A photo capturing a person sitting in solitude, eyes closed, hands clasped in prayer, surrounded by flickering candlelight, symbolizing their devotion and contemplation during a fast for God.

How Long Should I Fast For God?

Fasting has been an important spiritual practice in many religions for centuries. For Christians who want to fast to grow closer to God, an important question arises: how long should I fast? In this comprehensive guide, we’ll provide spiritual context around fasting and give clear guidance on appropriate fast lengths and tips for a safe, meaningful fast.

If you’re short on time, here’s the quick answer: most experts recommend starting with a 1-3 day fast, and gradually working up to longer fasts of 5-10 days max. Always break a long fast slowly and carefully under medical supervision.

Spiritual Context and Meaning of Fasting

Fasting in the Bible and Christian Tradition

Fasting has been an important spiritual practice in the Bible and Christian tradition for thousands of years. Here are some key examples:

  • In the Old Testament, Moses fasted for 40 days and nights on Mount Sinai while receiving the 10 Commandments from God (Exodus 34:28). The prophet Elijah also fasted for 40 days as he journeyed to Mt. Horeb (1 Kings 19:8).
  • Jesus fasted for 40 days and nights in the Judaean Desert while being tempted by Satan and preparing to begin his ministry (Matthew 4:1-11).
  • Many early Christian leaders like St. Augustine, St. John Chrysostom, St. Jerome fasted regularly as part of their spiritual practices.
  • Throughout history, Christians have engaged in regular fasting like the 40 days of Lent and the pre-Christmas season of Advent.
  • Pope Francis has encouraged fasting saying it helps Christians ““rediscover God’s gifts” and ”self-mastery.”

These examples show fasting has long been seen as an important way for Christians to grow closer to God, train in self-discipline, and repent from sin.

Spiritual Benefits of Fasting

Fasting offers many profound spiritual benefits for those who engage in it with a sincere heart and right motives. Here are some of the most significant:

  • Deepened Prayer – Fasting helps concentration in prayer and meditation on God’s Word. When normal distractions like eating are set aside, it’s easier to focus on connecting with God.
  • Heightened Spiritual Discernment – By stripping away distractions, fasting can help Christians hear God’s voice more clearly and make better spiritual decisions.
  • Greater Humility – Fasting is an act of humility and self-denial that allows Christians to recognize their weakness and dependence on God.
  • Repentance – Fasting is often done as an act of repentance from sin and seeking God’s forgiveness and cleansing.
  • Self-discipline – Fasting strengthens a person’s ability to say no to their own desires and live in greater discipline, an important virtue in the Christian life.
  • Solidarity with the Poor – Fasting is a small way to identify with the hardships of hunger that poor people face on a regular basis.

In short, fasting brings many rewards for those who sincerely seek God. It is a proven spiritual discipline for centuries, not an easy practice, but one with great spiritual power when done with faith.

How Long Can Humans Survive Without Food?

3 Days+

The human body is an amazing machine that can withstand extended periods without food. Most healthy adults can survive without food for 3 days or more before becoming dangerously malnourished. This is because the body has energy stores that it can tap into when food is not available.

During a fast, the body first pulls energy from the glycogen stores in the liver and muscles. Glycogen is a complex carbohydrate that the body can quickly convert to glucose for energy. There is enough glycogen in the body to provide energy for 12-24 hours of normal activity.

After 1-2 days without food, the body starts burning its fat stores for energy. This process called ketosis provides a stable source of energy for the brain and other organs. Burning fat produces ketone bodies that can supply up to 70% of the brain’s energy needs.

This metabolic shift allows humans to survive for extended periods without food.

With careful monitoring and access to water, healthy adults can generally survive 3 days or more before malnutrition sets in. However, symptoms like fatigue, lethargy, irritability, and hunger pangs start to set in after just 24 hours without food.

Survival for longer than several days without food requires entering a hibernation-like state of reduced activity to conserve energy.

5 Days+

Surviving for 5 days or more without food becomes increasingly difficult and dangerous. After the initial 3-day period when the body burns through its glycogen and starts ketosis, it then has to get energy by breaking down muscle and fat.

This causes extreme fatigue and muscle wasting as the body cannibalizes itself for energy.

Other issues like electrolyte imbalances can occur after 5 days without food or water. Survival becomes precarious past this point without medical intervention. Hallucinations and cognitive impairments are likely as the body and brain become malnourished.

Still, there are exceptional cases of people surviving for up to two months without food by entering a low-energy hibernation state.

By 7-10 days without food, most organs start to deteriorate and digestive enzymes become depleted. The body loses the ability to properly digest food, putting the person at risk of shock if they try to eat again.

Surviving for over 5 days without food requires close medical support to replenish electrolytes and prevent organ failure.

40 Days with Careful Monitoring

There are extreme examples of people surviving 40 days or more without food. However, this requires daily medical monitoring and intravenous hydration to prevent organ failure and keep the body from metabolizing itself. It is not something that can be safely done alone or without medical support.

In rare cases, obese people with excess fat stores have lived up to 70 days without food under medically supervised fasting. More commonly, political hunger strikes and religious fasts have resulted in survival for up to 40 days without food, aided by intensive nutritional monitoring.

Survival beyond 30 days is life-threatening and causes lasting organ damage. Stomach lining, intestinal walls, and enzymes break down making digestion nearly impossible. With medically assisted re-feeding, the digestive system can recover but it is a long and difficult process.

Recommended Fast Lengths

Start with 1-3 Days

When beginning a fast, it’s best to start small. Fasting for 1-3 days allows your body to gradually adjust to not eating solid food. Going without food for longer than 3 days should be approached carefully, under medical supervision.

Here are some tips for beginner fasts of 1-3 days:

  • Drink plenty of fluids like water, broth, or herbal teas
  • Try easier styles like intermittent fasting or a modified fast before water only
  • Continue taking supplements if directed by your doctor
  • Break the fast gradually with gentle foods

Starting with shorter fasts helps you avoid potential health risks. It also allows you to better focus on the spiritual aspects of fasting without extreme hunger distracting you.

5-10 Days Max for Intermediate Fasters

With some fasting experience, you can gradually work up to longer 5-10 day fasts. But extreme caution is still needed.

Tips for intermediate fasts:

  • Seek medical advice before attempting longer fasts
  • Stay hydrated and supplement electrolytes
  • Take rest when needed
  • Break the fast slowly with small amounts of gentle foods

The longer you go without food, the higher the health risks. Effects like fatigue, nausea, dizziness, and heart arrhythmias can occur. Medical supervision provides an added measure of safety.

Tips for Longer Fasts

Attempting longer fasts beyond 10 days requires medical monitoring to avoid complications.

Potential tips for longer medically-supervised fasts include:

  • Staying in a clinic or hospital for closer monitoring
  • Consuming electrolyte fluids to maintain mineral levels
  • Taking supplements tailored to your situation
  • Having regular medical checks to ensure safety
  • Breaking the fast extremely slowly over days

Without proper precautions, long-term fasting can be deadly. But with medical care as needed, longer fasts may be an option for some people.

In the end, it’s important to fast safely and not go to extremes unless under a doctor’s care. Start small, and only extend fasts with caution to avoid health risks.

Safely Breaking a Fast

Refeeding Syndrome Risks

When you fast for an extended period of time, your body goes into a catabolic state and starts using stored nutrients for energy. This can deplete important electrolytes like potassium, magnesium, and phosphate.

If you refeed too quickly after a fast, you can develop refeeding syndrome which leads to dangerously low electrolyte levels. This can cause serious complications like heart arrhythmias, confusion, muscle weakness, and even death in rare cases.

The longer you fast, the higher your risk of refeeding syndrome. Fasts over 5 days put you at an increased risk.

Some signs of refeeding syndrome include fatigue, dizziness, edema, muscle cramps, and heart palpitations. If you experience any of these symptoms, stop eating immediately and seek medical attention. The key is to start refeeding very slowly to allow your body time to readjust.

Don’t overwhelm your digestive system with large meals right away. Increase calories gradually over several days.

How to Break a Fast Slowly

Here are some tips for safely ending a fast and transitioning back to regular eating:

  • Only break your fast once hunger returns – don’t eat just because your fast ended if you’re not hungry.
  • Drink plenty of water and unflavored broths at first to rehydrate and replenish electrolytes.
  • Start with easy-to-digest foods like fruits, vegetables, yogurt, soup, eggs, nuts, seeds, and bone broth.
  • Gradually reintroduce meat, grains, and fiber over 2-3 days as your digestive system adjusts.
  • Chew food thoroughly and eat slowly to prevent GI upset.
  • Limit high fat, high sugar, processed foods at first – stick to wholesome, nutritious choices.
  • Stop eating if you start to feel unwell and increase calories slower.

It’s also smart to consult with your doctor, especially if you have medical conditions or fasted for over 72 hours. With a slow, mindful refeeding approach, you can transition out of a fast safely and avoid refeeding issues.


In summary, most spiritual experts recommend starting with shorter 1-3 day fasts and gradually working up towards longer 5-10 day fasts for advanced fasters. Listen to your body, break long fasts slowly under medical supervision, and make sure your motivation aligns with growing closer to God through this ancient spiritual discipline.

We hope this comprehensive guide on how long to fast for God provides helpful guidance whether you’re new to fasting or looking to go deeper. Fasting can powerfully transform both body and soul when done carefully and prayerfully. God bless you on your spiritual journey.

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