There are hundreds of scientific and independent studies on the practice of fasting as a way of healing the body and as a way to fight off illness and other degenerative diseases. It is also one of the oldest, and therefore longest-running healing modalities on earth. Fasting is getting a lot of attention lately as doctors, scientists and nutritionists alike are speaking up about the incredible results they have seen from fasting with their client and patients. Myself included.

A fast is a period of time where the body stops eating, in other words, the body stops receiving nutrients from food consumption. A fast can be anything from 16 hours to-21 days. A person can fast on one specific food type or liquid or a combination or simply water intake. Mostly, fasting refers to 100% liquid intake.

Eating requires a lot from our bodies, the entire process of digestion from start to finish is extremely detailed including various organs, thousands of processes and responses. Fasting provides a period of physiological rest during which time the body can devote all self-healing mechanisms to repairing and strengthening biological functions and damaged organs.

Our bodies need energy to function. We make this energy from the foods we eat. When we deprive our body of its main fuel source, it must find a way to make energy. Fortunately, our bodies have plenty of internal energy stores, our fat.


The main form of energy in the average human diet is from carbohydrates. When we eat anything that has natural sugars (fructose or glucose) or carbohydrates, our body uses this for fuel. It’s a little like using cheap petrol to run your car. Works, fine, cheap and easy to find.

When we eat carbohydrates, (all fruits, bread, noodles, grains, cereals etc.) our body turns them into glycogen and stores it in the liver. The liver will hold around 100 grams of glycogen stores to be used up as fuel. If we do not top up with carbohydrates, the glycogen stores become depleted, which typically takes 16-24 hours. Once there are no more carbohydrates from food consumption or subsequently no more glycogen, the body switches from glycolysis to ketosis.


Ketosis is the name of the process of the body using ketones (or ketone bodies) for energy. Ketones come from our fat cells, those internal energy stores I mentioned. After the glycogen is used up, your body starts burning stored fats, which are converted to ketone bodies, (acidic chemicals) used by neurons as energy. So to simplify, burning fat creates ketone bodies which creates energy. Take away carbs, and the body kicks into a kind of a starvation mode, tapping into fat stores and releasing ketone bodies produced by the liver. FYI: ‘Nutritional Ketosis; is when the aim of diet is to boost ketosis, this is done with a diet made up of high amounts of fats, medium intake of protein and low intake of carbohydrates.

If you eat three meals a day with snacks between, your body doesn’t have the chance to deplete the glycogen stores in your liver, and the ketones aren’t produced. For the purpose of detox, either in a concentrated format like this one or simply for encouraging good long term detox, there is a huge benefit in pushing the body to make ketone bodies since we are storing most of our non-water soluble toxins along with heavy metals in our fat cells.


The word ‘autophagy’ is derived from the Greek words “auto” (meaning self) and “phagy” (meaning eating). “Self-eating” So in other words, autophagy is the process of our own cells eating themselves into oblivion. More accurately, – the decomposition of damaged old or aged cells.

Even in healthy people, cells are continually becoming damaged as part of the normal metabolic process. Factors such as age, stress and exposure to free radicals increase the rate at which or cells become damaged making it vital that we can eliminate damaged cells. Damaged cells that serve no purpose can linger inside the tissues and organs. Damages cells within our body can trigger inflammation pathways and are often markers and contributors to various diseases which is why boosting autophagy is so important.

Nutrient deprivation is the key activator of autophagy, Fasting provides the greatest known boost to autophagy. Ketosis is also considered an important indicator of autophagy. Research suggests the strongest effects of autophagy occur between the first 48 hours after glycogen depletion.

There is a balance here too of course. You can become unwell from accelerated autophagy as well as too little. There is a natural cycle to life, especially from an evolutionary biology perspective which is ‘feast and fast’ or ‘feast and famine’. We repair and grow new cells from the powerful nutrients we eat and then switch into cellular repair as we fast.


Fasting periods boosted ketone bodies and speeds up fat metabolism.
Fasting normalizes our metabolic hormones like insulin, leptin and ghrelin.
When we eat, insulin goes up, simple as that. When we fast, insulin drops and blood-sugar levels get the chance to stabilize
Fasting promotes autophagy, i.e. the process in which our body destroys damaged or dead cells, which in turn aids the regeneration of new cells and hence promotes the anti-ageing process.
Fasting can help resets your Circadian Rhythm and improve sleep quality. It is very helpful not to be digesting food when the body is trying to sleep.
Intestinal cells have been studied and have shown that a 24-hour fast could improve cellular performance and may help people bounce back quicker from infections or serious illness. (“Starve a cold”)


Think back to the last time you ate a huge meal (Christmas for example) or just completely overdid it. Did you feel more energetic and mentally alert? Or did you feel sleepy and a little dopey? When we overeat, blood is sent to your digestive system to cope with the huge influx of food, leaving less blood going to the brain resulting in a “food coma”.

When we humans were hunter-gatherers, for more than fifty thousand years or so, before the industrial revolution, we functioned exactly this way; feast and famine. When there is no food, the body switches into hunter-mode, needing all its faculties to hunt and kill animals and forage edible plants in lush forests. From an evolutionary perspective, it makes sense your brain should be functioning well when you haven’t been able to obtain food for a while. Many believe this is why neuron growth and cognition is boosted during a fast.

Now to the present day, neuroscientists have uncovered more information about the brain in the last 20 years than in the past 2000 years. We are only just now understanding that we have grossly underestimated the function, ability and potential our brains process.

Mark Mattson is the current Chief of the Laboratory of Neuroscience at the National Institute on Aging. He is also a professor of Neuroscience at The Johns Hopkins and is the source of much of the following information since he is spearheading the research. I have also seen in myself and in my clients over and over again the incredible ways in which fasting affects mental clarity, lateral thinking, memory, focus and positivity.

Fasting does good things for the brain, and this is evident by all of the beneficial neurochemical changes that happen in the brain when we fast. It improves cognitive function and stress resistance, increases neurotrophic factors, and reduces inflammation.


Fasting is a challenge to your brain, and your brain responds to that challenge by adapting the stress response pathways that help your brain COPE WITH STRESS.

The same changes that occur in the brain during fasting mimic the changes that occur with regular exercise — both increase the production of protein in the brain (neurotrophic factors), which in turn promotes the growth of neurons, the connection between neurons, and the strength of synapses. (THE WIRES FIRE BETTER) Some more of Mark Mattson findings on fasting and brain function:

  • Fasting can stimulate the production of NEW nerve cells from stem cells in the hippocampus⠀
  • Fasting increases the number of mitochondria in nerve cells, improving learning and memory ability⠀
  • Fasting enhances the ability of nerve cells to repair DNA ⠀
  • Also interesting to know that ketones promote positive changes in the structure of synapses important for learning, memory, and overall brain health.