How Often Should You Do Monk Fast? Guidelines and Safety

January 7, 2026 •

5 min read

Studies have shown that a twice-weekly 36-hour fast can increase circulating ketones by fourfold compared to shorter fasts, highlighting the metabolic shift that occurs. This intense fasting regimen, known as the monk fast, requires careful consideration of frequency and adherence to safety protocols for successful implementation.

Quick Summary

A monk fast, a 36-hour calorie-free regimen, is typically practiced once a week by healthy, experienced fasters. Frequency is highly individual and depends on one's fasting experience and overall health. A gradual approach, starting with shorter fasts, and prior medical consultation are crucial for a safe practice.

Key Points

Optimal Frequency: For most healthy adults, once per week is the recommended and safest frequency for a monk fast.
Start Gradually: Beginners should not jump into a 36-hour fast. Instead, start with shorter intermittent fasting periods like 16:8 to prepare your body.
Prioritize Hydration: Drinking plenty of water and other calorie-free beverages is crucial throughout the 36-hour fasting period to prevent dehydration.
Consult a Professional: Always talk to a doctor before starting a new fasting regimen, especially if you have underlying health conditions or are pregnant.
Break the Fast Mindfully: When ending the fast, consume a light, easily digestible meal first to prevent overwhelming your system.
Be Mindful of Diet: On non-fasting days, maintain a healthy, balanced, and nutrient-dense diet to avoid deficiencies and prevent overeating.

Understanding the Monk Fast: What is a 36-Hour Fast?

The monk fast is a form of prolonged intermittent fasting that involves abstaining from all calories for 36 hours. During this time, only water and other non-caloric beverages like black coffee or plain tea are consumed. The practice is inspired by the disciplined routines of monks and has gained modern popularity for its potential health benefits, which stem from the extended fasting period. After approximately 24 hours without food, the body exhausts its glycogen stores and switches to burning stored fat for fuel, a metabolic state known as ketosis. This process is believed to trigger cellular repair mechanisms like autophagy, which is where the body cleans out damaged cells and regenerates new, healthy ones.

The typical monk fast schedule is designed to be performed once per week. For instance, one might finish dinner on Monday evening and not eat again until breakfast on Wednesday morning, effectively spanning a 36-hour window. This weekly pattern allows for a substantial fasting period while also providing six days of regular eating, which is key for nutrient replenishment and preventing nutritional deficiencies.

Recommended Monk Fast Frequency: How Often is Optimal?

For most healthy adults, performing a monk fast once per week is the most widely recommended and sustainable frequency. This schedule allows the body to activate key metabolic pathways without placing excessive stress on the system. Evidence suggests that fasting once weekly can improve insulin sensitivity and support weight management. For those who tolerate the fast well after several weeks of practice, an increase to twice per week might be considered, but this is not recommended without clinical supervision. More frequent attempts beyond this, such as alternate-day 36-hour fasts, are considered extreme and come with higher risks. Longevity and health benefits from fasting often come from consistency over time rather than short, intense bursts of restriction.

How to Build Up to a Monk Fast

Attempting a full 36-hour fast from the outset is challenging and can lead to adverse effects like fatigue, dizziness, and intense hunger. A gradual approach is the safest and most effective way to prepare your body. Here is a step-by-step method for beginners:

Start with Time-Restricted Eating: Begin with a less intensive method, such as 16:8 intermittent fasting, where you fast for 16 hours and eat during an 8-hour window each day.
Transition to a 24-Hour Fast: Once you are comfortable with 16:8, try a 24-hour fast, such as the "Eat-Stop-Eat" method, once or twice a week. This bridges the gap to the longer fast.
Attempt a 36-Hour Fast: After your body has adapted to 24-hour fasts, you can attempt the 36-hour monk fast once a week. Choose a day with low activity and no major social obligations.

Benefits vs. Risks: What to Consider


Feature	Monk Fast (36-Hour)	Standard 16:8 Intermittent Fasting
Frequency	Once to twice per week	Daily
Difficulty	High; requires significant discipline	Lower; easier to incorporate daily
Fast Duration	36 hours	16 hours
Ketosis	Reached more reliably due to longer duration	Possible, but not guaranteed; depends on diet
Main Benefits	Autophagy, cellular cleanup, significant fat loss	Improved insulin sensitivity, basic weight loss, metabolic health
Main Risks	Dehydration, fatigue, dizziness, nutrient deficiency	Less significant risks; potentially overeating during feeding window

Potential Benefits

Weight Loss and Fat Burning: By extending the fast beyond 24 hours, the body is more reliant on its fat reserves for energy, which can lead to significant fat loss.
Autophagy Activation: The prolonged fasting period promotes cellular recycling, a process that can help remove damaged cell components.
Improved Metabolic Health: Studies suggest that intermittent fasting can improve insulin sensitivity and aid in managing blood sugar levels, reducing the risk of type 2 diabetes.
Mental Clarity and Focus: Many people report enhanced focus and mental clarity during fasting periods as the body shifts its energy use.

Associated Risks

Dehydration: A large portion of daily fluid intake comes from food, so special attention must be paid to water consumption during a fast to avoid dehydration.
Fatigue and Headaches: These are common side effects, especially when starting out.
Nutrient Deficiencies: Inadequate nutrient intake on non-fasting days can lead to deficiencies, emphasizing the need for a healthy, balanced diet.
Muscle Loss: Prolonged calorie restriction can cause the body to break down muscle for energy. This is a greater concern for more frequent or prolonged fasting than a weekly monk fast.
Hormonal Imbalance: Some studies suggest that prolonged fasting may negatively impact hormonal balance in women more than men.

Safe Practices for a 36-Hour Fast

Prioritize Hydration: Drink plenty of water throughout the 36-hour period. Calorie-free electrolytes can also be helpful to maintain balance.
Choose the Right Day: Schedule your fast on a day with low physical activity to manage potential fatigue and low energy.
Break the Fast Gently: Reintroduce food slowly with a light, easily digestible meal like bone broth, soup, or a small portion of healthy fats and protein. Avoid breaking your fast with a large, heavy meal.
Listen to Your Body: Pay close attention to how you feel. If you experience severe dizziness, prolonged headaches, or extreme weakness, it's a sign to end the fast early.
Eat Mindfully on Non-Fasting Days: Ensure your feeding days are filled with nutrient-dense, wholesome foods to replenish your body and prevent overeating.

Before undertaking any fasting regimen, especially a prolonged one, it is crucial to consult with a healthcare provider. This is particularly important for individuals with pre-existing conditions like diabetes, thyroid issues, or a history of eating disorders, as well as those who are pregnant or breastfeeding. For more information on the safety of fasting, see this informative guide on Healthline.

Conclusion: Finding the Right Balance for Your Health

For a healthy and sustainable approach, the frequency for a monk fast is most often once a week. This schedule allows the body to reap the potential benefits, such as weight management and metabolic improvements, while reducing the risks associated with more frequent, prolonged fasting. Beginners should always work their way up to a 36-hour fast gradually. Ultimately, the best frequency is the one that aligns with your health needs, lifestyle, and medical guidance. Always prioritize safety, proper hydration, and nutritious eating on non-fasting days to maximize the benefits and minimize potential side effects.

Frequently Asked Questions

Yes, for most healthy individuals, performing a monk fast once a week is sufficient to achieve the desired metabolic benefits, including fat burning and improved insulin sensitivity, while remaining safe and sustainable.

It is not recommended to do a monk fast more than twice a week, and only experienced fasters who tolerate it well should consider this. It is crucial to have medical supervision before attempting more frequent prolonged fasts due to increased health risks.

Beginners should build up to the 36-hour fast gradually. Start with a less intensive method like 16:8 intermittent fasting and progress to 24-hour fasts before attempting the full monk fast.

Common side effects can include fatigue, headaches, irritability, dizziness, and hunger. Staying well-hydrated and listening to your body's signals can help mitigate these effects.

During the 36-hour fast, you should only consume water and other zero-calorie beverages such as black coffee or plain tea. Staying well-hydrated is essential.

While prolonged calorie restriction can lead to muscle loss, a weekly monk fast is less likely to cause this issue. Ensuring a balanced, nutrient-rich diet on non-fasting days can help preserve lean body mass.

Individuals who are pregnant, breastfeeding, underweight, or have a history of eating disorders should not attempt a monk fast. Those with pre-existing medical conditions like diabetes should only do so under strict medical supervision.

Break the fast gently with a small, easily digestible meal like soup or bone broth. Wait for that to settle before resuming normal eating. Avoid large, heavy meals immediately after the fast.