Long-time readers of the Living Intentionally blog know that I am a big fan of fasting. Regular fasting beautifully complements a healthful diet that is rich in healthful fats, adequate in protein and low in non-vegetable carbohydrates and grains.
I think fasting is an essential aspect in realizing and maintaining excellent health. It doesn’t need to be anything difficult, either. Generally speaking, intermittent fasting is enough to gain significant advantages. Whereas traditional fasting will have one forgoing food for 24 hours or more, intermittent fasting typically has one restricting food intake to a particular window of time every day. For me, for example, I typically only eat one or two meals between the hours of noon and 6 p.m. on any given day. The rest of the time, I limit my intake to fluids.
Longer, more traditional fasting has its place, too. Fasting for 48-to-96 hours has a dramatic effect with regard to the recycling of dead and damaged cells. During such prolonged fasting, damaged white blood cells are recycled to provide the body with necessary scavenged proteins. When the fasting has ended, the damaged immune system cells are replaced with healthy cells once again. The result is improved immune health and increased overall well-being.
Fasting is an important element in maintaining a fat-burning metabolism. Most people eat far too much with far too much regularity, which means that we never get our bodies into a state of even temporary starvation. Our biology is based on cycles of feast and famine. When we’re in a constant state of feast, the body’s maintenance schedules are interrupted, causing us to age prematurely.
Otherwise healthy people who experience low blood sugar when they don’t eat are experiencing symptoms of a metabolism that has been trained to derive its energy almost entirely from glucose. In essence, the body might know how to store excess energy as fat, but it has almost forgotten how to use fat as a source of energy. Intermittent fasting is a great way to train the body to derive its energy from fat stores.
During prolonged fasting, the body enters a state known as ketosis. When your body has become well accustomed to dealing with the feast/famine cycle, your brain shifts from primarily using glucose for energy and relying more on ketones. Ketones are an energy source derived from fat-based metabolism.
Your body’s muscles, including your heart, operate extremely well with ketones as a fuel source thanks to having an enzyme that enables them to convert ketones to glycogen. Your brain prefers glucose as a fuel because it is missing the enzyme that your muscles employ, but here your liver helps out. When your blood sugar drops and ketones become elevated, your brain signals to your liver to produce a ketone-like substance called beta-hydroxybutyrate. Your brain is able to use this compound as fuel quite efficiently with practice.
With practice is an important point here. The body absolutely thrives on the feast/famine cycle. Regular fasting promotes a number of processes within the body that stimulates protein reclamation, dead-/damaged cell recycling and helps to reduce inflammation.
Extreme fasting, e.g., longer than 3~4 days, should be avoided at all costs. Extreme fasting stresses the body beyond healthful norms and puts it squarely into the realm of survival mode. Beyond approximately 3 days of fasting, the body loses its ability to produce fuel for the brain. To compensate for the lack of brain food, which is essential for staying alive, the body breaks down its own muscle tissue to provide the necessary proteins for fuel synthesis. This has highly destructive side effects and should be avoided. I recommend, and personally practice, restricting fasting to a maximum of 3 days.
Fasting has numerous health benefits when done with care and not to extremes. The more regularly you limit your intake, the more you’ll find your hunger cravings diminishing. Regular fasters know well that our sense of hunger largely goes away as we have trained our body to derive its energy primarily from fat-based metabolism.