36 Hour Fast: Benefits, Drawbacks, And Tips

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36 hour fast

36 hour fast | How it works? | How to do | Food to eat after fast | Health benefits | Risks | Tips | Who should do and avoid

Intermittent fasting is becoming increasingly popular as a way to lose weight and improve overall health. 

Among the various types of fasting, the 36-hour fast serves as a moderate option, falling between the 24-hour fast and the 48-hour fast. This type of fast can provide benefits while being less demanding on the body and lifestyle compared to longer fasts.

Let us delve into what the 36-hour fast involves and its potential benefits.

What is 36 hour fast?

A 36-hour fast, also called the Monk Fast, is a type of intermittent fasting where an individual refrains from consuming any calories for 36 consecutive hours. This means no food or calorie-contained drinks during this time.

This diet is a popular method for weight loss as it reduces overall calorie intake. Moreover, during this fast, the body enters a metabolic state called ketosis, which promotes fat loss.

Understanding how 36 hour fast works

To understand how a 36-hour fast works, it’s important to know how the body reacts to eating and hunger.

Upon ingestion of calories, the digestive system breaks them down and converts them into energy that acts as fuel for the body. The energy is commonly produced as glycogen, which is distributed to different cells and organs to maintain homeostasis.

However, an overabundance of glycogen can lead to a surplus that is eventually converted to fat, contributing to weight gain and obesity.

A 36-hour fasting period triggers a glycogen deficit due to the prolonged calorie shortfall. As a result, the body begins to catabolize stored fat to produce energy, ultimately leading to weight loss.

How to do a 36-hour fast?

A 36-hour fast demands thoughtful preparation and evaluation, starting with the selection of appropriate days to commence the fast.

According to the creators of the Monk diet, it is advisable to begin the fast at 7 am on Monday and break it at 7 am on Wednesday, as these days typically have fewer social engagements. Although 36 hours may seem like a daunting duration, a significant portion of this time is taken up by sleep.

To maintain proper hydration during a 36-hour fast, consuming non-caloric beverages such as water, plain herbal tea without sweeteners, seltzer or club soda, and black coffee is important. 

To fully reap the benefits of intermittent fasting for 36 hours, practicing it once a week for at least a month is recommended.

What to eat after breaking 36 hours of fasting?

During a 36-hour fast, the body undergoes an intensive process of cellular renewal, where old cells are metabolized, stem cells are activated, and new cells are born. 

To feed these new cells, consuming nutritious foods that are easy to digest is crucial, considering that the stomach has shrunk and digestive enzymes may take some time to return to normal levels.

So, here are some foods to eat and avoid after breaking 36 hours of fasting: 

Foods to eat

  • Bone broth 
  • Fruits
  • Raw vegetables 
  • Nuts 
  • Cooked vegetables with extra virgin olive oil 
  • Lean protein like chicken or fish cooked with extra virgin olive oil 

Foods to avoid

  • Fruit juices (As they contain sugar)
  • Alcohol and soda
  • Dairy products
  • Red meat 
  • Sugary foods and candies 
  • Refined grains 
  • Fast and processed foods 

Health benefits of 36-hour intermittent fasting

Although the Monk Fast is one of the most challenging types of intermittent fasting, it has been shown to produce significant benefits when done correctly.

1. Boosts weight loss

The 36-hour fast is a popular choice for individuals looking to lose weight as it has been shown to promote weight loss. 

Intermittent fasting [1]PubMed: Intermittent fasting and weight loss: Systematic review, including the 36-hour fast, has been found to be helpful for people who struggle with obesity.

This type of fasting can stimulate the breakdown of body fat for energy, leading to weight loss. Calorie restriction is achieved through time-restricted consumption, allowing the body to burn more calories than it takes in.

2. Lower blood sugar

Intermittent fasting can improve blood sugar management by lowering blood sugar levels through minimal insulin spikes.

It can also improve insulin resistance, protecting against type 2 diabetes. A study [2]PubMed: Effect of ramadan fasting on glycemic control and other essential variables in diabetic patients demonstrated that practicing intermittent fasting for one month can significantly improve blood sugar levels for individuals with type 2 diabetes.

3. Improved longevity

Fasting has been shown to improve both lifespan and healthspan potentially. A study [3]National Library of Medicine: The Effects of Calorie Restriction on Autophagy: Role on Aging Intervention found that occasional calorie restriction contributes to delaying and even reversing the aging process. This phenomenon is attributed to the process of autophagy, which is essentially cellular recycling.

Autophagy [4]PubMed: The effect of fasting or calorie restriction on autophagy induction: A review of the literature involves the identification of damaged cells, the recycling of their components, and the creation of new and healthy cells from the remaining materials.

According to a study [5]National Library of Medicine: Targeting Autophagy to Overcome Human Diseases, by targeting autophagy, the body can identify and eliminate damaged cells, leading to lower rates of heart disease, Alzheimer’s, and cancer. Thus, periodic fasting, such as 36-hour fasting, can promote longevity.

4. Enhanced heart health

Fasting for 36 hours a week can improve heart health, including blood sugar levels, blood pressure, triglycerides, and LDL cholesterol levels. 

A study [6]National Library of Medicine: Intermittent Fasting in Cardiovascular Disorders—An Overview on intermittent fasting found that it can also reduce inflammation, which is beneficial for the heart in the long run.

5. Induces Ketosis

When fasting for an extended period, the intake of carbohydrates is restricted, which leads the body to break down fats for fuel, resulting in a state of ketosis.

In addition to promoting fat-burning mode, getting into ketosis may also offer a range of other benefits. 

For example, it can help reset the body’s circadian rhythm, normalize blood sugar levels, improve insulin sensitivity, reduce leptin resistance, and improve mental clarity.

Although these benefits are diverse, they all contribute to the body’s ability to burn fat and improve composition.

Risks and drawbacks of 36 hours fast

Here are the risks and drawbacks of a 36-hour fast:

  • Hunger can be challenging to manage and may lead to discomfort and irritability.
  • Some individuals may experience temporary sickness, including headaches, dizziness, and nausea.
  • Overeating after a fast is a common problem, as the body craves more food after a prolonged fasting period, resulting in increased calorie consumption.
  • Fasting [7]PubMed: Effect of Intermittent Fasting on Reproductive Hormone Levels in Females and Males: A Review of Human Trials may have a negative impact on fertility for certain individuals, particularly males, as it may lead to a decrease in androgen levels.
  • Fasting for such an extended period may also affect social life, as meals and social activities may have to be scheduled around the fast.

Tips for practicing 36-hour fasting safely

Here are some tips to safely practice a 36-hour fast:

1. Pick the right day to start

To practice 36-hour fasting safely, choosing a day when you have a lighter schedule and don’t need to engage in physically demanding activities is important.

Starting on Monday evening and ending on Wednesday morning is generally recommended as there are typically fewer social gatherings on these days.

However, if you prefer a different schedule, starting on a Friday, Saturday, or Sunday, or on a day off when you can be more relaxed and not have to wake up early the next morning can also work.

2. Begin with a slow and gradual approach

If you are new to fasting, starting with shorter fasting periods before attempting a 36-hour fast is advisable. 

You can start with 12-hour fasts, then gradually increase the duration of your fasts to 24 hours, and then finally, 36 hours.

3. Ensure to stay hydrated throughout the fast

To prevent dehydration during fasting, consume noncaloric, unsweetened, non-dairy beverages like black coffee, tea, and water. 

Electrolytes such as potassium, magnesium, and phosphorus can also be supplemented to prevent the refeeding syndrome or drink bone broth which is rich in electrolytes. Enjoy a cup of bone broth twice a day during longer fasts.

4. Eat nutrient-dense meals prior to the fast

Prior to the fast, make sure that you’re eating nutrient-dense meals like vegetables, meats, and healthy fats. This helps to sustain your energy levels and reduce hunger pangs during the fast.

5. Listen to your body’s signals and act accordingly

Practicing 36-hour fasts is not a one-size-fits-all approach. Everyone’s body reacts differently to fasting, so it’s important to listen to your body and adjust the duration of your fasts accordingly. If you feel weak or dizzy, it’s best to break your fast early.

6. Break your fast carefully

When breaking your fast, it’s important to do so gradually. Begin with small food portions and slowly increase them. 

Refuel your energy stores with nutrient-dense foods like vegetables, proteins, and healthy fats, and avoid processed foods and sugar as much as possible.

Who should and should not try 36-hour fasting?

As with any dietary change or fasting practice, it’s always best to consult your personal nutritionist or doctor before trying a 36-hour fast.

Who should try 36-hour fasting?

  • Individuals who want to lose weight
  • Healthy adults with no underlying medical conditions
  • Those with high blood sugar levels or type 2 diabetes (under medical supervision)
  • People wanting to improve overall health and wellness or reduce inflammation

Who should not try 36-hour fasting?

  • Pregnant and breastfeeding women
  • People with medical conditions require food intake with medication
  • Individuals with a history of eating disorders
  • People with fertility issues

Comparing 36 hours fast with other fasting methods

Here is a table comparing different fasting methods, including 24-hour, 36-hour, 48-hour, and 72-hour fasts:

Fasting MethodDurationBenefitsConsiderations
24-hour fast1 dayWeight loss, improved insulin sensitivity.May experience hunger, may be difficult to sustain for some.
36-hour fast1.5 daysBoosts weight loss, lowers blood sugar, autophagy, and improves heart health.May experience hunger, difficult to sustain for many, requires mental and physical preparation, consultation with a doctor is recommended.
48-hour fast2 daysWeight loss, reduces inflammation, lowers cholesterol levels, boosts brain health and improves skin health.Difficult to stop food cravings, need strong determination and consultation with a doctor is highly recommended.
72-hour fast3 daysWeight loss, improved insulin sensitivity, autophagy, improves mental clarity hormone, improved blood pressure and cholesterol levels, increased immune function.May experience hunger, which is difficult to sustain for a lot of people , requires mental and physical preparation, electrolyte imbalance may occur, consultation with a doctor is strongly recommended.


Fasting for 36 hours is a good way to lose weight and improve your health. But before trying a fast, it’s essential to talk to your personal dietician and ensure you’re both mentally and physically ready for it. Also, remember to eat slowly and mindfully after you break your fast.

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