike, and sometimes in patients with severe chronic ill health. The response of the body is similar it mobilises all reserves to keep the person alive.
This description only relates to food, the human body cannot last for more than a few days without water. It has no strategic reserves for water.
•Who can fast and is it healthy to fast?
If the consequences of fasting are well understood, based on the previous explanations, then it may be easier to understand the possible exemptions to fasting.
The person best suited to undertake a fast is a person who is generally healthy in all respects.
The fast presents a significant stress on the body, which the body can handle, quiet well if no other health stress exists.
To put it simply, a growing child, may suffer severe consequences from a prolonged fast or starvation process. This is because a child has limited reserves, because he or she is using what the body eats to enable the body itself to grow and develop. For this reason, most children are quiet thin especially below about 10 years old.
So many religious fasts exclude children below 18 years old. When growth and development is complete, then fasting is safe. In pregnant women, who are undertaking a process of growth and development of a growing baby, the body reserves are committed.
Therefore, the stress of a prolonged fast  may jeopardise the health of their growing baby. For the elderly especially after the age of 65 years, the natural body reserves undergo a programmed shrinkage.
This means though they will be able to fast, they will not be able to mobilise their emergency reserves, as well or as easily. In states of ill health it is unwise to fast.
Chronic  diseases, such as Diabetes, Kidney, Heart and Liver disease will not respond well to a fast.
In particular in Diabetes, the idea is to maintain a constant level of sugar in the blood which will be easy to control. Fasting presents a major disturbance to sugar control in Diabetes and should be avoided by diabetics.
Many people believe that they can lose weight by fasting. This has been proven inaccurate, because though weight loss does occur, it is not sustainable.
The weight gain that follows the weight loss often leads to significant weight gain. The question still remains, next time there is national call for prayer and fasting, can I fast?
The answer is if you are a healthy person between 18 and 65 years, you can fast and probably should do so occasionally, it is likely to improve your general health and delay aging.