How and When to Fast
The subject of fasting is probably least understood of all the hygienic influences and of course, very important. It forms an integral part of the hygienic system. To most people going without food is unthinkable. People usually feel unwell if they miss a meal – headaches, nausea, aches, pains, weakness – they think how could this possibly be good for me. We are going to look at this subject and examine it a little more closely and perhaps understand why it might be good.
Normally our basic currency of energy is glucose, our blood sugar. Under normal circumstances our energy will be derived from our blood sugar, but if we are fasting this is not going to last very long. In fasting we go through a number of different phases in the initial adaptation to the process.
The first phase is the gastro intestinal phase and that really means that we are living on the food we having hanging around in the gastro intestinal tract. Depending on the type of meal that we last ate that might last for several hours even 6 to 8 hours. Then we enter what might be considered the second phase. Now during that time or at the end of that time when the absorption is finished from the gastro intestinal tract, we start to get changes in the blood sugar level. Obviously when the blood sugar level starts to fall, the brain is detecting this and monitoring this and obviously is going to take some action to support this blood sugar level. So we go into the second phase of fasting which is a stage where the body becomes aware that the blood sugar level is falling and it has to enact certain processes to support that blood sugar level so we get what is called the glycolytic phase. That merely means that we have in our livers, muscles and various places in the body, a sort of a complex carbohydrate called glycogen which is a storage of glucose. So then the body starts to introduce this second phase where the body starts is breaking down the glycogen in the liver and it is converting that to sugar to support the blood sugar level which now reaches what we might refer to as a basic physiological minimum. That basic physiological minimum is extremely important. For instance if we have someone like a insulin dependent diabetic we won’t get that effect because they have a problem handling carbohydrate of course, and the blood sugar level will remain high in the case of a diabetic and in some cases may even increase. So we don’t get this drop in that situation so generally speaking we are going to approach their problem completely differently and probably not fast them.
Unfortunately we don’t have enormous reserves of glycogen so the glycogen phase is not going to last very long. So glycogen might be something like 8 to 24 hours maximum. Then we have to enter a third stage. At 8 to 24 hours the glycogen will support the blood sugar level. Now when we think of these things in vivo, in the body itself during function, there are not clear cut separate phases, they are smoothly integrated, it is a gradual process. However we get then to the 8 to 24 hours and at this stage we are getting to what is called gluconeogenesus which merely means gluco glucose, neo new, genesis source – glucose from a new source. Now what this means is that we are going to derive our glucose to maintain this blood sugar level at this basal level, from protein, essentially muscle protein. This will start fairly early, even overnight between the evening meal and the breakfast meal, break fast in the morning when we break the fast in the morning we already find amino acids building up in the blood so gluconeogenesus has already started at that time. So it might start somewhere around 12 hours on. We start to utilize muscle protein to support the blood sugar level. Now obviously as we can appreciate, it is not a good idea to be breaking down our muscle protein. Fortunately the body doesn’t break down protein indiscriminately. This is a rigidly controlled process. This is one of the wonderful things about the body the more you learn about it the more you realize how fearfully and wonderfully functional it is, the incredible intelligence that it possess in relation to performing the various processes and how so beautifully orchestrated and integrated they are. Now with the gluconeogenesus it is obviously not a good idea that we lose protein from the body so the body doesn’t continue this for very long.
Then we enter the fourth stage which is ketosis. Ketosis means that we are actually breaking down and utilizing our biggest reserve in the body and that is fat. Now even people who are thin still have several kilograms of fat in the body and of course most of us are not in that category of being thin so we may have many many kilograms of fat in the body and as fat has 9 calories per gram as opposed to protein or carbohydrate which only has 4 calories per gram it is a very rich source of energy. As you can see with this particular process of ketosis if the body can subsist on fat and at 9 calories a gram and if you are fasting and resting at only about 900 calories a day maximum, then you have only a 100 grams, less than 4 ounces, a 100 grams of fat will supply enough energy for a day, so a person can go for an extremely long period of time. In fact there are cases in the medical literature of a person who went 382 days, there are many cases of people who have gone 200 days. The longest fast I have personally seen is a 103 days. For a person to be fasting 10, 20, 30 or 40 days, that is relatively a short fast, it is nothing in comparison to the reserves of the body. Even so I have to caution people against fasting on their own without proper supervision this should not be attempted because there are processes and conditions that should be monitored during the fast.
Now ketosis means that the body actually changes, from the breakdown of fat, ketones are produced. This will happen, fat starts to build up in the blood from about 30 to 36 hours and then it will go on to the end of the fast as a gradual process. Now ketones mean that the body recognizes that ketones are a source of energy. We are maintaining a blood sugar level, this has got to be maintained, but we are consuming glucose at an enormous rate, an enormous rate, in fact if you didn’t take anything into the body at all and the body didn’t have these mechanisms you only have enough glucose circulating in your blood to last you about an hour or so. Not very long! The brain and the nervous system has an enormous demand for glucose so it is very important that the body has some other means of deriving energy in an emergency in a state where glucose is not available and this is the mechanism. So instead of using glucose the body switches to using ketones as its source of energy which are derived from fat instead of glucose which is derived from carbohydrate. We have enormous reserves of fat so the body can utilize ketones as its source of energy. The complete adaptation to utilizing ketones takes quite a while probably 10, 12 days but that is initiated from about 30 to 36 hours. Now when this takes over the gluconeogenesus is cut down as soon as the body starts to get into utilising ketones so therefore it becomes protein sparing, we spare the proteins which are involved in this.
We then get adapted to the fasting state in the first 2 or 3 days. Now people ask me the question, “what about fasting one day a week”. Well I am very much opposed to fasting one day a week because what it means is that every week you force your body to go through this business. All these adaptations and also if you are fasting just one day you are involved in this situation a lot which means you are losing protein all the time so you are never getting into the proper adapted fasting state. So I personally believe that fasting one day a week is a very bad practice. It is not good for your health and you shouldn’t do it. Aside from that, one of the basic reasons for fasting is anorexia, loss of appetitie. You go through the medical literature and you find in the major diseases, especially acute diseases, one of the first symptoms to arise is anorexia, loss of appetite the body is telling you unmistakably, I don’t want food. Don’t eat. As anorexia is the indication it is hardly likely that every Wednesday or every Monday or whatever, you are going to be anorexic.