Can you drink water during fasting time? What the experts say

December 31, 2025 •

4 min read

According to Healthline, drinking water during an intermittent fast is not only generally permitted but also recommended to help you stay hydrated. While water is fine for most fasts, the question "can you drink water during fasting time?" has different answers depending on your specific reason for abstaining.

Quick Summary

The allowance of drinking water during a fast depends on the type of fast being practiced. While plain water is acceptable for intermittent fasting, it is strictly forbidden during dry fasts for medical or religious reasons. Maintaining hydration is crucial for most fasting protocols.

Key Points

Type of Fasting Matters: The primary factor determining if you can drink water is the type of fast you are following, such as intermittent vs. dry fasting.
Intermittent Fasting Allows Water: For intermittent fasting, drinking plain water is not only permitted but encouraged to help you stay hydrated and manage hunger.
Dry Fasting Forbids Water: A dry fast, often for religious reasons, prohibits all liquids, including water, and requires careful management to avoid dehydration.
Calorie-Free Beverages: For most health-related fasts, other calorie-free drinks like black coffee and unsweetened tea are acceptable substitutes for plain water.
Medical Supervision is Key: Always consult a healthcare provider for guidance, especially regarding medical fasts before procedures or if you have underlying health conditions.
Hydration Benefits During Fasting: Drinking enough water during a fast can help suppress appetite, boost metabolism, and prevent dehydration-related side effects.

Understanding the Basics: What is Fasting?

Fasting is the practice of voluntarily abstaining from food and sometimes drink for a specific period. It has been practiced for thousands of years for spiritual, religious, and health-related reasons. While the concept is simple, the rules and protocols can vary significantly depending on the type of fast being followed. This variety is the key to understanding whether you can drink water during your fasting time.

Why Water Is Usually Permitted in Health-Based Fasts

For popular health-related fasts, such as intermittent fasting (IF), water is not only allowed but highly encouraged. The reason for this lies in the science of how fasting works to achieve its metabolic benefits. The goal of IF is to lower blood sugar and insulin levels, allowing the body to enter a metabolic state where it burns stored fat for energy. Since plain water contains no calories, it does not trigger an insulin response or raise blood sugar, thus maintaining the fasted state. Staying hydrated is essential during these periods to:

Prevent dehydration, which can cause fatigue, headaches, and dizziness.
Help suppress appetite and reduce hunger pangs.
Support the body's natural detoxification processes.
Maintain proper electrolyte balance, especially during longer fasts.

The Major Exception: Dry Fasting

For certain types of fasting, water is completely off-limits. This is known as a dry fast, and it is most commonly associated with religious observance. For example, during Ramadan, Muslims abstain from all food and drink, including water, from dawn until sunset. Similar complete abstentions may be required in other religious practices, such as Yom Kippur in Judaism. Dry fasting is an advanced form of fasting and should not be undertaken without serious consideration and understanding of the potential risks, primarily dehydration. Individuals with certain health conditions are advised against dry fasting entirely.

Medical Fasting Protocols

Fasting is also required before certain medical procedures, particularly those involving anesthesia. The purpose is to ensure the stomach is empty to minimize the risk of complications like aspiration. In these cases, the rules regarding water are very specific and must be followed exactly. Some procedures may permit clear liquids, including water, up to two hours before the procedure, while others may require complete abstinence from midnight onwards. It is critical to always follow the specific instructions given by your healthcare provider.

Fasting Protocols and Water Consumption: A Comparison Table


Type of Fasting	Can You Drink Water?	Key Rules & Rationale
Intermittent Fasting (IF)	Yes	Water is calorie-free and does not break the metabolic fast. Staying hydrated is recommended.
Water Fasting	Yes	By definition, this fast involves consuming only water for a specific period (e.g., 24-72 hours).
Religious Fast (e.g., Ramadan)	No	Requires abstention from all food and drink, including water, during daylight hours.
Medical Fasting (Pre-Surgery)	Check with Doctor	Varies by procedure. Some may permit water up to two hours before, but you must follow specific medical instructions.
Dry Fasting	No	Prohibits all liquids and food. An advanced fasting method with higher health risks, including dehydration.

Beyond Plain Water: What Else Is Permitted?

For those following intermittent or water-only fasts, other calorie-free beverages may be acceptable, depending on the strictness of the protocol. These often include:

Black coffee: A zero-calorie beverage that can help curb appetite. Additives like milk, cream, or sugar will break your fast.
Unsweetened tea: Herbal or green teas are typically fine, as long as no sugar or honey is added.
Sparkling water: Flavored, unsweetened sparkling water is also an option.
Lemon water: A small amount of lemon juice (which contains minimal calories) is unlikely to affect your fasted state for most protocols.
Bone broth: Some people consume bone broth during longer fasts to replenish electrolytes, though it does contain a small number of calories.

It is always crucial to read labels carefully, as added sugars or artificial sweeteners can disrupt the fast's metabolic benefits. For a more in-depth look at what breaks a fast, you can consult authoritative resources like Healthline's article on the topic.

Conclusion

While the answer to "can you drink water during fasting time?" depends on the specific protocol you are following, for the majority of health-related fasts like intermittent fasting, the answer is a resounding yes. Staying properly hydrated with plain water is a cornerstone of safe and effective fasting. However, for dry fasts undertaken for religious reasons or specific medical procedures, strict adherence to abstaining from water is required. Always understand the guidelines of your chosen fast and consult with a healthcare professional, especially for extended fasts or if you have underlying health concerns.

How to Stay Hydrated While Fasting

To maintain optimal hydration during your fast, consider these tips:

Start the day with a glass of water: Drink a full glass of water upon waking to kickstart hydration.
Set reminders: Use a mobile app or alarm to remind you to drink water throughout the day.
Listen to your body: Drink when you feel hungry or thirsty, as these sensations can often be confused.
Add flavor naturally: Infuse water with slices of cucumber or lemon for a refreshing taste without breaking your fast.
Consider electrolytes for longer fasts: For fasts longer than 24 hours, consider adding a pinch of salt to your water to replenish electrolytes.
Avoid strenuous activity during dry fasts: For fasts where no water is allowed, minimize physical exertion to reduce water loss through sweat.

Frequently Asked Questions

For most blood tests that require fasting, it is generally acceptable to drink plain water. However, you should always confirm the specific instructions with your doctor or healthcare provider, as some tests have stricter rules.

In most intermittent fasting protocols, adding a small amount of lemon juice to water is acceptable. The calorie count is minimal and typically won't interfere with the metabolic benefits. Avoid adding sugar, honey, or other sweeteners.

Yes, calorie-free beverages like black coffee and unsweetened tea are generally permitted during most intermittent fasts. Avoid any additives such as milk, cream, or sugar.

Dry fasting carries a high risk of dehydration and is not suitable for everyone. It is typically practiced for short periods for religious reasons. It is strongly recommended to consult a healthcare professional before attempting a dry fast, especially for extended periods.

While fasting, you should maintain your usual daily water intake, which is typically recommended to be around 2-3 liters for most adults. Listen to your body and drink whenever you feel thirsty.

Not drinking water during a fast can lead to dehydration, which may cause headaches, dizziness, constipation, and fatigue. This is especially risky during extended fasts where fluid intake is critical.

Yes, drinking water can help reduce hunger pangs by providing a sense of fullness and keeping you occupied. Staying well-hydrated is a key strategy for managing appetite while fasting.