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💧 Water Fasting: A Deep Dive Into the Fastest Route to Fat Loss

Updated: May 11

Water fasting—consuming nothing but water for a set duration—has made its mark in the wellness world. From weight loss to metabolic rebooting, the minimalist approach of this ancient practice is now supported by modern research.


But before you skip your next meal (or ten), here’s important things you need to know about this powerful protocol.





One Major Advantage: The Speed


One advantage of water fasting becomes clear right away—that’s the speed. For example, assuming a consistent daily burn of 2,500 calories, in just 72 hours you’ll have burned 7,500 calories. That level of fat loss would take the average person 15 days to achieve on a traditional calorie-cutting diet.


This speed advantage has been backed by multiple studies. In one review, men who fasted intermittently over two weeks lost 3% of their body weight. Another study showed women losing 4% after just 3 weeks of periodic fasting.




🧮 No Need to Cut Calories Once the Fast is Over


Another perk? After the fast is complete, you don’t need to keep eating below your daily calorie burn.


Water fasting allows for a weekly view of calorie intake. That means some days may include a slight surplus—as long as the overall week is in deficit.


This makes fasting easier to stick with long-term, unlike the grind of daily restriction. And yes, studies show more dieters actually stay consistent on these plans.



💡 Getting Ready for a Water Fast


Before you begin, set yourself up for success:


  • 🥤 Hydrate deeply in the days leading up.

  • 🥦 Eat fiber-rich foods beforehand to avoid digestive slowdowns.

  • 🧂 Prepare electrolytes: Sodium and potassium will drop during your fast.


We will have a full pre-fasting protocol for best results. Stay tuned.



What Happens at the 16-Hour Mark


At around 16 hours in:


  • 🔋 Glycogen stores deplete

  • 🍬 Blood glucose and insulin fall

  • 😣 Hunger and fog peak


As you approach the 16-hour point in a water fast, you might feel foggy, distracted, or even irritable—this 16-hour to 28-hour window is often reported as the most difficult phase of any fast. During this period, your body undergoes a powerful metabolic shift. Yet, contrary to what you might expect, things actually begin to improve from here. With insulin levels now significantly lowered, fat cells start releasing free fatty acids into the bloodstream. These fatty acids become the primary fuel source for cells like your muscles. Your body starts shifting to fat-burning mode.



🔥 The First 5 Days of a Fast


During the first five days of a water fast, weight loss is typically more dramatic.


  • 🧊 Fasters typically lose 2 lbs an day in the first five days

  • 🧬 After that, weight loss slows down to 0.6 lbs/day

  • 💧 This early drop is mostly water weight due to lowered sodium and glycogen


This early drop is NOT primarily due to fat loss, but rather the body’s metabolic shift into ketosis. As the body transitions to burning fat for fuel, it begins shedding sodium—a key electrolyte responsible for water retention. As sodium levels drop, so does water weight, leading to the more dramatic initial results.



🧠 The Mental Shift


Something curious happens after a few days. Fasters report:


  • ✨ Increased alertness

  • 😌 Elevated mood

  • 🔥 Spikes in norepinephrine (a powerful focus-enhancing neurotransmitter)


Around this point, many fasters also report a mental clarity or uplift. Clinicians note increased alertness, improved mood, and even a mild sense of euphoria.


These effects may be due to rising levels of norepinephrine, a catecholamine that functions as a stimulating neurotransmitter. Normally near zero during sleep, norepinephrine levels surge during fasting, heightening focus and energy.



🧾 Benefits vs. Risks of Water Fasting


🟢 Benefits

🔴 Risks

Rapid fat loss

Electrolyte imbalance

Reduced insulin levels

Muscle loss if prolonged without support

Cellular repair via autophagy

Fatigue, irritability

Improved focus and clarity

Low blood pressure or dizziness

Hormonal recalibration (esp. insulin, norepinephrine)

Disordered eating triggers in some

May improve longevity biomarkers

Not recommended for pregnant women, those with diabetes, or eating disorders


🔬 A Quick Word on Autophagy


Autophagy (from the Greek auto = self, phagy = eat) is a self-cleaning process where cells break down and recycle old or damaged components. It’s like spring cleaning for your body—on a cellular level.

Water fasting is one of the most powerful triggers of autophagy, especially after 24–48 hours. The longer you fast, the more deeply this process activates. It’s associated with reduced inflammation, increased longevity, and even protection against neurodegeneration.

Stay tuned—we’ll explore the science of autophagy in greater depth in a future feature.


Wait, What About Coffee?


Good news:


There’s no evidence that black coffee or unsweetened herbal tea will spike insulin during a fast. In fact, some studies link coffee to lower fasting insulin levels—making it a friendly companion for many fasters. Stay away from sweeteners and Half & Half during water fasting!!!



✅ Safe Frequency for Most Healthy Adults:


2 times per year extended water fasting is considered perfectly reasonable for healthy individuals with adequate nutrient stores, provided they prepare properly, refeed carefully, and monitor electrolyte and metabolic health.


⚠️ Factors That Affect Frequency:


  1. Nutritional status — Frequent long fasts can deplete key nutrients.

  2. Electrolyte balance — Repeated fasts increase the risk of imbalances (esp. sodium, potassium, magnesium).

  3. Body fat percentage — Those with low body fat should not fast for extended periods often.

  4. Underlying health conditions — People with diabetes, thyroid issues, or other metabolic disorders should consult a doctor.

  5. Recovery and refeeding — You need weeks to fully rebuild nutrient stores after a long fast.


🧠 Expert Notes:


  • Dr. Jason Fung, a nephrologist and fasting expert, generally recommends longer fasts only a few times per year and suggests shorter intermittent fasting or 36- to 72-hour fasts as more sustainable for regular use.

  • Most of the metabolic benefits (like autophagy) plateau after a certain point and can be maintained through shorter fasts more frequently.



🧭 Final Thoughts


Water fasting isn’t for everyone, but for those who are healthy and prepared, it offers a powerful metabolic reset. From rapid fat loss to enhanced mental clarity, the benefits are compelling—but always weigh them against the risks, and consult a healthcare provider before starting.




💧 Bonus Material: In this video, learn how to Water Fast.


How much weight loss to expect, and also dive into the additional benefits and science.


This video is for education purposes and not medical advice. Always consult your physician.

Topics covered on this video:


(0:50) What is Fat?

(1:40) History of Dieting

(3:30) Water Fasting Speed Advantage

(5:40) Participant Retention Advantage

(6:30) Choosing Duration

(8:45) Hydration and Fiberghrelin

(9:30) Phase 1: Digestion & Absorption (0HR-4HR)

  • Fat Digestion

  • Carbohydrate Digestion

  • Insulin Explained

  • Protein and Free Amino Acid Pool

(17:55) Phase 2: Post Absorptive Period (4HR- 16HR)

  • Glycogen Breakdown

  • Hunger Levels and Ghrelin

(19:00) Phase 3 Switching Phase (16-28HR)

  • Fat Burning Increases

  • Gluconeogenesis

(20:20) Ketosis & Insulin Levels

(23:40) Weight Loss Speed

(24:10) Supplementing Electrolytes

(26:00) Fat Weight vs Water Weight

(26:40) Mental Benefits of Water Fasting

(29:30) What CAN you eat/drink?

(31:45) Muscle Loss

(32:40) Breaking a Water Fast

(33:00) Intro to Autophagy

(36:30) Anti Aging and Stem Cells

(37:00) Metabolism Slowdown Warnings

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