“A healthy person can survive without food for 50–75 days”
J. Carlson, Professor of Physiology, University of Chicago.
Studies have demonstrated the tremendous beneficial effects of fasting on the various human body functions, particularly on the gastrointestinal (digestive) and cardiovascular (heart) systems. Fasting does not affect the working of the brain because mental work does not require extra energy. Your brain consumes equal amounts of glucose and oxygen whether you are awake, asleep, eating or fasting. Here is a very basic overview of what happens when you fast.
After your cells have used up all the available fuel in the bloodstream, your body turns to your liver and your muscles, where sugar is stored as glycogen. You start lipolysis, which is the body burning through your glycogen reserves to make glucose. This usually takes 16–24 hours.
When your body has no more glycogen to burn, it turns to autolysis (self-digestion), which is when the body starts eating old and diseased, dying, decaying or dead cells, for energy. Gluconeogenesis (GNG) also starts, which is when the body converts and recycles the old proteins to glycogen, for energy. Gluconeogenesis is a natural liver process in humans and animals and can happen during fasting or intense exercise.
Ketosis/Ketogenesis kicks in, which is when the liver breaks down body fat stores into ketones, to be used by the brain, red blood cells, heart and muscles. This happens when there are no carbohydrates supplied through diet and helps to preserve the body’s protein stores. Ketogenesis is a very natural metabolic adaptation process, otherwise known as ‘muscle sparing’. You lose less than 200 grams of muscle per day once full ketogenesis is reached (usually by the third day of water fasting), but this varies enormously depending on how much body fat you are carrying. If you are generally healthy this small muscle loss is negligible.
As fat is increasingly burned as fuel, fat-stored toxins are released into the bloodstream to be metabolised by the liver and kidneys, and to be processed as waste. Ketones are very acidic but, during RIF®, the blood is far more alkaline and the blood can buffer this acidity to keep the blood pH healthy. Too much accumulated ketones in the blood and you have ketogenesis. The natural sugars in juice fasting usually prevent ketogenesis.
Day 4 onwards
Your stomach shrinks and your appetite drops. This is where juice fasting becomes fun as a glass of juice is as filling as a big dinner. You also start to experience increased energy levels and a heightened sense of awareness and clarity of mind. Keep your teeth brushed as ketogenesis can be smelly!
**PLEASE NOTE: For those who are brand new to fasting and are a little unsure, please read my ‘Fasting: WARNING‘ article before you try fasting.
Jason wishes to deeply thank, acknowledge and recognise the effort and contribution that the PIF Foundation has provided on a voluntary basis since 2014, as we educated, motivated and inspired change that helps transform the health, vitality and longevity of people all over the world.