The word fast is derived from the Anglo-Saxon faest, which means “firm” or “fixed”. Fasting is the body’s physiological rest. It’s an ancient healing practice, which is abstinence from food.
Fasting can be done for many reasons, such as health, spiritual, or religious purposes. There are various forms of fasting, including intermittent (time restricted eating, for example only eating during a 10 to 12 hour window each day), and 24 hours or prolonged fasting, which can take 3 or more days. This allows the body’s self healing properties to work, and may be reflected in positive changes in blood pressure and circulation, pulse, weight, and also in the normalization of important biomarkers such as blood glucose, cholesterol, triglycerides, liver enzymes, and many other positive changes.
Health is the normal state of any organism, and it’s the normal response to the care that we give our body — including our food, thoughts, rest, exercise, and so on. Fasting has numerous health benefits for the body, however when we do it for too long, or not properly understand the consequences, it can be dangerous too.
When we fast for longer periods of time, the body changes its fuel source from carbohydrate (sugar) to fat. This process is called ketosis, and refers to a group of chemicals (acetone, acetoacetate, and beta-hydroxybutyrate). Whatever action occurs in the body, that action is performed in the body, which is why only the body can heal itself. Fasting is a process, it is not a cure or treatment. Healing is a biological process, so there is really no such a thing as chemical drugs to heal, or a healing agent. The body heals itself.
Fasting is not starving the body. In his book, “The Science and Fine Art of Fasting”, Herbert M. Shelton explains that ”starvation results from food denied, either by accident or design to a system clamoring for sustenance. Fasting consists of intentional abstinence from food by a system suffering from disease and non-desirous of sustenance until rested, cleansed, and ready for the labor of digestion.”
Our immune system defects are at the center of aging and a range of diseases. Rejuvenate means to restore to youth and acquire renewed vitality — physical, mental, and spiritual. Rejuvenation does not mean turning back the clock, instead it emphasizes the removal of some of the negative effects of our poor living habits that have accumulated over time, and have had an adverse effect upon our health and life. It is very important that we make a distinction between time, and things that take place in time. Actions take place between entities, but neither time nor age is an entity. For example, if water constantly drops on a stone, it will wear away even the hardest stone, if continued for a long enough period. But it is the water dropping on the stone that wears it away, not simply the passing of time. Similarly, old age is really not a time of life, but a condition of the body. It is not time that produces the changes in the body that we call aging, these changes are due to other causes. The diseases of old age are the effects of the way that we have treated our body throughout our life.
Fasting, or energy restriction, is associated with health improvements and increased longevity, improved autophagy, modification of apoptosis, and alteration in hormonal balance. It is simply the body cleansing and restoring itself.
Fasting for a short period, such as 24 hours, will not give body enough rest and repair time. During this short time, blood glucose levels drop and carbohydrate (sugar) and proteins will deplete. But if you were then to continue the fast, adaptation will occur, and the body will start the utilization of ketones derived from fat. Once this is established, the fast will continue with the body’s major source of energy coming from fat, rather than protein. During these adaptations we may lose protein, until we reach the properly adapted fasting state.
An appreciation of the physiology of fasting is essential to the understanding of therapeutic dietary interventions, and the effect of food deprivation on various diseases. Prolonged fasting is an important aspect of nutrition providing total physiological and mental rest, which allows the body to make radical biochemical changes that are an important first step in improving health. Fasting needs to be performed correctly, so please do not attempt prolonged fasting without supervision.
I think for all of us, the quality of our life is more important than just the length of our life? Periodically, or even just occasionally, a fast will help rejuvenate your health. You just need to pay attention and listen to what your body is telling you.