Fasting drinks are zero-calorie beverages you can consume during your fasting window without triggering an insulin response. The general principle is to stick to plain water, black coffee, and unsweetened tea to maintain your fast while keeping your body hydrated.
Did you know that your body can go longer without food than it can without water? It is true. This is because our bodies are made of at least 60% water, and it is necessary to keep us functioning. Without regular hydration, our bodies cannot operate as they should.
While drinking fluids is one of the main ways to stay hydrated, a good amount of water gets into our bodies through food. So while fasting, you avoid a major source of hydration. This means you need to be mindful, monitor your thirst, and make a conscious effort to drink water regularly. Exploring fasting with liquids can help you feel your best. In this article, we will go over some of the best fasting drinks and how to drink water during a fast to keep you well-hydrated and on track during your fasting window.
Disclaimer: Every fast is a personal experience. Your dietary preferences, body composition, and activity level all influence your fasting experience. It’s advisable to speak with a healthcare provider before making significant changes to your eating or drinking routine.
There is a lot of information out there about what you can and cannot consume during a fast. If you are new to intermittent fasting, all this information can easily get overwhelming.
In reality, there are just a few factors you should consider while choosing zero-calorie drinks for intermittent fasting. Let’s break them down:
Intermittent fasting works because you spend a number of hours consuming zero calories. The idea behind this type of fasting is to allow the body to tap into stored energy (1).
This process is triggered when your glycogen (carbohydrate) stores are depleted, and your body starts using stored fats for energy instead of carbs (1). Many people who follow intermittent fasting report finding it a manageable approach to eating that works with their routine.
To enter this state, you will need to deplete your glycogen stores and not consume calories during the fasting period. This means that any calorie-free drinks for fasting you choose should have zero calories.
One of the reasons intermittent fasting is a popular approach is that it allows you to deplete glycogen stores. When you deplete glycogen stores, your body begins using stored fats for energy instead of carbs (1).
The challenge with carbs during this time is that they break down into glucose and can raise insulin levels (2). When you are in a fasting state and consume something high in carbs, it brings up your blood sugar level and triggers the release of insulin to lower it, causing you to burn carbs for energy (2).
This is not what you want when fasting. You want to avoid anything that brings up your blood sugar levels.
While you are fasting, your body isn’t always able to replenish the electrolytes it loses through sweat and elimination (3). While many people feel they can manage this for a day or two, most need to pay attention to how much water and electrolytes they consume during longer periods. This is a flexible requirement, as there are other ways to replenish electrolytes without necessarily drinking a certain type of beverage.
The final consideration for choosing an intermittent fasting drink is that it should be free of additives. You should try to avoid anything that is highly processed or has a lot of artificial ingredients.
It should also be free from sugars and sweeteners. Avoid anything that contains additives like corn syrup, high-fructose corn syrup, canola oil, soy lecithin, and other common food additives, most of which contain calories or carbs that break your fast.
| Drink | Breaks a Strict Fast? | Notes |
|---|---|---|
| Plain Water | No | The best choice for hydration. |
| Plain Sparkling Water | No | Calorie-free and refreshing. |
| Black Coffee | No | Contains negligible calories. |
| Herbal Tea | No | Must be unsweetened. |
| Green Tea | No | Must be unsweetened. |
| Black Tea | No | Must be unsweetened. |
| Bone Broth | Yes | Great for breaking a fast. |
| ACV in Water | Borderline | Acceptable in flexible protocols. |
| Sports Drinks | Yes | Often contain sugar and calories. |
| Soda | Yes | High in sugar and calories. |
| Alcohol | Yes | Processed by the liver; contains calories. |
| Flavored Water (with calories) | Yes | Read labels carefully. |
Read More: Lemonade Fasting: Does It Work?
Yes, you can and should drink fluids when fasting. Restricting all liquids would risk dehydration, which can cause discomfort and impact your overall wellbeing (3). Most fasting protocols permit zero-calorie drinks to keep you hydrated and comfortable (4).
It is helpful to understand the distinction between water fasting (which involves water only) and intermittent fasting (where some zero-calorie drinks are permitted). Understanding this difference can help you choose the right approach for your routine.
The general principle is straightforward: anything with calories or that triggers an insulin response breaks the fast. If you are wondering, “can I drink when fasting,” the answer is yes, as long as you stick to approved fasting drinks. Exploring fasting with liquids makes the process much more manageable for many people.
If you want to know about intermittent fasting allowed drinks, the rule of thumb is to look for beverages with zero calories. Drinks that generally don’t break a fast include plain water, plain sparkling water, black coffee, unsweetened herbal tea, green tea, and black tea. Plain electrolyte water with no calories is also widely accepted.
On the other hand, drinks that break a fast include anything with calories, sugar, or protein. This includes sodas, juices, and coffee with milk or sugar. Sticking to allowed drinks during fasting ensures you maintain your fasting state.
| Drink | Safe During Fast? | Why |
|---|---|---|
| Water | Yes | Zero calories, essential for hydration (4). |
| Black Coffee | Yes | Negligible calories, no insulin response (5). |
| Unsweetened Tea | Yes | Zero calories, rich in antioxidants (6). |
| Juice | No | High in sugar and calories (7). |
| Latte | No | Milk adds calories and carbs (8). |
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When considering drinks while fasting, sticking to simple options can make it easier for you to stick to your schedule.
Keeping things simple as a beginner can make your fasting experience much smoother.
Water is the best drink you can start off with. There are many reasons to choose it over other beverages, including (9):
Clean, plain water is generally recommended. While fasting and drinking water, it is advisable to drink 2–3 liters per day. You may want to increase your intake if you exercise or live in a high-temperature environment.
Plain, black coffee is one of the zero-calorie fasting drinks you can have. Fasting and drinking coffee is a popular approach. When consumed in moderation, this beverage offers several benefits (10):
While it is a popular choice, coffee is not always well-tolerated by everyone. Drinking too much coffee can cause:
Many people find it helpful to keep coffee intake moderate during fasting hours and to avoid drinking it too close to bedtime. Ensure that the coffee you drink is not too strong.
Note that adding fat to coffee introduces calories and would break a strict fast; this approach is more suited to flexible fasting protocols.
Tea is another common beverage you can drink when fasting. You may enjoy it in green or black varieties. Drinking tea during fasting offers several benefits (11, 12):
However, you should avoid adding sugar, milk, honey, or agave nectar to sweeten your tea while on a fast. These additives introduce calories and will break your fast.
Now that we know what you can drink, here is a look at what you should generally avoid while fasting:
This one is a no-brainer. Soda is one of the worst drinks you can consume while fasting.
Why? It contains high amounts of sugar. Its high sugar content means it has a lot of calories, which will break your fast. Additionally, soda is one of those drinks that is commonly associated with tooth decay over time (13).
Coffee creamer often contains ingredients like hydrogenated vegetable oils, corn syrup solids, and artificial flavors. These additives have calories and carbs (14). They will break a strict fast and affect your fasting window.
Sports drinks are designed for athletes who engage in intense physical activity. They contain electrolytes and carbohydrates to replenish what is lost through sweating.
While you may need to replenish lost electrolytes, sports drinks are not your best option during a fast. They typically contain sugar, which provides calories and triggers an insulin response (15). Taking sports drinks means you are taking in calories, which breaks the fast.
Alcohol is processed by the liver, and drinking while fasting—especially on an empty stomach—places additional demands on the body. It also contains calories that break a fast (16).
While coffee or tea can be suitable, energy drinks are a different story. These beverages often have high amounts of caffeine and sugar along with other stimulants (17), which can leave you feeling overly wired and break your fast.
Fruit juice might not be carbonated, but it is still not ideal to take while fasting. Here are some reasons why:
If a drink contains calories, sugar, or macronutrients like protein or fat, it will break a strict fast. Stick to plain water, black coffee, and unsweetened tea for the best results.
Read More: 5-Day Fasting Diet Meal Plan – Detailing What To Eat During Intermittent Fasting
For a 3-day water fast, water is the only option—any other drink technically breaks it. However, many people following a strict water fast find that adding plain mineral water helps them stay comfortable.
Some modified fasting protocols allow for a bit more flexibility. For extended modified fasts, plain electrolyte water may be used to support hydration. There is a difference between a strict water fast and a 3-day modified fast, as some modified plans even allow clear vegetable broth.
Practical guidance suggests that staying well-hydrated is especially important over multi-day fasts. It is always advisable to listen to your body and consult a professional before attempting extended fasts.
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A water fast means only consuming water—no food, no other drinks, and no vitamins unless advised by a doctor. When fasting and drinking water, keeping things simple is key.
Many clinical fasting protocols emphasize a few key principles: maintaining adequate hydration (often by drinking water as needed), resting adequately, and avoiding intense exercise (19). It is also a common approach to consult a healthcare provider first.
This differs from intermittent fasting, which permits some other zero-calorie drinks like coffee and tea. Drinking water during fasting remains the foundation of any fasting practice.
Dry fasting is a practice some people attempt, but most healthcare guidance advises against it due to dehydration risk. Dry fasting means fasting without any fluid intake at all.
Dehydration risks are significant even over short periods. Since 20–30% of daily water comes from food (9), a dry fast removes this intake entirely, placing extra strain on the body. Most healthcare guidance does not recommend dry fasting due to significant health risks. We strongly recommend consulting a healthcare provider before considering this practice.
Disclaimer: Every fast is a personal experience. Your dietary preferences, body composition, and activity level all influence your fasting experience. It’s advisable to speak with a healthcare provider before making significant changes to your eating or drinking routine.
For most people, short fasts (12–24 hours) are more manageable and easier to fit into a regular routine.
Longer water fasts (24–72 hours) exist but carry higher risks and require more preparation. Extended water fasts (5+ days) are only appropriate under direct medical supervision. Individual tolerance varies widely based on health status and preparation (19). Many people find it helpful to start small and build up gradually.
Anything with calories, such as food, caloric drinks, protein shakes, or gummy vitamins, will ruin a strict fast.
Additionally, anything that triggers insulin, like sugary drinks, carbohydrate-containing foods, and some artificial sweeteners, can break the fast. There are also partial fast-breakers: drinks with a very small amount of calories, like coffee with a splash of cream. While acceptable in flexible protocols, these break a strict fast.
| Item | Does It Break a Fast? | Why |
|---|---|---|
| Splash of Milk | Yes | Contains calories and carbs. |
| Diet Soda | Debated | Artificial sweeteners may affect insulin for some. |
| Herbal Tea | No | Zero calories. |
| Bone Broth | Yes | Contains protein and calories. |
Breaking your fast with the right drink is important for easing your body out of the fasted state. Here are a few good options to consider:
Bone broth is a popular choice to take while breaking a fast. Its nutritional profile makes it ideal for easing the body back into a fed state.
A warm mug of bone broth is comforting and offers a variety of nutrients (20):
Food cravings can occur after a period of fasting. ACV diluted in water is a popular choice for people breaking a fast, as many find it helps manage hunger and ease the transition back to eating.
Raw apple cider vinegar also contains properties that many people find supportive of their daily routine (21).
Electrolyte loss is a common response during intermittent fasting (3). Some signs you may experience are dry mouth and thirst.
Pink salt contains trace minerals. A moderate pinch of salt is generally sufficient—excessive salt intake can affect fluid balance, so moderation is important. Adding a pinch of salt to water makes the drink taste better and provides gentle support.
Herbal teas are a gentle way to transition back to eating because they provide hydration and are easy on the stomach. Always talk to your doctor first about herbal teas, especially if you are on any medications or being treated for any conditions.
Here are some popular herbal teas (22):
Although you have broken your fast, go slow with sweeteners to avoid rapid blood sugar shifts.
Water, plain sparkling water, plain black coffee, and unsweetened herbal, green, or black tea are the most commonly accepted drinks during a fasting window. These beverages are generally acceptable because they contain zero or negligible calories and do not typically trigger an insulin response.
It is important to note that adding milk, sugar, or flavorings introduces calories and will break a strict fast. You can refer to the master drinks table above for a quick overview of what is generally acceptable.
Yes, most zero-calorie drinks are generally considered acceptable during intermittent fasting. The reasoning is that without calories, these drinks do not trigger a significant insulin response, allowing your body to remain in a fasting state.
However, there is some debate regarding artificial sweeteners found in diet sodas; some people find they may affect hunger signals or insulin levels. Many people choose to stick to naturally zero-calorie options like plain water or black tea to keep things simple.
Plain black coffee is generally considered not to break a strict fast (5). It contains negligible calories and minimal macronutrients, meaning it does not typically provoke an insulin response.
The important caveat is that adding milk, cream, sugar, or syrups will introduce calories and break the fast. For those practicing fasting specifically for autophagy, some practitioners prefer to avoid all non-water drinks, but for general intermittent fasting, black coffee is widely used.
Yes, plain sparkling water does not break a fast. It is completely calorie-free and offers a refreshing alternative to flat water. Flavored sparkling water is acceptable only if it contains no calories, sugars, or artificial sweeteners.
The carbonation itself does not affect the fasting state, making it a great choice to help you stay hydrated and manage hunger during your fasting window.
It depends on what you drink. Zero-calorie drinks like black coffee or unsweetened tea generally do not break a fast and can be consumed freely. Caloric drinks, such as juice, soda, or milk, will break the fast and restart your digestive processes and insulin response.
Fasting styles range from strict water-only fasting to more flexible intermittent fasting protocols, so the impact of what you drink depends on the specific rules of the routine you are following.
Disclaimer: Every fast is a personal experience. Your dietary preferences, body composition, and activity level all influence your fasting experience. It’s advisable to speak with a healthcare provider before making significant changes to your eating or drinking routine.
Choosing the right fasting drinks is essential for maintaining your fasting window comfortably. Water is the simplest and most reliable choice for staying hydrated. Plain black coffee and unsweetened teas are also popular additions that can help you feel energized without breaking your fast. It is best to avoid anything with calories, sugars, or artificial sweeteners. By sticking to these simple, calorie-free options, you can support your routine effectively.
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