Dry fasting is intense and scary. People worry about dying from dehydration. This is the main fear of anyone looking into dry fasting. Let's take water fasters as an example. Water fasters have built a worldview of surviving for long periods of time on just water. They know the feeling of being shunned by the rest of the world and being viewed as crazy. So it gets pretty funny when you have water fasters calling dry fasters crazy. The first step on this crazy journey is to understand that you won't die in 3 days if you stop drinking water. At least the vast majority of the world's population won't. I never like making blanket statements, and I believe most people understand the concept of nuance. If you're not suffering some sort of disease that may impair lipolysis or other factors that are critical to dry fasting, if you don't have contraindicated illnesses, and if you're not running a marathon in the Gobi desert, then you're a pretty solid candidate.
Water availability is essential for fasting birds to maintain their fat stores and the team says, ‘We revise currently established views [that protein catabolism is the main source of metabolic water] and propose fat serves as the primary source for metabolic water production’. - by Kathryn Knight
Why is a 3-day dry fast safe?
So why won't we die in 3 days without water? Well, it's quite simple. Our body creates its own water. This is known as metabolic water or endogenous water production. Not only do we have built-in capabilities for making our own water, but we also have internal cellular mechanisms, autophagy, and molecules like osmolytes to protect us from stressors associated with dehydration. It's really cool and I'll touch on them a little bit, but I highly recommend you read more of my articles about osmolytes and hypertonic/hyperosmotic stress to get a better understanding.
- Osmolytes become one of the pillars of support during this process, so I highly recommend reading my osmolyte protocol on the dry fasting club website.
Structured EZ Water
On top of all of this, it would make sense to dive into structured water, something that occurs during dry fasting and is linked to cellular health. We restructure our water when we dry fast, and we create our own structured water. Imagine all the savings when you don't have to spend money on deuterium-depleted water, hydrogen water, and all other water ionization and zeta potential-related tools.
Studies suggest that not just adding osmolytes, but also creating a state of hyperosmolarity (similar to dehydration) inside cells, could be beneficial. This state is thought to remove disorganized water from cells and encourage the absorption of osmolytes. This change could help restore normal cell functions, especially in cancer cells. The idea is to shift from disorganized to organized water inside the cell. This shift might bring back a balanced and orderly state in the cell's energy system.
How the water is created and how much?
When we fast, our body turns to stored fat for energy, a process known as fat oxidation. This isn't just about energy; it's also about water production. The chemical equation for fat oxidation can provide some insights.
Let's take a common fatty acid found in the body, palmitic acid (C16H32O2). When oxidized, it combines with oxygen (O2) to produce carbon dioxide (CO2), water (H2O), and energy. The equation looks something like this:
We can simplify this with a Generalized fat oxidation reaction: Fat+O2→CO2+H2O
Taking approximations and averages into consideration for the human body, it looks like 1 gram of fat would convert to approximately 1.12 grams of water. If you wanted to create a more balanced range then we'd be looking at something like 1.07-1.14 grams of water.
Now let's move on to the study I wanted to discuss.
Zebra finch study on metabolic water production
I love the title of this article from 2016. "Zebra finches can drink water from their own fat". I couldn't have come up with a better one myself. Granted, I understand that we are not zebra finches and that human physiology can differ significantly. However, to assume that we don't share some similarities in how our cells metabolize fat is silly. I mean, you listen and take into consideration studies that are mostly based on rats, mice, and worms when it comes to longevity and fasting, so excuse me for bringing zebra finches into the conversation ;)
Birds and humans are part of the animal kingdom, which means we share a common ancestor. Our lipolysis mechanisms are similar and are regulated by the same hormones. For example, adrenaline and glucagon promote fat catabolism in both birds and humans. Both humans and birds store fat as a source of energy. Both use lipase to break down fats into fatty acids and glycerol, so it means that fat metabolic pathways must have been conserved to some degree across both species for millions of years.
So what does the study show?
Well, the conclusion of the study indicates that in the case of zebra finches, fat is the tool the body uses to create water in situations of water deprivation (aka dehydration). Let's dive into the study to see what insights we can pull out when it comes to dry fasting.
How was the experiment set up?
It's quite beautiful how the researchers approached this. I absolutely love the fact that they experimented for dry fasting conditions, and at such exquisite detail.
The researchers also accounted for light exposure, 12 hours of daylight, and 12 hours of lights off, and kept the laboratory at a consistent temperature of 30±1°C (thermoneutral conditions for zebra finches). This is great because the scientific community is finally becoming more and more aware of the reason why testing for light conditions is very important in animal experiments. Things like circadian rhythm influence, behavioral impact (think mood, foraging, and mating behavior), and different wavelengths of light (can stimulate different vitamin synthesis and even the immune system) all play a big factor. It's also important to mimic natural environments as best as possible when doing animal studies, and that includes light exposure.
They also prepared the zebra finches for the study by doing brief stints of both food and water deprivation as well as capturing them and putting them into cages for brief durations. Essentially, they made sure that the experiment didn't incorporate a sort of stress-shock response to the sudden change in conditions. This is great because we know that the human body is resilient, but that it requires gradual changes to adapt efficiently. If we undergo aggressive acute stress, we may get quick detrimental effects, for example, if we drastically induce hypertonic stress like in dry fasting, we could be in a lot of trouble, but because the body gradually dehydrates over many days, it's able to incorporate mechanisms to buffer it and stay safe. In this same way, I am very grateful for the cautious preparatory steps the researchers took in this.
Let's summarize the following setup steps that were taken during the experiment:
- Dividing the birds into Groups: The birds were split into three groups: one group had normal food and water, the second group had only water, and the third group had neither food nor water for a day.
- Checking their Weight and Health: The next day, the researchers checked the birds' weight and measured their metabolism (how fast their body uses energy) in a special chamber. They also took blood samples before the birds were humanely euthanized.
- Looking at their Organs: The birds' organs were weighed, and dried, and the fat content was measured to see how much of each they had at the end of the experiment.
- Calculating their Energy and Water expenditure: By looking at the fat and protein in the organs, the researchers figured out how much water and energy the birds used, specifically when they were fasted in both water and dry conditions.
What were the results of dry fasting vs water fasting on the birds?
This was an excellent experiment, you can really start to appreciate the incredible complexity of science and the human ability to try to make sense of the real world. I find it so refreshing to view the power of humanity as you find pockets of specialized research. The ability of a human being to specialize in something is what allows us to progress. Piecing everything together is where the magic happens, and I'm well aware that AI will make some mind-boggling advancements in this space very very soon (it's probably already doing so).
This is my attempt at charting the information to be a little clearer and to include percentage changes to paint a better picture.
Let's summarize the results of the experiment
It becomes quite clear when you look at the data, especially after I organized it into tables comparing the different groups, that dry fasting is intense. I added a column to the data myself that specifically focuses on the relative increase or decrease compared to water fasting. It paints a picture of what you can expect when deciding which fasting to do. These birds were fasted for a total of 24 hours.
Weight loss and water content:
The body mass of birds changed significantly depending on the type of fast. Birds that were dry fasting lost around 6% weight, while the water fasting group lost about 2.5%. This indicates that in terms of weight loss, dry fasting is making the scale drop faster. Of course, a lot of this is water weight, so the loss is not strictly fat, but this is an important metric to be aware of. Because we see that the body water content remained consistent across all groups, it goes to show that metabolic water creation was keeping up with body demands. I think it's safe to say that zebra finches have an exceptionally efficient fat-to-water conversion going on.
The study wasn't formulated to see how much weight and how quickly it was regained, so this information does not give us a lot of information other than there are more intense mechanisms at play for the dry fasting birds. We know this from dry fasting experiences where people experience dramatic weight loss as the body dumps water and starts to burn fat very quickly even after just 24 hours. If you can harness the cortisol situation correctly, you can create a very powerful 36-hour dry fasting weight loss protocol. Cortisol in this case stimulates the glucocorticoid receptors in the body, especially in the abdomen, so if the refeed is done incorrectly you can expect a very fast bounce back in weight.
It's amazing how much more fat was lost in the dry fasting group. 26.9% more fat lost?!?!?!?! It's even crazier because if we simply looked at it in relative terms to water fasting, in 24 hours dry fasting burns about 20X the amount of fat. In fact, the water-fasting group barely had any fat loss whatsoever over 24 hours. This goes to show that glycogen depletion is occurring in both groups and the body hasn't tapped into deep ketosis, yet the dry fasting group is still losing fat at a high pace. This goes to show that ketosis can occur from both dehydration and from calorie restriction. This is further corroborated by many other studies like the one that shows that Hyperosmotic Stress Induces Unconventional Autophagy Independent of the Ulk1 Complex, or when I previously discussed the autophagy levels in dry fasting groups vs water fasting in The Science behind how 1 day of dry fasting is equivalent to 3 days of water fasting in raw autophagic power.
Isn't this interesting? Both fasting groups (with and without water) showed a similar decline in lean mass, indicating that the lack of water did not cause a higher breakdown of protein. Even though you lose more fat, you still lose the same amount of protein! It's like in my video about dry fasting and weight loss where I say that even though dry fasting is the world's most powerful healing tool, it is also a fantastic tool for weight loss. If you were to take someone wanting to lose X amount of fat, they would need to perform 2-3x longer water fasting than dry fasting. This would mean that they would essentially lose 2-3x more muscle mass. Dry fasting, if done correctly, is showing itself to be a hack for cutting weight even in the body-building world while maintaining more muscle. Granted, you need fat to do this safely, but there are many caveats to this, such as requiring a lower BMI to get into deeper healing.
Metabolic Water and Energy Expenditure:
Energy used is much higher in the dry fasting group. In fact, it's almost 4X higher. This shows that the body is supplying an extra amount of energy that is coming from burning the fat for water stability. We can see that there is almost a doubling in metabolic water being produced in the dry fasting group compared to the water fasting one. The extra metabolic water comes exclusively from fat deposits. The extra energy is coming from fat. This is one of the main reasons why people on a dry fast report feeling overall better and having more energy. If you go deeper on a dry fast you also start to experience something called the dry fasting "heat". It almost feels like you're on fire even though your body temperature remains pretty consistent. In ancient cultures, they called this the masculine Yang energy. It's nice to have a study show this phenomenon through data.
The Basal Metabolic Rate goes down the most with dry fasting. This relates to the concept that dry fasting is the one true 'complete fast'. And with that, it allows the body to shut down the digestive system faster. This should always be the goal of fasting. You want to give your body complete rest. What we see is that it correlates to BMR dropping faster. This is also why a dry fast is more dangerous than a water fast when it comes to refeeding. You are dealing with a digestive system that needs to carefully be brought back to life. I always find myself repeating myself. The refeed is critical. Even if you think you're young and fit and that your dry fast was only 1-2 days, you should still follow some basic principles with the refeed. This means coming out of it with water first, then some sort of low-carb broth that doesn't spike your insulin and blood sugar, followed by slowly moving up the digestibility scale. I guess I'd be remiss if I didn't add in another little tidbit of information, especially as it relates to metabolic rate. If your metabolic rate drops, the same amount of food that would have previously been digested and used up quicker, will now cause extra weight gain. I'm not going too deep into the cortisol explanation, but it should suffice to say that this is one of the reasons why you should gradually introduce food, and that includes smaller meal sizes initially. Don't let the animalistic urge to pig out win after a dry fast. Find your middle ground between satiety, stable blood sugar, and meal sizes.
Findings on Metabolic Water Production:
- Contrary to previous assumptions that protein catabolism sustains water balance, this study shows that fat is the primary source of metabolic water production during fasting, without the need for elevated energy expenditure.
- Birds with access to water managed to maintain their fat reserves better than those without water. The study suggests that water helps to conserve fat reserves, which is crucial for survival in dry conditions.
- Explanation as to why dry fasting is more efficient at burning fat faster.
My dry fasting survival adaptation theory:
My view on health and dry fasting can be summed up in this theory.
To be optimally healthy we need to cycle fat gain into fat loss, through dry fasting, to enhance the body's resilience and stem cell regeneration, and to get rid of stagnant water and senescent cells.
Throughout human history, our bodies have been shaped by the challenges of survival, from enduring injuries and illnesses to escaping threats like lions, wolves, and bears. This probably involved navigating through periods of scarce resources such as food and water. Imagine being sick and trying to ride out the sickness. Going outside delirious and weak would have been a death sentence. Having a mechanism that fed off of our fat and healed us at the same time would have been a necessity for survival. Our ancestors also had to travel a lot, often running from danger or searching for more hospitable environments. This meant that water may not have always been available. Picture a desert-style drought. This demanding lifestyle wasn't just about surviving; it was about adapting. As a result, humans had to evolve sophisticated systems designed to not only keep us alive but to ensure we thrive under such stressors (in fact many animals did). This evolutionary legacy has equipped us with mechanisms like fat storage, and a biological ability to provide energy during times when food and water are not readily available.
Fat serves as a life vest for our bodies, similar to a rain barrel ready for times of drought. It's a reserve of energy and resources, meant to be tapped into when necessary. However, modern lifestyles have drastically changed our interaction with these natural cycles. Nowadays it's common to have people who snack constantly throughout the day and have never experienced hunger. In fact, there are people who have never done a day of fasting in their life, and even those who wake up in the middle of the night for a quick snack!!! In a world where food is often plentiful and physical threats are nearly gone, the metaphorical rain barrel can become neglected. Without periods of 'drought' to use up these reserves, the stored fat can become like stagnant water: murky, nasty, and bad for our health. Unused, the fat reserves can lead to various metabolic issues, mirroring the way stagnant water attracts mosquitoes and becomes unpleasant. This stagnation is opposite to our evolutionary conditioning, which requires proper cycling of fat through different seasons. It's quite common sense to imagine humans cycling through fat accumulation throughout the summer and especially in the fall, followed by losing it over the winter. That definitely doesn't happen now, and I'm glad it doesn't, but let's remember that this type of cycle is a co-evolution and we have the ability to harness it in a safer and more beneficial way through fasting.
By dry fasting, we could mimic the natural challenges our bodies are designed to face, promoting processes like autophagy (the body's way of cleaning out damaged cells to regenerate newer, healthier cells) and stem cell regeneration. These processes are crucial for maintaining metabolic flexibility, depleting deuterium (a heavier form of hydrogen that can affect cellular processes when accumulated), and ensuring the structured water within our cells is refreshed and rejuvenated. I do think it's important to remember that there is such a thing as over-fasting and our ancestors didn't have the opportunity to control for it. But we do. The proposition that dry fasting could extend lifespan by a lot is fascinating and seems very likely.