My 3 Day Fast Guide: Before and After, How To, Benefits & Tips

I’ve wanted to try a 3-day fast for some time to see how my body responds. I understand the benefits of fasting, have done intermittent fasting, and fasted up to 36 hours in the past, but I was curious to see if there were any noticeable differences with a 3-day fast.

In this post, I’ll cover my experience with my first 3-day fast. I will break it down by my overall hunger, energy, ketone, weight loss, and waist size. The goal of this article is to provide valuable insights to those of you considering trying a 3 day fast.

Table of Contents:

• What Is Fasting And A 3-Day Fast?
• Benefits Of A 3-Day Fast
• How To Do A 3-Day Fast
• Preparing For A 3-Day Fast
• 3-Day Fast: Day-By-Day Breakdown
• My 3-Day Fast Results
• 3-Day Fasting Thoughts, Tips, & Tricks
• Who Should & Shouldn't Fast
• Pros & Cons of Fasting
• FAQs

Note: Before we get into it, fasting isn’t for everyone! Speak with your healthcare professional before starting a fast. If you want to fast for extended periods of time, 7 or more days, it should be supervised by professionals. We don’t recommend fasting for the sole purpose of losing weight. There are better alternatives for weight loss.

What is fasting?

Fasting is when you stop eating for a period of time. This might best be described through the word breakfast, where you didn’t eat overnight and then broke fast with a meal in the morning.

People have been fasting throughout time. Several reasons for fasting including religion, overall health, medical reasons, and weight loss. One thing to make sure is clear: Fasting is not starvation.

Fasting is something you will choose to do for whatever reason whereas starvation is usually out of your control. These days IF or intermittent fasting has become a mainstream tool to aid people in losing weight and feeling better all around.  

What is a 3 day water fast?

A 3 day water fast is almost exactly what it sounds like. We say almost because many people would still consider it a 3 day water fast if water, black coffee or tea is consumed. You will abstain from consuming anything else for 72 hours straight. Diet sodas and the like are off the table when it comes to a 3 day water fast. In my case I bent the rules and consumed some coffee and tea.

Benefits of 3 Day Water Fast

Perhaps the biggest reason to try the 3 day or longer fast is to help unlock the full power of autophagy. This cell recycling process takes longer than the common intermittent fasting time periods.

Fasting for 16 hours might not be enough to result in autophagy. This is based on the individual and their metabolism but it can take two to four days to achieve significant autophagy. In some animal studies there’s been findings that autophagy can take place after 24 hours of fasting while peak levels were noticed at around 48 hours of fasting. However, the exact science and timing still isn’t clear on the optimal length of a fast to trigger and exploit autophagy.

We'll get into more details of fasting in general below, but autophagy is the biggest benefit of a longer fast.

How to do a 3 day fast

Before you embark on a 3 day water fast you should take the proper precautions to ensure you stay healthy and get the most from it.

Note: You will only be drinking water, tea or coffee over the next 72 hours, no other diet drinks or food allowed.

• Decide when to start: You’ll need to decide when to start your 3 day fast. In my case, I started after dinner on Sunday night so it will end on Wednesday evening around 8pm. Choosing your start time for your fast is totally up to you and your lifestyle. Many people that work 9-5 jobs during the week like to start on Thursday night and finish on Sunday. This way they can kind of just relax at home on Saturday and Sunday when energy levels might be low. I wish I had followed this little tidbit of advice. By my third day energy levels were low and sitting in the office for a full day of work followed by a commute home via a crowded metro wasn’t the best choice. 
• Limit your carbs pre-fast: Try not to binge eat or eat a large amount of carbs prior to beginning your 3 day water fast. The goal of the 3 day fast is to get your body into ketosis. This only happens when your body has depleted its glycogen levels. So, if you eat a big pasta dinner with a side of garlic bread then cap it off with a nice fat slice of tiramisu it will take a longer time for your body to get to the ketosis point.
• Don't overeat before your fast: Eat a relatively small meal prior to you fast and limit the carbs. For example, I ate a simple chicken stir fry as my last meal before beginning my fast.
• Check with your doctor: We also need to remind you that a final prep tip and precaution is to run it by your doctor before you attempt this 3 day water fast.

3 Day Fast Prep

To get ready for my first ever 3 day fast I scoured the web, listened to a few podcasts and read a few e-books written by doctors.

Most advice was aligned with the fact that you should abstain from binge eating prior to starting the fast if you want to reap the most benefits. This wasn’t too difficult for me as I don’t overeat all too often.

I’d also consider myself semi-prepared for this short journey I was about to embark upon because I usually skip breakfasts and have a 14-16 hour window between dinner and lunch the following day.

Pre Fast

I woke up at a normal time for Sunday at 8:30am. I proceeded to read the news and check some emails. By 9:30 I made a black coffee, fed my dog and watched some Youtube videos. Over the next few hours, I began writing this post and did some research on scientific studies revolving around 3 day water fasts.

By 12, it was time for me to eat something so I met my friend for lunch. It was her turn to choose the restaurant so we ended up at a local Chinese restaurant that serves some delicious food.

I may have made a little mistake here because I ended up eating some carbs in the form of pork dumplings accompanied by some tofu and spare ribs.  Usually, you should try to go into a fast by consuming less carbs so that your body can make an easier transition to depleting glycogen levels. I’ll try to keep the rest of the day carb free, more on that in a few hours.

After lunch I got back to research and writing plus a mixture of Sunday chores (laundry, sweeping, mopping and dusting).

In the evening I completed a gym session of push exercises following the 7/3 method. Without going into too much detail about what it entails, the 7/3 method is a workout protocol that is effective and efficient. Studies describe the 7/3 method and the positive results¹.

7/3 Method:

In a nutshell, the 7/3 protocol is...

Chose a weight around 60% of your 1RM

Perform one exercise in this way:

• Set 1: 3 reps
• 15 second rest
• Set 2: 4 reps
• 15 second rest
• Set 3: 5 reps
• 15 second rest
• Set 4: 6 reps
• 15 second rest
• Set 5: 7 reps

2 minute rest then repeat one more round before moving onto the next exercise

After my workout I made a simple stir fry, spoke with my parents then went to sleep after watching an episode of Squid Game. My fast officially began at 8 pm on Sunday evening and will finish at 8 pm Wednesday night, wish me luck!

Starting My 3 Day Fast

• Starting Weight: 198 lbs (89.8 kg)
• Starting Ketone Level: .4 mmol/L
• Waist: 34 ½  inches (88cm)

Note: I took a multivitamin each day of my fast.

Day 1

Woke up at 8. Slept well, feeling refreshed and ready to tackle anything that this week brings. Made an espresso, took the dog for a walk then got ready to go to work. Energy levels feeling normal and not hungry at all. This is probably because I usually skip breakfast anyways.

It’s now 3 pm about midway through the day as I’m sitting at my computer, I still feel full of energy and have no trouble concentrating on my work at hand. I’m experiencing a little hunger at this point but nothing I can’t handle so I made some green tea to help stave off my appetite. Back to work I go, will check in this evening.

24 Hours In

It’s now 9 pm on Monday evening and I’m about 24 hours into the 3 day fast, one third down two thirds to go. My weight is just over 195lbs so I’ve dropped 3 lbs since weighing myself after dinner last night.

I’d rate my energy levels a little lower than full and my appetite at 2/10. Will finish up the day with some more water, a few emails then off to bed by 11. Still no bowel movement.

• 24 Hour Weight: ~195 lbs (88.7 kg)
• 24 Hour Ketone Level: .8 mmol/L
• 24 Hour Waist: 34 ¼  inches (87cm)

Day 2

Slept well, woke up at 7:45 with my energy levels still intact, sleep ring clocked in at 95%. I noticed a little stomach rumbling at this point but nothing too crazy. Still haven’t had a bowel movement since starting the 3 day fast.

Overall, not very hungry at this point. Feeling productive, got ready and went to work. Browsed Reddit on the subway then grabbed a black coffee just before walking into the office. Co-workers trying to tempt me into eating some delicious pastries they had brought in but I had no desire to break my fast, let’s go!

It’s now 3 pm and I could go for a bite to eat. I’m beginning to feel lethargic and a little weak when standing up too quickly from my desk. I’ve been pounding water and even threw a little salt in my last glass. All in all, my mind has been clear the entire day but I have felt a little anxious.

48 Hours In

Around 8 pm, just about 48 hours to the dot from beginning my fast I was sitting at home watching an episode of Billions when my heart started beating faster and I felt energized out of nowhere. I stopped watching the show to start writing a new blog post centered around abs and more specifically 10 packs abs and if that’s even a thing.

I then went for an hour walk around my neighborhood, water bottle in hand. I continued to work on the computer until my eyes started to twitch a bit. I figured this was my body telling me it’s time to step away from the blue light and try to get some sleep.

I ended up going to bed around midnight, as I laid down, I felt like my stomach was completely empty which gave me an almost hollow feeling. Another day without a number 2. I must’ve passed out rather quickly because next thing I knew I…

• 48 Hour Weight: ~193 lbs (87.8 kg)
• 48 Hour Ketone Level: 1.2 mmol/L
• 48 Hours Waist: 34 inches (86cm)

Day 3

…woke up at 6am with some drool on the pillow. Rise and shine, I was now headed into the home stretch. I’m usually not up this early so I wasn’t quite sure what to do with my time before heading to the office. My energy level felt low at this point and I seemed a little slower moving around than normal.

Today was hot, and wearing a mask didn’t make it any less pleasant but I soldiered on to the office. The subway ride wasn’t very an enjoyable experience today to say the least, I made it, sat down at my desk and then started my work.

It’s now 3pm and the work day seemed to drag on, at this point I’m ready to eat something. Not sure I’m hungry or I just miss the act of eating, might be more of the social aspect I’m missing as my coworkers all came back from lunch with a boisterous energy.

Anyways, I can now see the light at the end of the tunnel, only 5 more hours to go. One thing that I have noticed is that I seem to have exacerbated my foot tapping while sitting. I'm not sure if this was because I was nervous or excited to be coming close to my end goal.

72 Hours In

And, it's in the books I made it through my first 3 day fast.

• 72 Hour Weight: ~190 lbs (86.4kg)
• 72 Hour Ketone Level: 1.9 mmol/L
• 72 Hours Waist: 33 ½ inches (85 cm)

My 3 day fast before and after Results

As you can see in my before and after 3-day fasting picture above, I definitely lost some bloat. Most of the total weight loss wasn't fat, but I did drop 8 pounds in 72 hours and just a little over an inch off my waistline.

Post Fast 73 Hours In

For my first “meal” I had a bowl of beef bone broth, and let me tell you it was absolutely delicious! The saltiness and deep flavor really hit the spot. I felt reinvigorated!

To break your 3 day fast, you should eat something light like a bowl of bone broth, miso soup or a piece of fruit. You can gradually start reintroducing foods as time passes.

It’s generally recommended to take about half the time off your fast until you return completely to your old nutrition habits. In the case of a 3 day fast it should take 1.5 days before eating what you previously ate.

This slow reintroduction process will help you to avoid stomach problems. The key point here is to avoid shocking your system by over eating. Once again, the answer to this and many questions surrounding nutrition is subjective as everyone’s bodies will respond differently.

75 Hours In

The bone broth went down well, and I feel almost back to normal. The next thing I ate a few hours later was 3 eggs and a natural Greek yogurt. It was nice to be able to finally chew some food again. A spent a few hours surfing the web then hit the hay at midnight. 

Day 4

I didn't sleep that well last night, it may have been because I ate close to bedtime after not eating for three days. Which reminded me that next time I do this 3 day fast to start earlier in the evening on the first night.

I skipped breakfast as I usually do then had a nice grilled chicken Caesar salad for lunch around 1:30 pm. Finished out the work day strong and resumed my normal schedule of hitting the gym around 6. Pre-workout I had a nice vanilla hydrolyzed whey protein shake with a scoop of peanut butter. I didn't feel any loss of power or strength. It felt great to get a workout in while working up some sweat.

After returning home I made a simple baked salmon dish served with some cauliflower rice and roasted broccoli. Boy did I miss some good tasting food. Some people will say they didn't miss eating during their three day fast or was never hungry but that's not me. Growing up in a household with a first generation Italian parent means life is food and food is life.

Feeling recharged and refreshed, I'm looking forward to tomorrow as it's Friiiday and I can resume my normal eating. By the way, I was finally able to use the bathroom but unfortunately no Earth shattering shit.

Thoughts on My First 3 Day Fast:

Here are my thoughts on my first experience with 3-day fasting.

1. More Discipline Than Expected:

I wasn't too sure if I'd be able to make it the full 72 hours without eating. I was pleasantly surprised by my discipline and restraint from breaking my fast even when there were temptations all around me. Achieving this goal, I set out for myself reassured me that I'm able to pull off small feats with a little determination and dedication.

2. Would Be Better To Do With Someone:

Solo fasting while living with someone who isn't fasting can make it a tad more difficult to stay on the right course. I think it might be a nice thing to have if there was someone to go through this experience with me. It might've made me more accountable or motivated and I would've loved to hear from someone else in real time about what they were feeling like over the 3 days. 

3. Not As Bad As I Imagined:

Before starting this 3 day fast, I thought it was going to be absolute hell. While I didn't love everything about it, I did find it interesting to see how my body reacted without food.

I thought I was going to become irritable but I didn't have that feeling at all. The hunger seemed to come and go over the period of the 3 days but I'd be lying if I didn't say that I thought about eating a nice steak about halfway through.

4. Will Do Again:

Fasting provides so many amazing health benefits. I was already a fan of intermittent fasting before but now that I know that I can complete a 3 day I'll be sure to do it again. This extended fast almost felt like a detox.

It also made it seem like there were more hours in the day for some reason. I think I'll do one 3 day fast every 3 months and one 24-hour fast once a month from here on out.

Tips & Tricks for 3 Day Fast:

Ready to do a 3-day fast? These tips and tricks will help you out.

1. Work Your Way Up:

A three-day water fast isn’t the same as not eating for a few hours during the day. You should gradually build up your tolerance for fasting by following some of the IF methods above.

For example, you can start with the 12:12 method for a few weeks and then move up to 16:8 for another few weeks. Once you’re comfortable doing these daily fasting techniques, you can try the eat stop eat fasting method where you’ll be fasting for 24 hours straight.

2. Postpone If Unwell:

Don’t attempt to pull of a 3-day water fast if you aren’t in the best of health. It might go without saying, but if you’re not feeling well or you haven’t cleared it with your doctor, then you should wait until you have the green light and are feeling 100%.

3. Don’t Over Exercise:

Don’t try to be David Goggins or Cam Haines on an extended fast. Even if you’re used to intermittent fasting, you should be advised that the 3-day water fast is a little more intense.

Instead of your normal workout program, opt for some yoga or dynamic stretches. Tim Ferris recommends that you’ll get into ketosis quicker if you take a 3-4 hour causal walk the morning after beginning your fast to help deplete glycogen levels faster.

4. Don’t Binge Eat Before or After:

It’s better to start your 3-day water fast after a light meal the night before instead of pigging out to prepare for the foodless days ahead. The more carbs or sugar you eat prior to your fast, the longer it will take for your body to get into ketosis.

The same goes for breaking your fast. Don’t overeat! You should break your fast by eating something light and easy to digest, such as miso soup, bone broth, or a smoothie. Gradually increase the amount of food you consume for the following 1.5 days after crossing the finish line.

5. Schedule Properly:

Don’t make the same mistake I did. Try to time your 72-hour fast on days when you don’t have many commitments. It’s smart to do this when you don’t have to be out running errands, going to work, or having any social engagements. This will also give you time to follow the tip of taking a nice long walk during day 1 to help burn the glucose in your system.

6. Stay Hydrated:

Adequate water consumption is key to a successful 3-day water fast. Besides being an absolutely necessary substance for your body to function properly, water will help to curb your appetite if you feel yourself starting to get hungry.

At all costs, you need to stay hydrated, a common amount might be 8 glasses of water daily, but you might need more. Just be aware of how you feel, then make the necessary adjustments. If you’re thirsty, drink!

7. Don’t Cut Caffeine: 

If you normally drink coffee or tea, then you should continue to do so during your “water” fast, even if it’s not technically water. Trying to contend with a headache from caffeine withdrawal while completing your first three day fast isn’t ideal. Just make sure not to go overboard on the caffeine as it could make you feel dizzy or nauseous.

8. Check Your Ego:

If you feel like something’s not right or you’re not feeling well, then you should stop your fast immediately. Don’t jeopardize your well-being by completing the fast. You can always give it another go in the future. Visit your health care provider if you experience any issues during your 3-day fast.

9. Track Your Progress:

Next time I do a 3-day fast I will be more prepared. I did this 3 day fast on a whim, so I only had a tape measure and a scale. The best way to see how your body reacted to the fast is with real hard data. You might want to consider getting the following items ready to measure the results.

• Ketone Meter: To test your ketone levels so that you know exactly when you're in ketosis. These can be purchased online for anywhere from $30-$100. The ketone test strips won't be as accurate as the blood test.
• Body Calipers: These can come in handy to test your body fat and how much you were able to reduce it over the 3 days.
• Heart Rate Monitor: This would come in handy to reduce your nerves when doing a 3-day fast. It will help put your mind at ease when your heartbeat spikes or lowers.
• Sleep Tracker: Sleep is one of the most important aspects of life so it would be great to have some data about how your sleep is affected by your nutritional choices.

WHO SHOULD FAST

The groups who should fast include:

• People who don’t have any health conditions and aren’t part of an at-risk group can give fasting a shot. It’s good to step outside our comfort zones once in a while.
• People who are looking to unlock some of the health benefits mentioned above should try fasting.
• Even skinny fat people will reap some benefits of fasting and should give it a go.

Maybe a 3 day fast isn’t necessary for most people but at least some form of IF should be followed if you’re adamant about your long term health.  

WHO SHOULDN'T FAST

We’re not medical experts and wouldn’t give medical advice but we can look to various studies to see what the science says about fasting. You should always consult your doctor before making any drastic changes to your eating and exercise habits.

People who shouldn't fast include:

• People who have health conditions such as diabetes shouldn’t fast as it can cause dangerous fluctuations in blood sugar levels.
• Pregnant women or those breastfeeding shouldn’t attempt fasting. However, there are many pregnant or breastfeeding women around the world that do fast for religious reasons. There are multiple studies that show pregnant women who fasted during Ramadan resulted in no negative effects of fetal development².
• A few other groups of people that shouldn’t fast can include people with chronic diseases, elderly, children, and those who have struggled with an eating disorder.

What’s the difference between intermittent fasting and a 3-day fast?

The main difference between intermittent fasting and a 3-day fast is that the 3-day fast is a consecutive time period of 72 hours, while intermittent fasting is based around the concept of seesawing back and forth of eating then fasting, then eating again.

A few of the most common intermittent fasting protocols that you might come across are:

• Eat Stop Eat: This is where you will have a 24-hour fast 1-2 times a week.
• 16:8 Method: This might be the most popular IF technique as it’s easier to follow. You’ll simply have 16 hours of fasting and 8 hours of an eating window daily. If you’re getting proper sleep, then this one should be easy to stick with. A tad more rigid version would be to switch up these times to 18 hours of fasting and 6 hours of feeding. Check out our 16/8 intermittent fasting 7-day meal plan for more information on this method.
• The Warrior Diet: With this IF technique you’ll be fasting for roughly 20 hours a day and will eat one large meal at night.
• 12:12 Method: This might be the best IF programming for newbies to get used to fasting for set periods of time. The name describes exactly what it is, you can eat during a 12-hour period and then fast for the other 12 hours. If you get used to the 12:12, then you might want to gradually step up to the 14:10, where you’ll decrease your feeding by two hours and increase the fast by the same amount.
• 5:2 Diet: This isn’t technically a fasting protocol as there aren’t any set fasting time frames. With this one you will eat a regular diet for 5 days a week then drastically reduce your caloric intake for 2 days, only eating 1/5^th of the normal amount.

Benefits of Fasting:

There are multiple benefits of fasting, which is why it’s become so popular in the health industry over the past decade. Let’s have a look at some of the benefits of fasting below:

1. Reduces Inflammation:

Fasting helps to reduce inflammation in the body by lowering the monocytes in the blood. Chronic inflammation can lead to many health-related issues such as arthritis, cancer, and heart disease. We tend to overeat these days which contributes to increased inflammation. Fasting can help to mitigate this.

2. Supports Weight Loss:

Fasting can help to lose weight and fat³. By refraining from eating for lengths of time, it will make it easier to stay at a caloric deficit. Being at a caloric deficit is the same idea as following a cutting diet program.

3. Lower Risk of Type 2 Diabetes:

Unfortunately, this condition has become commonplace in today’s society. Fasting can reduce insulin resistance which in turn, can help to lower blood sugar levels. Studies have shown that intermittent fasting reduced fasting insulin levels by 20-31% while fasting blood sugar was reduced by 3-6% in pre-diabetic people⁴. It should be mentioned that these positive results might not be the same across both genders.

4. Boosts Metabolism:

Fasting has been shown to increase metabolism which will help to burn fat and lose weight. With a heightened metabolism, the body will process food more efficiently.

5. Anti-Aging:

To avoid tissue aging and diseases, the body cycles through and replenishes its cells through the process of autophagy. This cellular repair is vital for us to live longer healthier lives. Fasting has been shown to extend the lifetime of people who consume less because of the reduced toll on their digestive system.  

6. Improves Heart Health: 

Fasting has been shown to reduce LDL cholesterol and triglyceride⁵. The positive benefits of fasting on heart health can’t be understated. People who incorporate fasting into their lifestyle for the long term can be more than 70% less likely to have heart failure compared to people who’ve never fasted⁶.

7. Regulates Blood Sugar Levels:

Insulin production will decrease as you fast because the body will look to other sources of energy rather than carbs. When you fast, the body will turn to use stored fat for energy. Fasting can also help to lower insulin resistance which can aid in balancing out blood sugar levels, so you don’t fall victim to drastic spikes and crashes.

8. Boosts Hormone Production:

Human growth hormone (HGH) actually increases when fasting⁷. HGH is a hormone that the pituitary glands produce to help with cell repair, metabolism, muscle growth, strength gain, muscle recovery, and body composition.

9. Neurological Enhancements:

Fasting can lead to clearer thoughts and better overall brain functioning.  IF helps to increase the production of brain derived neurotrophic factor (BDNF) which is a protein vital to a healthy brain.  In fact, fasting may help to prevent and/or reduce risk of stroke, epilepsy, Alzheimer’s and Parkinson’s disease.

Dangers of fasting

Fasting isn’t for everyone and it should certainly be taken seriously. Fasting drastically lowers calorie intake which can result in all those amazing benefits that I just mentioned but there are also some pitfalls to be aware of when making big changes to your diet.

Some common side effects of fasting can be:

• Dizziness
• Low Blood Sugar
• Fatigue & Weakness
• Muscle Aches
• Headaches

Note: Long term fasts can bring a slew of other more serious side effects.

Fasting FAQs

Let's answer some frequently asked questions regarding fasting.

Will A Three Day Fast Reset The Immune System?

Yes, a 3 day fast can have some profound effects on a compromised immune system. A study found that prolonged fasting of at least 48 hours broke down a substantial amount of white blood cells⁸.

This triggers the stem cell regeneration of new immune cells. The study also produced results that prolonged fasting lowered the enzyme PKA, which is related to aging and increased risk of cancer and tumor growth. It’s also important to note that the toxic impact of chemotherapy was reduced by fasting for 72 hours.

How Much Muscle Will I Lose During A Fast?

With IF combined with resistance training you can maintain lean body mass⁹. In fact, IF and resistance training can maintain lean body mass while reducing body fat as long as there’s proper protein consumption and balance of energy.

Muscle loss during a fast is largely dependent on the individual’s body composition, starting point, overall health, pre-fast diet, and fitness level.

For a 3-day water fast, muscle loss will be minimal because, during this relatively short period of time, the body will consume stored carbohydrates with associated water weight. For longer fasts, muscle loss could reach .4 lbs a day once full ketosis is reached around the third day.

How Often Can I Fast?

You can fast as often as is healthy and beneficial for you. Some people have been intermittent fasting for decades. IF can become a lifestyle with no end date in sight.

We think it's good to mix up your nutritional plans just like your workout programs. You might want to try IF then mix in some longer fasts once a month.

Will Fasting Change My Bowel Movements?

Fasting may result in some bowel movement changes. Different people’s bodies will have different reactions to fasting. The effects could range from diarrhea to constipation to relatively no changes whatsoever.

It’s important to stay hydrated during your fast to help alleviate possible issues revolving around bathroom visits. Breaking the fast is where you need to be cognizant of what you eat, how much, and at what frequency to reduce your chances of experiencing stomach discomfort and/or diarrhea.

What Should I Eat Before Beginning My Fast?            

In essence, you could eat your normal diet before you begin a 3-day fast, but if you want to reap the most benefits and make the fast a tad easier then you should try to begin with your liver glycogen partially or completely depleted.

During a fast, your body will enter ketosis, this is when your liver glycogen is depleted so that your body uses ketone bodies for energy rather than glucose. If you don’t want to follow a ketogenic diet that is extremely low in carbohydrates, then you should try to consume the following foods prior to your fast:

• Legumes
• Protein
• Healthy Fats
• *Fruit (if craving for sugar)

What Should I Eat After My Fast?

There are varying opinions on what foods you should eat after breaking a 3-day water fast. However, there is a common guideline that everyone agrees on. You should never break your fast with a binge eating session. You should gradually introduce foods to your system as a large meal might cause some uncomfortable stomach issues.

Some people have smoothies or smaller snacks in intervals through the hours following a 3-day water fast. The longer the fast the longer it may take until you will feel comfortable eating larger meals. It’s important to note that it’s vital to monitor post-fast eating for longer fasts because you could experience re-feeding syndrome, where the body is negatively affected by fast changes in fluid and electrolyte levels.

You can break your 3 day fast with bone broths or fresh fruit and vegetable juice made with no preservatives. If you want something to chew on, stick with simple raw fruits and vegetables for the first day after your fast then start introducing soft cooked foods and vegetables. You may also want to have some natural yogurt with probiotic enzymes to help get your gut biome re-balanced.

Will My Metabolism Slowdown From A Fast?

No, it’s actually the other way around. Fasting will boost your metabolism. Healthy men increased their metabolism by a whopping 14% by performing a 3-day fast¹⁰. It’s thought that the increased metabolism during fasting might be due to the increase in the production of norepinephrine which is a hormone that promotes burning fat.

How Long Can I Fast?

Long-term fasting should be medically supervised as there are some risks associated with not eating for long stretches of time. If you plan on fasting for 7 days or more, then you should do so under the guidance of professionals.

A fun fact about fasting: The longest recorded fast took place in 1971 by the name of Angus Barbieri who didn’t eat solid food for 382 consecutive days. He went from 456 pounds down to 180 pounds. We don’t recommend this course of action but thought it would be interesting to know about.

Should I Use Salt Or Electrolytes During My Fast?

With a 3-day fast your sodium levels will drop but probably not low enough to be dangerous. However, longer fasts should involve electrolytes and other safety measures. To err on the side of caution, I started the mornings with a big glass of water with a pinch of salt plus a multivitamin.

Can I Exercise While Fasting?

If you’re doing a 3-day fast, then it might be a good idea to avoid anything other than light exercise. Because the body is relying on stored energy, you might not have enough in the tank to power through a normal workout. If you feel like you need to get some activity to try a nice walk, yoga, or dynamic stretching session.

How Much Weight Will I Lose During My Fast?

Everyone’s body will react differently to fasting but generally speaking, yes you will lose weight. IF is a sustainable method of losing weight and/or fat. We don’t recommend that you turn to fasting for the main purpose of losing weight.

Weight loss from fasting is one aspect, but there are more health-focused benefits of fasting than purely the pursuit of losing weight. With a 3-day fast you will lose some weight, but it will most likely be put back on once you begin eating again.

Summary: What I learned about my first 3 day fast

The 3 day fast wasn't easy for me, but it opened my eyes to life. It wasn't exactly a spiritual awakening, but it did give me some mental clarity around some issues that have been bothering me.

With all said and done, I would recommend trying a 3 day fast.

If you're thinking of trying a 3-day fast or any other type of fast, leave a comment below. Or if you've just finished completing a fast, we'd love to hear about your experience.

Interested in learning about more fasting options? Check out our guide to 20/4 Fasting and our article on Everything to Know About Intermittent Fasting For Women.

References:

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5. Bhutani S, Klempel MC, Berger RA, Varady KA. Improvements in Coronary Heart Disease Risk Indicators by Alternate-Day Fasting Involve Adipose Tissue Modulations. Obesity. 2010;18(11):2152-2159. doi:https://doi.org/10.1038/oby.2010.54 ‌
6. https://www.ahajournals.org/doi/10.1161/circ.140.suppl_1.10043
7. Ho KY, Veldhuis JD, Johnson ML, et al. Fasting enhances growth hormone secretion and amplifies the complex rhythms of growth hormone secretion in man. Journal of Clinical Investigation. 1988;81(4):968-975. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/
8. Buono R, Longo VD. When Fasting Gets Tough, the Tough Immune Cells Get Going—or Die. Cell. 2019;178(5):1038-1040. doi:https://doi.org/10.1016/j.cell.2019.07.052 ‌
9. Keenan S, Cooke MB, Belski R. The Effects of Intermittent Fasting Combined with Resistance Training on Lean Body Mass: A Systematic Review of Human Studies. Nutrients. 2020;12(8):2349. doi:https://doi.org/10.3390/nu12082349 ‌
10. Zauner C, Schneeweiss B, Kranz A, et al. Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine. The American journal of clinical nutrition. 2000;71(6):1511-1515. doi:https://doi.org/10.1093/ajcn/71.6.1511 ‌
11. Wilhelmi de Toledo F, Grundler F, Bergouignan A, Drinda S, Michalsen A. Safety, health improvement and well-being during a 4 to 21-day fasting period in an observational study including 1422 subjects. Ruscica M, ed. PLOS ONE. 2019;14(1):e0209353. doi:https://doi.org/10.1371/journal.pone.0209353

12. Kerndt PR, Naughton JL, Driscoll CE, Loxterkamp DA. Fasting: the history, pathophysiology and complications. The Western Journal of Medicine. 1982;137(5):379-399. https://pubmed.ncbi.nlm.nih.gov/6758355/