Welcome fellow explorers of the fasting world!✨This post is your guide to ensuring a smooth and successful 3-day fast. We’ll discuss the underlying science, the ideal time to fast, what to expect during those 3 days, how to break it the right way, my personal experience, and the potential benefits you can unlock, including – Autophagy (enhanced cellular repair), improved insulin sensitivity, better gut health, enhanced immunity, resetting eating patterns, and potential weight loss.
What is a 3 Day Water Fast
Definition: A 3-day water fast involves consuming only water (and sometimes black coffee or unsweetened tea) for 72 hours.
The goal of a water fast is to switch your body’s fuel source from carbs to fat and use ketones for energy (ketosis). This only happens when glucose stores are depleted and insulin levels remain low. An insulin response, triggered by sugar or certain calories, would disrupt this process and revert your body to burning glucose.
What Breaks the Fast?: While opinions differ slightly, consuming carbohydrates and sugar is universally considered to break a fast due to their impact on insulin. Some experts say as long as you keep your carbohydrate intake below 50 grams per day during a fast, you can maintain ketosis.
Is a 3-Day Water Fast Safe?
It’s considered to be a fairly extreme fast, potential risks include dehydration, loss of lean muscle mass, hyperuricemia (excess uric acid in the blood), electrolyte imbalance – hyponatremia (low sodium levels in the blood), decreased serum calcium and magnesium levels, sleep and digestive issues.
Certain individuals should not attempt such long water fasts. These include children and adolescents, adults over the age of 75, people who are pregnant or nursing, and individuals with an eating disorder.
In my personal experience, as a male in his 30s with a clean diet and regular exercise, the 3-day/5-day fasts feel safe. This could be due to my prior experience with intermittent fasting for over a year and incorporating occasional 24/32-hour water fasts. But if you’re brand new to the world of fasting, starting with a 3-day water fast wouldn’t be the wisest move. Think of it like weight training – you wouldn’t grab the heaviest weights first, right? The same goes for fasting. It’s crucial to ease your body in gradually, allowing it to adapt and build up its “fasting muscles” before tackling longer durations.
While long-duration fasts are not suitable for everyone – the longest recorded water fast was by a 27-year-old Scottish man named Angus Barbieri, who fasted for 392 days. During this period, he lived mainly on tea, coffee, sparkling water, and vitamins while living at home and frequently visited the Hospital for medical evaluation. He lost 276 pounds (125 kg) and set a record for the length of a fast.
Why do a 3-Day-Fast?
Fasting has several health benefits:
- Improved metabolic health – This relates to how the body processes and uses energy from food. Metabolic imbalance can contribute to poor insulin sensitivity, blood sugar regulation, and nutrient absorption.
- Better Gut Health – It gives the digestive system a break and improves the balance of bacteria in the gut. And since the gut is often referred to as your second brain, it also enhances your cognition and immune system.
However, the biggest reason to try the multi-day fast could be to help unlock the full power of Nobel-prize worthy benefit – Autophagy.
What is Autophagy?
Autophagy literally means “self-eating”. It is an intracellular housekeeping mechanism wherein your body removes and recycles damaged components. The recycled parts are turned into amino acids that can be used for fuel or to form new proteins.
It is a natural activity that occurs all the time in the cell, less when well-fed, and more during fasting, leading to a host of system-wide benefits like:
- Lower inflammation – Inflammation is a natural and necessary response to injury, infection, or irritation. It helps the body heal and defend itself. However, when inflammation becomes chronic or uncontrolled, it can lead to a variety of problems like Autoimmune diseases, Neurodegeneration and Cardiovascular issues.
- Reduced Oxidative stress – Oxidative stress occurs when the body produces too many free radicals (unstable molecules) and doesn’t have enough antioxidants to neutralize them. This can damage cells and contribute to – plaque buildup in arteries, DNA damage potentially leading to uncontrolled cell growth and cognitive decline.
- Better Cognition: Improves the transmission of nerve signals in the brain.
- Boosts Immunity – helps keep the immune system functioning normally.
How long do you need to fast for autophagy?
Depending on the individual’s metabolism and dietary habits, significant autophagy may take two to four days of fasting in humans. Autophagy is believed to begin when glucose and insulin levels drop considerably. Animal studies have shown evidence of autophagy after 24 hours of fasting, which reaches the max levels at around 48 hours of fasting. You want to stay in this state for a day/more as the journey till this point is very arduous. It’s like reaching the mountaintop and not staying there for a while to enjoy the view.
When to Begin? (some seasons are better)
Early spring – is the best time of year to burn the fat we used to insulate all winter. It is not a coincidence that most religions practice some type of spiritual fasting in the spring. Native Americans would go on fasting vision quests, Christians observe Lent, the Jewish practice Passover, and the Hindus observe Chaitra Navratri.
Winters – during cold weather it is better to fast less frequently and for shorter durations
Summers – hot weather is ideal for frequent and long fasts. Here’s why:
- Body Temperature: During fasting, the body lowers its basal metabolic rate and goes into “energy-saving mode”. As a result, the body’s temperature drops by a few tenths of a degree, leading to a feeling of coldness. This might feel refreshing in hot weather but could be challenging in colder environments.
- Physical Activity, Sunlight, and Mood: Longer days in the summer often mean more physical activity and social interaction, which can boost endorphins and overall mood. Higher levels of serotonin and dopamine, often associated with sunnier, warmer months, can contribute to feelings of well-being and reduce the tendency to emotionally eat.
- Food Choices/Cravings: In the summer, people often consume low-calorie and cool foods like salads and fruits, which are light and healthy. In contrast, during winter, the body may crave more food to generate heat and build up fat layers.
Which Weekday? – the hardest day is generally the 2nd day when the body makes the metabolic shift from glucose to fats. So starting your fast on a Thursday night seems ideal as you might have been done 24hrs fast by now, so reaching the Friday evening wouldn’t be as challenging. And the toughest days would fall on a weekend, making it easier for you to pace and schedule things your way and not the office routine. You can distract yourself by doing things you like (movies/TV shows) instead of stress-inducing office work.
# Postpone it if/when you are stressed in life(physically/mentally/emotionally) and/or sleep-deprived.
Pre-fast Meal Tips
The objective is to adjust our diet in such a way that we can achieve the metabolic conditions of Ketosis and Autophagy sooner, thereby maximizing the advantages of fasting!
Under normal circumstances, your body will use carbohydrates, fats, and protein (in that order) as preferred energy sources. After you eat, the digestive system breaks down carbs into glucose and derives energy from it. When carbs aren’t available, the body will break down fats (via fatty acid oxidation) and form ketone bodies to use as fuel. This metabolic state of fat burning is known as ketosis.
The goal of a water fast is to switch your body’s fuel source from carbs to fat and use ketones for energy (ketosis). The size and composition of your usual diet and last meal, along with individual differences, affect how quickly you enter ketosis.
To enter ketosis and initiate autophagy faster, it’s recommended to have a meal that aligns with a ketogenic diet before starting your fast. This means your last few meals before the fast need to be high in healthy fats, moderate in protein, and low in carbohydrates.
#Don’t Overeat: Eat relatively small ketogenic meals before your fast to enter ketosis sooner.
What to Expect?(day-by-day breakdown)
Embarking on a multi-day fast triggers a fascinating metabolic voyage within your body. This journey involves significant changes in how you fuel your system, transitioning from relying on carbohydrates to utilizing stored fat reserves. Here’s a detailed breakdown of the various stages involved:
Stage 1: Glycogen Depletion – The Farewell to Easy Energy (0-24 hours)
- 0-3 hours: our body readily utilizes plasma glucose (sugar circulating in your blood) as the primary energy source.
- 3-6 hours: As glucose levels begin to decline, your body starts breaking down glycogen (stored glucose in the liver and muscles) in your muscles for energy.
- 6-12 hours: Hunger pangs might become more noticeable as glycogen stores deplete.
- 12-24 hours: Gluconeogenesis starts – to compensate for dwindling glucose reserves, your body starts producing small amounts of glucose through gluconeogenesis, a process that uses non-carbohydrate sources like amino acids from muscle breakdown and glycerol from fat breakdown. However, the rate of gluconeogenesis is initially quite low, and it cannot fully meet your energy needs.
- 24 hours: The Turning Point: Entering Ketosis – After around 24 hours of fasting, your body’s glucose reserves become significantly depleted. In response, it ramps up ketone production from fat breakdown. This marks the transition to ketosis, a metabolic state where your body primarily utilizes ketones as its energy source.
Stage 2: Ketosis Transition – Embracing a New Fuel Source (24-48 hours)
24-36 hours:
- Glycogen stores start to deplete. Fat breakdown increases, and fatty acids are released into the bloodstream. Liver converts fatty acids into ketones, an alternative energy source for most tissues.
- The brain gradually adapts to using ketones for energy, although some glucose might still be available from breakdown of muscle protein.
- The body begins utilizing ketones more efficiently as an energy source, potentially leading to decreased hunger pangs and improved satiety.
- After about 24 hours of fasting, your body starts to do something really interesting: repair itself. This is a process called Autophagy. Autophagy has been shown to reduce inflammation, kill cancer cells, and clear out the misfolded proteins that are thought to cause Alzheimer’s.
36-48 hours:
The “keto flu“ might occur, characterized by fatigue, headaches, and foggy thinking due to hormonal adjustments and electrolyte imbalances.
- Replenishing electrolytes, especially sodium, potassium, and magnesium, can help mitigate “keto flu” symptoms. To do this, just add a pinch of Himalayan pink salt to your water.
- But fear not, these are typically short-lived and a sign of your body adapting to its new fuel source.
Stage 3: Deep Ketosis – Mastering the Art of Fat Burning (48 hours+)
- Welcome to the metabolic sweet spot! the body has fully adapted to utilizing ketones as its primary energy source, reaching a state known as “deep ketosis.”
- Even the brain, while still utilizing some glucose, begins to rely more heavily on ketones.
- Muscle protein breakdown slows significantly, preserving precious muscle mass.
- Hunger pangs often diminish as the body learns to extract energy from its abundant fat reserves.
- You might experience increased mental clarity and focus due to ketones being a cleaner-burning fuel.
- A study of healthy adults observed that 48-hour fasting increased human growth hormone (HGH) secretion by up to 400%. It stimulates faster muscle repair and preserving lean muscle mass. It may also expedite the healing process for wounds and more serious injuries. HGH is so effective that taking it externally is banned in professional sports and is considered doping.
#Individual experiences vary: The timing and intensity of each stage can differ depending on factors like body composition, activity level, and individual metabolism.
How to survive (Tips & Tricks!)
The Fundamentals:
- Work Your Way Up: If it feels too daunting to water fast for 3 days – for the first attempt, try using some crutches like natural coconut water (not the packed ones) as it contains electrolytes and few calories. Alternatives like one meal a day for 3 days or 3-day fruits only diet could also be good starting point.
- Stay Hydrated: Hydration is key. Drink high-quality mineral water/ lick some Himalayan salt during fasts to ensure electrolyte balance. Electrolytes, including sodium, potassium, calcium, and magnesium, are vital for proper hydration. Pay attention to the colour of your urine – pale yellow or clear indicates good hydration, while darker yellow urine suggests dehydration.
- Ride the Hunger Waves: Like sleep, hunger comes in waves (read my other article to learn more). Sipping hot water is a great hack to tackle hunger pangs and headaches. Don’t take unnecessary supplements suggested on affiliate marketing blogs.
Gamify The Whole Experience:
- Get a keto meter/CGM gadgets to gamify the journey and monitor your metabolism.
- Keep track of progress, weigh yourself 2/3 times a day, and take photos.
- Journal your emotions throughout the day. Make a video log to get stuff out of your head and you’d have wonderful insights for future fasts as our memories often get distorted over time, not videos.
- Reward yourself – buy premium waters of various kinds – with no sweeteners/flavours.
- Do it with a buddy/join an online group of fasters, it would be much easier.
How to Distract Yourself:
- Watch YouTube videos on the benefits of fasting and personal stories/join community on Reddit to stay motivated.
- Entertain yourself – enjoy movies/TV shows you’ve always wanted to see (make a list beforehand to avoid decision fatigue, it’s worse in a fasted state :P)
- Music and Walking are great ways to quickly change emotional states.
- If you have trouble sleeping, drink chamomile tea in the evening.
Avoid These Things for a Smoother Ride:
- Caffeine – switch to decaf coffee to trick the brain and avoid the crashes associated with caffeine. If you can’t go caffeine-free, then Green tea is a better alternative as the caffeine release is slower than other caffeinated beverages.
- Don’t visit areas with your favorite restaurants/ snack section of supermarkets.
- It’s time to Rest and Heal, don’t see it as free time to do long pending stress-inducing stuff.
Keep your Ego in Check & Listen to your body: Multi-day fasting can cause mild keto-flu symptoms, including transient tiredness. However, severe symptoms such as extreme fatigue, persistent brain fog, light-headedness/fainting, stomach pain, vomiting, diarrhoea, throat pain, insomnia, and chest pain are not normal and could be a sign to stop your water fast immediately. You can always give it another go in the future.
How to Break it? (it matters a lot)
One of the common problems with eating after fasting is the tendency to overeat or binge eat. Remember, there is such a thing as refeeding syndrome. The longer the duration of the fast the greater the risk and severity.
After completing your fast, prioritize a gradual refeeding process lasting roughly half the duration of your fast. Post a 3-day fast, keep approximately 1.5 days before returning to your usual portion sizes.
Start Gradually: After an extended fast, your digestive system needs time to adjust. Begin by introducing small portions of easily digestible foods. Avoid overwhelming your body with a large meal right away. Stick to small meals with lean protein and healthy fats, while keeping carbs and fiber low, to avoid tummy troubles.
What to Eat:
- Bone-broth/Soup: These are gentle on your digestive system and provide hydration and some electrolytes.
- Protein-Rich Foods: Incorporate items like eggs, chicken, fish, or tofu. These help rebuild muscle and provide energy.
- Ripe Fruits: Bananas, avocadoes, melons, and applesauce are good choices. Bananas are rich in electrolytes like potassium and magnesium and are high in carbs while being gentle on the stomach.
- Fermented Foods/Probiotics: Fermented foods like yogurt(unflavoured/unsweetened), kefir, sauerkraut, kimchi, miso, tempeh, and pickled vegetables are among the best foods to eat to break a fast.
- Cooked Vegetables: Well-cooked, mashed, or steamed options like carrots, potatoes, and green beans.
What to Avoid:
- Processed Foods/Desserts: Overeating after fasting is especially common if you consume processed foods and high-glycaemic carbs such as breakfast cereals, white bread, pasta, bagels, cookies, pastries, and jelly, that often contain added sugars. These foods can cause a rapid spike in blood sugar, and it is very easy to consume a lot of the food quickly and not feel particularly full, leading to overeating.
- Sugary drinks: Avoid soda, sugary juices, and sports drinks as they can cause blood sugar spikes and discomfort.
- Fiber intake: Introduce fiber gradually. While essential, high-fiber foods like raw vegetables and whole grains can be challenging to digest initially and cause bloating.
- Raw Cruciferous Vegetables: While healthy, raw broccoli, cauliflower, and cabbage can cause gas and bloating. Cook them before consuming.
- Legumes, Nuts, and Seeds: These foods contain complex carbohydrates and fiber, which might be tough on your stomach right after fasting.
#Bottomline – Choose simple, easy-to-digest foods. Eat small portions and chew slowly to gently wake up your digestion without going overboard and possibly losing the benefits of your fast.
My Personal Journey
Building up to a Longer Fast:
For over a year, I’d been dipping my toes into intermittent fasting (16/8) and even dabbled in a few 24-hour water fasts. But a multi-day water fast? Like most people, I was terrified. The mental hurdle seemed insurmountable.
Finding Inspiration:
Then, a conversation with a friend changed everything. This guy, a total foodie, someone who wouldn’t skip a dessert for the world, casually mentioned doing regular 3-day water fasts as part of his Jain religious practice each year. My jaw dropped. If he could do it, surely I could too! It was more of a “monkey-see, monkey-do”, but it worked.
Gradual Approach:
However, for the first 5-day water fast I was a bit anxious. So just to be on the safer side, to maintain electrolyte balance, I consumed ~3-4 coconuts’ water during the whole day – thinking that it was mostly water with electrolytes and minimal calories. I guess it worked as a crutch, but finishing it helped boost confidence.
Progression to a Purist Approach:
After successfully completing the first 5-Day fast, I transitioned to a stricter approach with high-quality mineral water and sticking to Himalayan salt only for the electrolyte aspect. Here’s the thing: starting slow with a little support is okay! Going all-in from the get-go can lead to frustration and quitting.
Challenges and Solutions:
Day two is the real beast – your body’s switching fuel sources. Headaches and sleep disturbances are common. However, I found staying busy, walking regularly (avoid exertion), and taking naps when needed helped manage these effects. Additionally, sipping hot water with a pinch of salt helped control hunger pangs.
To keep things exciting and maintain electrolyte balance, I bought all sorts of premium waters from the supermarket to drink during fasts, which I would otherwise find priced unfairly (read Perrier). I like the idea of telling a few friends/colleagues that you are doing this challenge as it keeps you accountable and their sheer astonishment each morning gives you enough high to last another day!
Overall, fasting has been a journey of self-discovery. It’s tough, but doable, and the sense of accomplishment is incredible.
Summary
- Summertime is better than winter for long fasts.
- Don’t do it at a time when you have stress in life.
- Since 2nd day is the most challenging, try scheduling it on a weekend.
- Keep the last few meals smaller with higher fat% to enter ketosis sooner.
- Drink high-quality mineral water/ lick some Himalayan salt during fasts to ensure electrolyte balance.
- Pay attention to the color of your urine – pale yellow or clear indicates good hydration, while darker yellow urine suggests dehydration.
- Sip hot water to tackle hunger pangs and headaches.
- Don’t exert, it’s healing time. Walks are a great distraction and mood boosters.
- Break your fast gradually to avoid refeeding syndrome. Eat small meals with lean protein and healthy fats, while keeping carbs and fiber low for 1.5 days.
- Remember it’s more of a mental game than physical!
How often can I do a 3 day fast?
Hi Casie,
It’s very hard to give a general guideline on the frequency of a 3 day fast. It depends on various factors like your current health, age, gender, medical history, body fat%, occupation and climate you live in. Also, what’s your objective of doing it. Anything extreme done too frequently needs medical supervision for safety.
Having said that, it’s better to do 3 day fast less frequently and stick to frequent 1 day fasts(say once 2 weeks, preferably on Ekadashis(certain days based on phases of moon)). Intermittent fasting is also a great way to cultivate a lasting lifetime habit. If you do the last 2 practices, 3-day fast won’t even feel necessary.
Personally, I used to do 3D/5D ones earlier, now I don’t as my body fat has already dropped to ~10% and body weight is lower than doctors advise. Thus now I would do multi day fasts only if there is a health issue where long fasts help or to use it as a tool for spiritual growth.
Hope it helps :]
hy i m harlee i want to fasting for 21 days is it impossible?
Hi Harleen, it’s not impossible but not advisable without medical supervision. Also it also depends on how much fat reserve do you have, as your body essentially starts to burn fat for fuel while fasting. Gradually build upto 3-5 days, which are safe limits. Besides fasting for weeks is not a magical solution to anything. Consistency over intensity is almost always a better approach.
is it OK to take vitamins daily while fasting?
Hi Ruben. I am not sure about that. Maybe consulting a doctor is better if you have a medical condition that requires daily supplementation of Vitamins. If you don’t have any prescriptions then simple Himalayan/Celtic sea salt is all you need as just electrolytes are needed if the duration of fast doesn’t exceed 5 days. Besides other than Vit B and C, rest are fat soluble vitamins so I am not sure if they would get absorbed as much.