Fasting vs ProLon from a Biophysics Perspective

A Broader Perspective on Fasting

Fasting is one of the most powerful cleanup tools for metabolic and cellular health. However, its benefits are not solely dependent on food absence; they are amplified by aligning with metabolic function and supporting the body’s ability to utilize energy sources beyond food. The state of the body’s metabolic function, ability to use fat, lactate and glycerol as fuel particularly at a mitochondrial level, determines the efficiency of fasting and the prevention of muscle loss.

Metabolically flexible individuals, particularly those adapted to fat-burning (ketosis), can fast with lower risk of significant muscle loss because their mitochondria are more efficiently adapted to oxidize fatty acids and ketones for energy. Compare this to those who are predominantly glucose-dominant burners who have less metabolic flexibility and will likely reach gluconeogenesis (breaking down muscle proteins for glucose) faster. That being said BMI does come into play because if a sedentary overweight individual with a fatty liver undertakes a fast, they will also be able to last a longer time before they begin metabolizing muscle to replenish glucose. So there are several factors involved to consider. 

Fasting, Ketosis, Glucose Needs, and Muscle – The purpose of Fasting is repair and renewal followed by feeding and building

Blood glucose is tiny and precious, held within a narrow range of about 65 to 100 milligrams per deciliter even in deep ketosis. At any given time, the human body contains only about four grams of circulating glucose, barely a teaspoon. Yet this small pool is fiercely protected because certain tissues, such as red blood cells, portions of the brain, and parts of the kidney, depend entirely on glucose to function.

When carbohydrate intake stops, the body must maintain this delicate balance through remarkable adaptive systems. Within roughly twenty-four hours of fasting, the liver’s glycogen stores are mostly depleted. At that point, the body pivots toward gluconeogenesis, the creation of new glucose from non-carbohydrate sources. Two primary substrates, lactate and glycerol, take center stage, allowing the body to preserve blood sugar without dismantling its muscle tissue.

Lactate, produced when muscles metabolize small amounts of glucose during activity, is shuttled through the bloodstream to the liver. There, it enters the Cori cycle, where it is converted back into glucose using energy derived from fat oxidation. This elegant recycling loop provides a steady glucose supply for essential tissues while sparing amino acids from being stripped from muscle.

Simultaneously, the breakdown of body fat, known as lipolysis, releases glycerol from the triglyceride molecules stored in adipose tissue. The liver transforms glycerol into glycerol-3-phosphate and then into glucose through enzyme-driven pathways. This process becomes especially significant after the first day of fasting, when most glycogen is gone, and glycerol may provide up to one fifth of total glucose production. In this way, fat stores do more than provide energy—they directly help maintain the brain’s minimal glucose requirements.

During this transition, ketone production from fatty acids rises sharply. As ketones accumulate, they replace glucose as a major fuel for the brain, dramatically reducing the body’s need for glucose and slowing the breakdown of amino acids. The hormonal environment shifts to reinforce this protection: insulin and IGF-1 decline, glucagon and norepinephrine rise, and growth hormone secretion increases. Growth hormone in this context is not a muscle-building signal but a protein-sparing one, it helps preserve lean tissue by promoting fat mobilization and reducing proteolysis.

In a water fast, true muscle growth cannot occur because the body lacks both amino acid substrate and the activation of mTOR, the molecular pathway that drives muscle protein synthesis. However, fasting is not inherently catabolic. It is better described as a protective and reparative state, one in which hormonal balance and mitochondrial signaling favor maintenance, repair, and metabolic recalibration.

The mitochondria themselves shift behavior during fasting. They rely more heavily on fatty acid β-oxidation and ketone metabolism, which increase the NAD⁺/NADH ratio, reduce oxidative stress, and stimulate autophagy and mitochondrial quality control. In this sense, fasting is a repair phase, a biological pause in which the body cleans, recycles, and strengthens the cellular machinery that underpins metabolism.

Recent high-quality research confirms that water fasting induces a far deeper metabolic shift than fasting-mimicking diets such as ProLon. Within hours, the body transitions from glucose dependence to fatty acid and ketone utilization, marked by a reduced respiratory exchange ratio, greater mitochondrial efficiency, and a rise in the NAD⁺/NADH ratio, all of which enhance redox balance and mitochondrial biogenesis. This shift not only optimizes fat oxidation but also strengthens cellular energy production and resilience. Studies show that autophagy is significantly more pronounced during water fasting, with stronger inhibition of mTOR and upregulation of protective stress response genes compared to calorie-restricted fasting-mimicking protocols. Elevated ketone bodies act as metabolic signals that suppress muscle proteolysis by reducing the demand for gluconeogenesis, helping preserve lean tissue even during prolonged fasts. These effects are amplified in individuals with good leptin sensitivity and metabolic flexibility, where fasting further restores hormonal balance and improves mitochondrial function. While fasting-mimicking diets offer some benefits for stem cell renewal and metabolic health, their impact on autophagy, fat oxidation, and mitochondrial renewal remains consistently lower than that achieved through true fasting.

Over time, the body learns to fuel itself with extraordinary precision. Fat stores provide both the energy and carbon skeletons needed to sustain glucose production. Muscles provide recyclable lactate rather than structural protein. The liver and kidneys power gluconeogenesis through fat-derived energy, while ketones protect the nervous system and spare muscle from degradation.

Because muscle gain requires nutrient abundance, building is the natural counterpart to fasting’s repair phase. The best way to preserve lean mass through fasting is to enter it with strong metabolic flexibility, stay lightly active to preserve neuromuscular signaling, maintain hydration and electrolytes, and refeed intelligently with high-quality protein and resistance training afterward. This refeed period activates mTOR, restores glycogen, and allows the body to rebuild on the foundation of renewed cellular integrity.

In short, fasting is not a period of deprivation, it is an ancient rhythm of renewal. The body’s systems are designed to defend its glucose pool, protect its muscle, and optimize its mitochondria through cycles of depletion and restoration. When paired with intelligent refeeding, fasting and recovery become the twin forces of human metabolic balance.

For people who struggle with water fasting (drinking just water and not consuming food), ProLon fasts can be a great strategy because everything is set out when to eat and drink and it maintains the minimal glucose stores to prevent any risk of gluconeogenesis. There will still be an initial craving for protein but it’s a way to still keep autophagy going for longer wile still consuming some glucose. ProLon can be a useful bridge for glucose-dependent individuals to transition into ketosis, mimicking some of the benefits of fasting while reducing energy stress, however it’s a bridge, not a longevity strategy. Proper water fasting is still the optimal goal for autophagy when cycled with feeding and muscle building post fast.

Fasting for 48 to 72 hours is a good strategy for well-nourished individuals who are reasonably insulin and leptin sensitive to improve their health further without putting too much stress on the body. For 5–7-day fasts, it’s advisable to prepare metabolically beforehand and undertake it in an environment limiting other stressors such as indoor living, non-native EMFs or pollution/mold just to name a few. 

True fasting offers unparalleled biophysical benefits, particularly when the body is metabolically prepared and supported by key environmental and physiological factors. These include minimizing exposure to artificial visible and non-visible light, maintaining adequate mineral intake, having sufficient melanin pigmentation on biological surfaces (eyes, skin, and hair), and being cold adapted. External energy inputs such as full-spectrum natural light, grounding, fresh oxygen enriched with negative ions, and deuterium-depleted water further enhance the process. Together, these tools amplify mitochondrial function, optimize energy availability, and prevent muscle wastage during extended fasting.

Bust muscle wastage is the least of your concern when undertaking an extended fast when metabolically prepared, it’s muscle deconditioning and neuromuscular activation deficits resulting in reduced strength and coordination that you should be more concerned about. Movement during fasting is thus still very important, when in evolutionary history did humans fast and not move very much unless they were extremely ill. It was the fasting individual that got up and continued to hunt or gather who eventually found food and survived.

1. True Fasting vs. Fasting-Mimicking Diets (ProLon)

ProLon, as a fasting-mimicking diet (FMD), offers a practical alternative for those not yet metabolically prepared for extended water fasting. By providing minimal calories, ProLon stimulates autophagy and reduces insulin signaling, though it may dilute the hormetic stress required for deeper repair and regeneration. ProLon can help glucose-dominant individuals transition toward ketosis and fat-adaptation, supporting a more natural metabolic state in the long run. ProLon is a protocol which allows carb addicted individuals with a suboptimal metabolism to still fast and receive some benefits. From a biophysics perspective it’s much wiser to upgrade your metabolism and mitochondrial function and then undertake a true fast and experience true longevity.

2. Muscle Mass and Fasting: The Role of Mitochondrial Function

Muscle wastage during fasting occurs primarily when the body lacks the ability to efficiently oxidize fat or ketones. In individuals with poor mitochondrial function (e.g., glucose-burning dominance), the body compensates by breaking down muscle protein for gluconeogenesis.

However, fat-adapted individuals experience significantly less muscle loss, as their mitochondria efficiently use fatty acids and ketones for energy. Ketones (like beta-hydroxybutyrate) directly spare muscle protein by reducing the need for gluconeogenesis and have an anti-catabolic effect. This is all built into evolutionary biology because food was much more scares in the wintertime than the summer and foods available in winter are more fat and protein dominant compared to in summertime where carbs reign supreme.

Muscle integrity during fasting hinges on the body's bioenergetic support and its interaction with the environment. Consider the following processes:

• Full-Spectrum Light and Muscle Bioenergetics:
  Infrared and red wavelengths penetrate deeply into tissues, stimulating mitochondria within muscle cells by activating cytochrome c oxidase in the electron transport chain. These wavelengths also structure water within cells, enhancing tensile strength and energy transfer, critical for muscles. Remember muscles are composed of approximately 80% water and red and infrared light is the most foundational light for life on earth, just take a look around you, do you see much red? Nope, it’s all blue and green because the red is being absorbed and used by almost everything in the environment. This make smuscle tissue more energy efficient and bolsters their continual need/function during a fast.

• UV Light Interaction with eyes and skin:
  Ultraviolet light interacts with photoreceptors like neuropsin, collagen, cholesterol, melanocytes, keratinocytes, biological water, docosahexaenoic acid (DHA), aromatic amino acids like tyrosine and tryptophan, B vitamins, sphingolipids and many more resulting in activation energy transfer to cells instigating foundational chemical reactions required for survival way beyond vitamin D synthesis. This UV light doesn’t’ need to come from a single source, it can be scattered as it is when outside such as from the Rayleigh scattering from the sky or from yellow/sand/silver-colored surfaces especially. UV light stimulates the production of melanin in skin and eyes. Melanin on our biological surfaces is involved in catalyzing the splitting of water into molecular hydrogen and oxygen. This reaction provides free electrons to fuel mitochondrial respiration, augmenting metabolic energy independently of food or external water intake.

• Bioenergetic Flow via hands and feet:
  Direct connection with the Earth's electric field introduces free electrons into the system, neutralizing oxidative stress and enhancing arterial flow. The bioenergetic meridian system, intimately tied to the arterial tree, benefits from this influx, with perspiration serving as a conductor for these environmental electrical currents. Why is perspiration salty, because salt water is a better conductor… and why do we have no hair on our palms and base of our feet? Because they are meant to be conducting electrons from our environment directly.

• Melanin as a Bioenergetic Catalyst:
  Melanin plays a pivotal role in energy transduction, particularly when stimulated by full-spectrum light. The structured water it facilitates acts as a reservoir for bioenergetic processes, increasing acting as an energy storage battery, mitochondrial efficiency and supporting the body’s energy demands during fasting.

• Hydrogen and Deuterium Dynamics:
  Metabolic water, particularly in its deuterium-depleted form, supports mitochondrial respiration by reducing the burden of heavy hydrogen isotopes. This improves the efficiency of ATP production and thermoregulation vis uncoupling proteins, aiding in maintaining energy levels and muscle functionality.

• Structured Water and Cellular Hydration:
  Endogenously produced structured water from our mitochondria predominantly amplifies cellular communication and charge transfer, essential for muscle tissue maintenance. This internal water is dynamically shaped by environmental interactions, including light exposure.

• Mineral Dynamics in Energy Flow:
  The balance of key minerals such as sodium, magnesium, and potassium is fundamental for maintaining cellular voltage gradients and energy flow. Sodium is activated by 590nm yellow light, magnesium by 285 UVB light and potassium by 760nm Infrared light, showing the critical importance of broadband spectrum light in order to optimally activate the charge channeling of the body’s DC bioelectric system. These light wavelengths and hence minerals integrate with the body’s electrical network to stabilize muscular and cellular function.

Each of these elements illustrates the intricate interplay between environmental signals and internal biological mechanisms that sustain muscle integrity during fasting. Understanding these processes opens the door to profound metabolic resilience.

3. Biophysics of Fasting and Energy Regulation

• Fasting is not just about food; it’s a biophysical reset that optimizes mitochondrial function and energy production. True fasting forces mitochondria to become more efficient by switching to ketogenesis, which improves bioelectric energy and resilience.

• ProLon, while introducing minor caloric intake, still stimulates some of these processes but may dilute the bioelectric stress that drives deeper repair and regeneration. The hormetic effect, where mild stress strengthens the body’s systems, is more pronounced during total fasting, particularly when combined with natural circadian rhythms (eating during daylight, fasting after sunset). This evolutionary design enhances fasting’s benefits by aligning with how our biology is wired to function optimally.

• When the body has access to alternate forms of energy beyond food, enhanced autophagy and deep mitochondrial and cellular repair can be experienced without muscle wastage or discomfort.

In Summary

True fasting offers unmatched biophysical and metabolic benefits, but it requires a state of metabolic readiness, specifically, leptin sensitivity, mitochondrial efficiency, efficient fat burning engines/metabolism and a foundational connection to nature to energetically support the body during the fast to ensure only upside and preserve muscle mass. ProLon serves as a steppingstone for individuals who struggle with water fasting or who have a low BMI or with a glucose-burning dominance, helping them transition into a more biologically upgraded metabolic state where multi-day water fasting becomes easier and more effective. So employing foundational health principles into lifestyle and environmental construction (no artificial light after sunset, no EMF in the bedroom, connection to outdoors/nature as much as possible during the day, grounding regularly throughout the day, using broadband lighting if indoors, building a solar callus ith IR light and watching sunrise every day, etc) and then upgrading metabolism to be more efficient with being able to burn fat as fuel easily and then try a true fast is an evolutionary route our ancestors undertook as the seasons changed.

For those who can align their fasting practices with natural rhythms, including maximizing light exposure, avoiding artificial light at night, embracing grounding and fresh air drinking deuterium depleted water and becoming cold adapted, true fasting becomes far more manageable and impactful and ProLon is likely not needed. The body can then more effectively fuel energy demands without as many hunger signals, more likely depending on n=1 context reduce the need for gluconeogenesis and preserve muscle mass. These strategies optimize mitochondrial function, increase cellular energy, and unlock the full power of fasting as a tool for health and longevity. Ultimately, tools like ProLon are helpful steppingstones/bridges, but the true power of fasting is unlocked when done naturally and in harmony with the body’s biophysics.

References

1. https://www.nejm.org/doi/full/10.1056/NEJMra1905136?utm_source=openevidence

2. https://pubmed.ncbi.nlm.nih.gov/32519900

3. https://pubmed.ncbi.nlm.nih.gov/36145236

4. https://pubmed.ncbi.nlm.nih.gov/40596030

5. https://pubmed.ncbi.nlm.nih.gov/38287649

6. https://pubmed.ncbi.nlm.nih.gov/38018193

7. https://pubmed.ncbi.nlm.nih.gov/35276792