The saints take fasting period as a very important period based on its biblical history and meaning, but today many people or Christians fail to fast due to the health implications involved.We all know well that our body relies on the nutrients taken as food materials among others. One of the most important nutrients required by the body on a daily basis is sugar. Sugar is the source of energy generation in the body.But if cells use up the sugar in blood circulation, the body will always resort to other sources of energy in the body. It is also important to understand that the body has reserve stores for unused sugar. When you take in a lot of food, some unused glucose will be stored in the liver inform of glycogen. Other sources of glucose store is in muscles and fats.During periods of fasting or lack of food intake, the body resorts to the stored glucose inform of glycogen.Glycogen is broken down to glucose that body cells use to produce energy for their ongoing activities.What happens when the stored glucose is finished? It usually takes a minimum of 24 hours for the reserve glucose to be finished up. When the stored glucose has been used up by the body cells, the body will turn to fat reserves as a source of energy. This also means that people with less fat are likely to starve or get affected by fasting than people with high fat weight.The main problem here is that both brain cells and red blood cells cannot depend on the source of energy from fatty acids. However, at this stage, the body will resort to amino acids from muscle tissues as a source of energy.We possibly see people who change feeding pattern or do not feed regularly tend to lose weight even though they are a live. One of their main constraints actually is glucose deficiency.Another important factor to mention is that our body has got a physiological mechanism to control all problems that can be brought about by glucose depletion.After the glycogen stored in the liver is finished, your liver will start to make ketones as one of final products of fat metabolism. Once ketones have been formed in the required amount, the brain cells will start to use ketones as a source of energy. Again, this is why a situation is where one lacks food or fasting is able to carry out his daily activities normally.However, the red blood cells that are main moderators of transport in blood do not use ketones but instead will use glucose from muscular breakdown.This means you will not meet some one anemic or with blood-related problems because they are fasting.During manufacture of glucose from muscular breakdown, the rate at which the muscular components are catabolised will be such that your muscles are spared as much as possible.But one of the tangible health benefits that have been seen in fasting people is the possibility of increased toxin elimination from the body.This is because most of the toxins in the body are stored at fat reserves and partly explains the link between overweight and diabetes.The longer you fast, the more body fats are burnt and the more is toxins elimination from the body system. One important idea to put in mind is that your body will not jump at glucose from fats until the stored glucose in the liver is finished. The glucose in your liver will get used up usually after one day of fast, but for some individuals, it can take up to 36 hours. After this period, the body resorts to stored glucose in muscles and fat tissues. People, who would wish to increase their toxins elimination, usually take less food. This is because as you decrease the burden on your digestive tract coupled with adequate resting potential, then you increase the rate of toxins elimination by the liver. Most of the toxins from the digestive system are eliminated by the liver.In our medical profession, we tend to control the gastro-intestinal toxins to patients with liver disease. This has also been the basis of alcohol restriction to patients with varying hepatic problems.    Dr Joseph Kamugisha is a resident oncologist in Jerusalem, Israel