People who follow the monk fast diet abstain from food for 36 hours weekly. During this time, people will only drink water and calorie-free beverages to remain hydrated.

Although no scientists have studied the monk fast specifically, research on similar fasting methods suggests that it may offer health benefits. These benefits include promoting weight loss, increasing longevity, and reducing the risk of diabetes and heart disease.

Evidence shows that less than 15% of individuals on certain fasting plans experience side effects, such as irritability and feeling cold. Researchers do not know the long-term safety risks associated with fasting, but studies have identified some areas of concern.

Keep reading to learn more about the monk fast and its potential benefits and risks.

Glass of water, part of the monk fast.Share on Pinterest
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The monk fast is one of several methods of intermittent fasting. When people engage in such fasts, they either do not eat at all, or they severely restrict food intake during certain times of the day, week, or month.

This dietary method requires individuals to abstain from food for a 36-hour period each week. During this time, they drink lots of water and other zero calorie beverages, such as tea or black coffee, to avoid dehydration.

WeFa.st, the developer of the monk fast diet, recommends doing the fast early in the week to avoid the possible interference of social obligations that typically arise later in the week and on weekends.

WeFa.st advises:

  • beginning the fast after the evening meal on Monday
  • fasting all day Tuesday
  • ending the fast upon awakening on Wednesday with a light, easy-to-digest breakfast

There are no studies that focus particularly on the monk fast, but evidence suggests that other methods of intermittent fasting may promote weight loss and offer other wellness benefits.

However, research has not examined whether the benefits are long-term. In addition, there are insufficient data on the safety of the practice, and experts do not recommend it for everyone.

A person interested in following the monk fast should talk with a doctor first.

Studies suggest that intermittent fasting, such as the monk fast, may promote weight loss, increase longevity, and reduce the risk of diabetes and heart disease.

Promotes weight loss

According to the Centers for Disease Control and Prevention (CDC), 42.4% of people in the United States had obesity in 2017–2018. Doctors advise people to aim for a moderate weight because obesity is a risk factor for metabolic diseases, such as diabetes and cardiovascular disease, which are conditions of the heart and blood vessels.

A 2020 review analyzed 27 clinical trials that took place during 2000–2019 and looked at the effect of intermittent fasting on weight loss. It found that individuals who engaged in the practice had a weight loss of 0.8–13.0% without negative effects.

Research in 2015 on rats explored the effect of intermittent fasting on body fat. After 4 weeks, the results showed that body fat was approximately 40–52% lower in the rats that engaged in intermittent fasting. The results provide a starting point for human clinical trials to investigate how fasting affects weight loss.

Boosts longevity

The National Institute on Aging reports on a mouse study that suggested that fasting has a longevity benefit. It found that the mice that ate one meal per day, which involved the longest daily fasting period, had a longer life than other mice. Age-related damage to organs also occurred later in this group of mice. The researchers hope to conduct further studies on other animals and, at a later stage, humans.

Reduces diabetes risk

Diabetes affects 34.2 million people in the U.S. The condition involves high blood sugar, which can lead to serious complications that result in long-term illness or death.

A 2021 study reviewed research published between 1990–2020 that explored the value of intermittent fasting for diabetes. Analysis indicated that the fasts reduced insulin resistance and promoted weight loss. Insulin resistance affects the ability of the cells to take up glucose from the blood, which results in high blood glucose.

The study authors concluded that the fasts are an effective, nonmedical treatment for type 2 diabetes.

Anyone with diabetes who wishes to try the monk diet should speak with a doctor first. The doctor can help them ensure that they are using diabetes medication correctly during fasting periods to avoid the complications of low blood sugar, or hypoglycemia.

Lowers heart disease risk

The World Health Organization (WHO) estimates that in 2019, 17.9 million people around the world died of cardiovascular disease. Heart disease is also responsible for about 25% of deaths in the U.S.

A 2019 review looked at studies on the effect of intermittent fasting on cardiovascular disease. The results indicated that it might reduce blood pressure, lower inflammation, and improve cholesterol levels, all of which can lower the risk of cardiovascular disease.

There is no specific research on the risks of the monk fast diet. Studies on intermittent fasting in general do show that this practice has several potential risks, though.

Research from 2015 on intermittent fasting cited studies reporting that less than 15% of people who engage in certain forms of fasting experience side effects. These include:

  • feeling cold
  • low energy
  • irritability
  • hunger

However, the authors of a 2017 review noted that the long-term effects of intermittent fasting are unknown and recommend more of this type of research to determine safety and efficacy. The review examined the potential for harmful effects of intermittent fasting and found the following areas of concern:

  • Insulin resistance in muscles: Fasting 1–2 days per week leads to overnight fluctuations in free fatty acid levels that are larger than those from a normal overnight fast. This can lead to increased insulin resistance in skeletal muscles.
  • Mood problems: Although intermittent fasting may improve mood and eating behaviors in individuals with excess body weight, it may have the opposite effect in those with a weight within the recommended range. Some studies reported that such people experienced irritability and difficulty concentrating.
  • Menstrual cycle changes: It is possible that intermittent fasting will change the frequency and length of the menstrual cycle.
  • Feasting on nonfasting days: Some people who engage in intermittent fasting tend to feast on nonfasting days rather than focusing on eating nutritious, well-balanced meals. This may have a negative effect on general health, even if the person does lose weight.

Intermittent fasting is not appropriate for underweight individuals. Doctors also do not recommend it for older adults or people who are pregnant or breastfeeding. In addition, they do not advise it for individuals with:

  • eating disorders
  • conditions, such as type 1 diabetes, that require meals at regular times
  • the need to eat regularly as a result of taking certain medications

It is important for anyone on an intermittent fast to drink plenty of water to prevent dehydration. Doing this is especially necessary because part of a person’s daily fluid intake comes from food, such as fruits and vegetables. A 2018 study that reviewed research on the safety of intermittent fasting reported two cases of hospitalizations due to dehydration.

Types of intermittent fasting other than the monk fast include:

  • Time-restricted feeding: People eat all their meals during a restricted time window, such as within a 6–8-hour period each day, and do not consume anything in the other hours. Those who opt for an 8-hour eating window will complete a 16-hour daily fast.
  • Alternate-day fasting: This involves consuming no or a small number of calories every other day. The nonfasting days do not have any restrictions.
  • 5:2 eating pattern: Individuals have 2 days of restricted eating and then 5 consecutive days of unrestricted eating.
  • Periodic fasting: This involves restricted eating on several consecutive days in a month. Eating is unrestricted on the remaining days in the month.

Learn more about types of intermittent fasting here.

The monk fast involves abstaining from food but drinking plenty of water for 36 hours each week. The developer of this dietary approach recommends starting the fast on a Monday after the evening meal and ending it at breakfast on the Wednesday.

Early research suggests that intermittent fasting methods may offer various health benefits. However, doctors advise certain individuals to refrain from practicing them. A person should check with a doctor before following the monk fast or other methods of intermittent fasting.