Dry Fasting: The Science Behind This Incredible New Health Hack

Dry fasting has been breaking the internet, yet its inner workings remain a mystery to most. Well boys and girls, take out your pen and paper, this will be one heck of a science class.

Also known as an absolute fast, the results of dry fasting can be nothing short of phenomenal: weight loss of 5 pounds a day, younger, tighter skin, improved memory, diabetes prevention, cancer regression, with an endless list of miraculous benefits (and check them out here!). 

Although the practice has been around for thousands of years, it only started to make waves with the science to back up these dry fasting results finally coming to light. 

Most of the studies today are courtesy of the research done on the benefits of dry fasting during Ramadan when 1.7 billion Muslims dry fast for a month (10–22 hours depending on the region). However, Russian doctors and scientists have also been perfecting the art for almost a century. 

What Happens When You Dry Fast?

Whenever you dry fast, you stress the body. Food and water intake are vital to fuel your system’s daily processes. Without this energy source, your body shifts metabolic pathways to create fuel for itself internally, which activates a series of physiological changes that make your body a more efficient, healthier organism. 

Although you may not like stress, your body secretly does. Stress is a way of life; stress builds muscles, stress innovates, stress pushes boundaries. Stress is a powerful instigator of change, and when you push through your comfort zone, good things happen. 

Two stress factors cause the changes of dry fasting, and you’ve probably guessed them: food deprivation and water deprivation. 

Food Deprivation During Dry Fasting 

You deprive yourself of an external energy source, usually glucose (sugar), whenever you fast. For most people, glucose stores run out in about 24 hours, although that depends on body type, lifestyle, and diet. 

Once the glucose from your last meal has run out, your body taps into your second resource for energy—glycogen, from your liver. Once this glycogen has also run out, blood sugar levels and insulin levels drop. Insulin is what moves glucose into the cells for energy, so your cells are now starving. 

This drop of insulin levels sets off alarm bells to your pancreas, which now secretes glucagon to find glycogen inside your muscles. At the same time, glucagon also stimulates more growth hormone secretion, which slows down muscle tissue loss (see study).

Once the glycogen in the liver is all used up, your body finally needs to eat into its backup reserves—your fat stores. Through a process called autophagy (and more precisely lipophagy), your body starts breaking down the triglycerides in fat cells to get its new source of energy— glycerol and fatty acids. 

Both glycerol and fatty acids can be used as fuel by many of your body’s cells. However, brain cells can’t use them as energy, so your brain needs an alternate fuel, but not to worry, your system’s on top of it. 

Back in the liver, glycerol gets turned into glucose, which becomes fuel for most of the body’s cells, and fatty acids get turned into ketones to fuel your heart, muscles, and brain!

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Ketosis is a natural metabolic process that occurs when your body’s primary source of fuel shifts from glucose (from sugar) into ketones (from fat). Your liver always makes some ketones for your brain, which happens overnight, whenever you’re sleeping, which is why many fasting fans advocate skipping breakfast in their intermittent fasting window— so they get more keto time! 

Ketosis is a natural result of food deprivation because it’s an alternative fuel for the most important cells of your body when you lack food: your brain cells. 

However, dry fasting takes ketosis a level up. For most people, just getting to the threshold levels of ketosis can take 3–4 days (sometimes even weeks) if consuming less than 20–50 carbs a day, or 5–10% of their calorie needs.

Intermittent fasting speeds entry into ketosis, as you’ll be more often in ketosis, but it can still take days, and water fasting (where you don’t eat for 72 hours) can take 2–3 days to get into ketosis.

This study shows how after 3 days of starvation, your brain reaches 25% of its energy from ketones. But during long-term starvation, this study shows it gets 60% from ketones. And this is what happens with dry fasting. 

Dry fasting is a hack to ketosis. Just within 24 hours of dry fasting, you can achieve the ketosis levels of 72 hours of water fasting.

Dry Fasting Increases Ketosis 

Dry fasting increases ketosis exponentially, and the more often you dry fast, the easier you slide into ketosis. Being in ketosis enhances growth, performance, clarity, and fitness—your brain thrives on ketones.

We were all born in the state of ketosis, and breast milk is even a ketogenic food, so infants and even children are always in ketosis, as explained by this article based on a Cahill study (2006).

Ketogenesis is the process where your liver makes ketones from fatty acids in your body (or even from the fat you consume). Your body increases ketone production whenever your brain needs more fuel, and ketogenesis provides a quicker, steadier stream of energy for the brain and muscles. Your body is always making some ketones for your brain when you sleep.

That’s why intermittent fasting is also so popular, as you extend your overnight fast into lunchtime, you increase your hours in ketosis.

There are three types of ketone bodies: Beta-hydroxybutyrate (BHB), Acetoacetate, and Acetone. Acetoacetate is the predominant ketone, which becomes BHB or acetone. 

Excess acetoacetate goes out through urine (think ketone strips). Acetone is not stable and exhaled as the sometimes unpleasant ketosis breath. BHB fuels your muscles and brain stores—whenever you measure ketosis, it’s the BHB you look for. 

Ketones are an excellent food for the brain and arguably an even better energy source than glucose. Ketosis protects your brain cells because it increases the levels of BDNF or brain-derived neurotrophic factors, which is like miracle grow for your brain.

BDNF protects it and helps neurons grow. Ketones also protect the brain by reducing oxidative stress and glutamate (an excitotoxin could cause neuronal death). However, ketosis is beneficial for multiple reasons, including weight loss, cancer, epilepsy, brain injuries, Alzheimer’s, and Parkinson’s.

Being in nutritional ketosis, where the levels ketones in your blood are at least 1.5–3.0 mMol, which means your body is reaping more benefits.

Ketosis encourages metabolic processes that support full-body healing and rejuvenation, including autophagy, stem cell regeneration, and human growth hormone. 

Of course, this increased production of ketones during dry fasting is not solely because of lack of food, but rather, a cumulative effect brought on by the dual stresses of dry fasting—which includes the lack of water. 

Dry Fasting’s Water-Making Mechanism 

Water is the stuff of life. No creature on earth can survive without water (except for viruses), and a dry fast forces your body to adapt and make its own water. 

Without this ability to create our own water, humans wouldn’t be alive. Imagine if your caveman ancestors just rolled over and died when it was too cold, or too hot, or needed to hide from some beast outside their caves. Days later, when the coast was clear, they would still need to go out and hunt for food and have to be healthy and fit. Not likely to happen if we withered away after three days. 

So our bodies learn to thrive in harsh conditions, and when resources are scarce, your body shifts metabolic pathways towards making its own water. 

Your body is constantly making some water. About 400ml a day is being made through fat oxidation (which can be increased by intermittent dry fasting). However, the big triggers for water creation happen when your brain senses your body is dehydrated. 

When all glycogen in the liver and muscles are depleted, and there’s no more fuel for your cells. Your blood is thick because of the additional solids in it; the osmoreceptor in the brain triggers your pituitary gland to release ADH, an anti-diuretic hormone. 

ADH stimulates the adrenal medulla in the kidneys, and epinephrine is released. Epinephrine now induces lipolysis—or translated into English, fat-breakdown! This is induced by lipase, a hormone that eats into the triglycerides in your fat cells to make fatty acids and glycerol.

As we know, fatty acids and glycerol become glucose and ketones in the liver. But not all the fatty acids become ketones, some fatty acids circulate freely in your bloodstream and enter the cells all 37 trillion cells all over your body. 

Inside the cells’ mitochondria, your cells break down the (CO.CoA) chain of the fatty acid to get carbon, hydrogen, and Acetylene Co.A (CH3CO.CoA), which means hydrogen (H) molecules are formed in every cell, which then combines with the oxygen (O2) that you breathe and makes H20!

However, this water-making process doesn’t extend to the other unwelcome hosts inside your body, such as harmful microbes, parasites, and bad bacteria, which all depend on water. So every time you dry fast, you starve pathogens of their water supply and finish them off.

There’s also another pipeline for your body to get water—and it happens through a process called autophagy. 

Dry fasting triggers a spike in autophagy, or ‘self-eating, a metabolic recycling process that recycled unneeded cells to get more proteins that can repurpose to repair and create fresh new healthy cells. When the cells get consumed or broken down, they release water since cells are 60% water. 

According to Dr. Sergey Filonov, who has supervised thousands of dry fasts over several decades, your body can make up to 1 liter of water a day. That’s why most people feel more thirsty in the first 24 hours of dry fasting, but not so much after, as you’re getting pure metabolic water.

This 1989 study done in Malaysia during Ramadan shows how urine production and water content in your body are the same for the entire dry fasting period. 

In 2013, a pioneering 5-day dry fasting study in Germany also found that even after 5 days, none of the 10 participants showed any signs of dehydration. The study also could not explain the water loss during the dry fast and the increasing urine discharge of patients over 5 days. 

Interestingly enough, the process of autophagy, an essential factor of endogenous water creation, only surfaced in 2016, when Japanese Scientist Yoshinori Ohsumi won the Nobel prize for his research on the subject. 

Cellular Recycling Mechanisms of Dry Fasting 

The combination of the changes during dry fasting triggers a cellular recycling mechanism or internal clean-up of your entire system. The star contributors of this spring clean are AutophagyStem cell regeneration, and Human Growth Hormone. 

These processes happen during water fasting or intermittent fasting, but to a lesser degree, reach a higher peak during prolonged water fasting on day 3. Dry fasting’s harsh physiological environment amplifies these processes so you can reap benefits within a third of the time.


Autophagy is possibly the best-known benefit of dry fasting, considering the research on autophagy warranted a Nobel Prize for Medicine, which should indicate how significant this finding was for humanity. 

study done by Kuma & Mizushima speaks about autophagy as an intercellular recycling system, and autophagy is the process your body uses to clean all its in-house junk. 

Untitled design 35 e1687971127326Autophagy consumes dysfunctional, unhealthy, and damaged cells, proteins, and organelles helping your body recycle this cellular material towards new material and repairing itself. As more cells are being repaired and made, your body requires new building material. 

Autophagy is activated even after 30 mins of fasting, and continues 4 8 hours, and becomes heightened about 36 hours into fasting. The longer you spend in autophagy, the deeper the healing.

Autophagy works through a potent mechanism—every cell’s stomach or its lysosome. To imagine how lysosome works, think of your cell as a house, and the lysosome is the washing machine, except this is no ordinary washing machine; this is a magical washing machine. 

This washing doesn’t just clean all the dirty, worn-out old clothes you hate; it also recycles them into pretty new clothes you want to use. If you have a damaging red wine spillage, or your mother buys you a fashion abomination, you chuck it into the washing machine, and presto, and it breaks the material down to its bare threads, and ta-dah it comes back out as a new leather skirt. 

That’s what happens in the cell—all the sickly, non-functional organelles, ribosomes, mitochondria, folded proteins, or dangerous pathogens get thrown into the washing ‘lysosome’ machine. Lysosomes have over 50 hydrolytic enzymes.

All at 5.0pH, super acidic that can dissolve almost anything, and good thing too—otherwise, all these troublesome materials will start piling up in your house, making it messy and chaotic. Once the lysosome has recycled old material into new material, you can use them for cellular repair and new parts (see this study).

Lysosomes are also the stomach of the cells, so they consume proteins needed for the cells, recycles them into new protein parts, and then release them back out into the cell to make new cellular parts. Lysosomes can be in any size to swallow up even small viruses or big bacterias — and if you dry fast long enough, over 3 days or so, you’ll manage to destroy almost all types of bacterial and viral infections. 

There are three main types of autophagy: 

  • Macroautophagy—a large vesicle (autophagosome) captures old organelles like mitochondria, merges with a lysosome, and gets recycled. 
  • Microautophagy—something outside the cell wall is captured and combined with a lysosome to be processed or recycled. 
  • Chaperone-mediated-autophagy (CMA)—damaged proteins get targeted to be destroyed or processed by the lysosome. 

Dry fasting’s unique feature is that it specifically increases CMA, which hunts down these ‘bad’ or sick cells that can come from scar tissue, skin tags, old, saggy skin, cysts, tumors, folded proteins, and malfunctioning cells, like cancer cells. CMA targets bacteria, parasites, and viruses— anything that does not serve a useful purpose to your body gets broken down to be used as building material for cellular recycling. 

Autophagy helps make you younger and healthier simply by removing all the pathogens, poisons, and toxins that age you. 

Specifically, during dry fasting, the destruction of these pathogenic cells through autophagy releases more toxins into your system, making the blood ten times more toxic than before, killing even more pathogens because they cannot survive in the harsh environment.

Autophagy is a self-preservation mechanism that helps humanity survive harsh conditions and is a cellular reset for your body. It also supports stem cell regeneration and proliferation and helps treat neurodegenerative diseases like Parkinson’s, Alzheimer’s, and cancer — as this study suggests.

Human Growth Hormone 

Human Growth Hormone (HGH) is the hormone that keeps you young, fit, and youthful. It’s often called the elixir of youth—and the reason athletes look young for their age, as exercise increases HGH. It makes you more alert and focused, gives you quality sleep, improves circulation, preserves muscle mass, and stops fat cells from accumulating. 

This study describes how just 24 hours of water fasting increases HGH secretion by 2–3 times. In a dry fast, the levels of human growth hormone (HGH), 5 times that of water fasting. HGH helps preserve muscle mass, reduces fat tissue accumulation, and even increases muscle mass during dry fasting.

Increased HGH, amplified by Ghrelin (the hunger hormone), triggers noradrenaline (norepinephrine). All these increase your fat-burn, and metabolism. 

During a dry fast, where only the necessary will survive, every cell in the body creates its internal furnace to burn toxins and create more fuel, raising the temperature of your body, which means more energy is needed to destabilize yourself. This study on fasting indicates that even after 4 days, the body is using 10% more energy than before it started. 

Stem Cell Regeneration 

Autophagy recycling mechanism during dry fasting also consumes unhealthy white blood cells, and now your white blood cells get broken down, dropping their numbers drastically. 

This depletion of white blood cells induces the reduction of the enzyme PKA in your system. PKA is the gene key that inhibits stem cell renewal and pluripotency: the ability for one cell to become many cells, so this shutting down PKA in your body cues stem cells to start proliferating like crazy. 

This study done on mice and human stem cells shows that prolonged water fasting of 2–4 days, enables stem cells to regenerate and develop into multiple types of new cells for your body.

Conducted by the University of California in 2014, it’s the first evidence of how fasting triggers stem-cell regeneration and creates an entirely new immune system for chemotherapy patients.

Autophagy eats up inefficient cells, leaving vacant space and more material for plenty of stem cells to take up the space. You had plenty of stem cells when you were young, but stem cells reproduce in the body but age as you age, becoming less effective and potent with each new generation.

Dry fasting restarts that machine, degrading poorly stem cells, and revitalizing and proliferating new stem cells.


The science behind dry fasting shows just how magnificent and capable the body is to heal. As more studies and data surface, it’s becoming more evident that the body is fully capable of fixing itself.

If you’re interested in dry fasting for age reversal (and weight loss), check out my video course, 25 Again! The Dry Fasting Lifestyle For A Younger, Slimmer You

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***Disclaimer: I am not a doctor/ physician, and although I have a bachelor’s degree in Biomedical Science, I cannot and do not hold myself to be a medical professional (“Medical Provider”). This article does not contain medical /health advice. The medical/ health information here is for general and educational purposes only. It is my opinion, based on my research and personal experience, and not a substitute for professional advice by your health care provider. Please consult with a professional before acting on the information here, and do not disregard medical advice or delay seeking medical attention because of anything you read in this article. THE USE OR RELIANCE OF ANY OF THE INFORMATION ON THIS WEBSITE IS SOLELY AT YOUR OWN RISK.***


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