Which drink is good during fasting?

November 3, 2025 •

4 min read

Research shows that drinking plenty of calorie-free fluids is crucial for hydration during fasting, as a significant portion of daily fluid intake typically comes from food. The question of "which drink is good during fasting" is fundamental for anyone pursuing this wellness strategy, as choosing the right beverages is key to success without breaking its benefits.

Quick Summary

Learn which calorie-free beverages like water, black coffee, and unsweetened tea are best for fasting. This guide outlines which drinks to avoid to prevent breaking your fast and compromising your goals.

Key Points

Water is Supreme: Plain and sparkling water are the safest, most essential drinks during fasting as they contain zero calories.
Black Coffee is Permitted: Unsweetened black coffee can provide a low-calorie energy boost and suppress appetite without breaking your fast.
Stick to Unsweetened Teas: Herbal, green, and black teas are excellent calorie-free alternatives to water, as long as no sugar, milk, or honey is added.
Avoid All Sugars: Any drink with sugar, including fruit juices, sodas, and sweetened beverages, will immediately break your fast by spiking insulin levels.
Limit Artificial Sweeteners: Some zero-calorie sweeteners may still trigger a metabolic response in some individuals, so sticking to pure, unsweetened drinks is safest.
Consider Electrolytes for Longer Fasts: Adding a pinch of salt to your water can help replenish essential minerals lost during prolonged fasting periods.

The Importance of Proper Hydration During Fasting

Staying hydrated is essential for overall health, and this becomes even more critical during a fast. When you restrict your food intake, you also lose a significant source of water, which is naturally present in fruits, vegetables, and other foods. Dehydration can lead to fatigue, headaches, and dizziness, all of which can make sticking to your fasting schedule challenging. By consciously choosing the right beverages, you can support your body's functions, curb hunger pangs, and maintain energy levels throughout your fasting window.

Fasting-Friendly Drink Options

For most fasting protocols, the primary rule is to consume beverages with zero or very few calories. This prevents a significant insulin response that would interrupt the fasted state.

Plain and Sparkling Water

Water is the gold standard for hydration and is always acceptable during a fast. Both plain and sparkling water (as long as it's free of added sugar or sweeteners) are excellent choices. Sparkling water can also help create a feeling of fullness, which can be useful for curbing hunger. For longer fasts, adding a pinch of Himalayan salt to water can help replenish lost electrolytes.

Black Coffee

Plain black coffee is a popular and safe choice for many fasters. It contains minimal calories and won't trigger an insulin spike. The caffeine can offer a mental and metabolic boost, suppressing appetite and enhancing fat burning. However, moderation is key, as excessive caffeine on an empty stomach can lead to jitteriness or dehydration.

Unsweetened Teas

Like coffee, teas are generally fast-friendly as long as they are unsweetened and contain no added milk or cream. Different types of teas offer various benefits:

Green Tea: Contains catechins and antioxidants that support metabolism and cellular repair processes (autophagy).
Black Tea: Also contains antioxidants and a moderate amount of caffeine for a gentle energy lift.
Herbal Teas: Caffeine-free options like chamomile, peppermint, or ginger can be soothing and may help with digestion or cravings.

Diluted Apple Cider Vinegar (ACV)

Some find that drinking a small amount of diluted apple cider vinegar can help control appetite and support blood sugar levels during a fast. The typical ratio is 1-2 teaspoons of ACV mixed into 8 ounces of water. It's crucial to dilute it properly and consider using a straw to protect tooth enamel from the acidity.

Comparison Table: Fasting-Friendly Beverages


Beverage	Calories (per 8oz)	Caffeine Content	Key Benefits During Fasting
Plain Water	0	None	Essential hydration, keeps you full, zero metabolic impact
Black Coffee	~4	High	Boosts metabolism, suppresses appetite, enhances fat burning
Green Tea	~2.5	Low-Moderate	High in antioxidants, supports metabolism, aids cellular repair
Herbal Tea	~2.5	None	Soothes digestion, calming properties (depending on herb)
Sparkling Water	0	None	Hydration with a satisfying fizz, helps with fullness

Drinks to Avoid While Fasting

Any beverage that contains calories, sugar, or ingredients that cause an insulin spike should be avoided during a fast. These include:

Sugary drinks: Regular sodas, fruit juices (even fresh-squeezed), sweetened teas, and sports drinks. The high sugar content will immediately break your fast.
Milk and Creamers: Whether dairy or plant-based, milk and cream add calories from carbohydrates, fats, and protein that will disrupt the fasted state.
Diet Sodas: While zero-calorie, some artificial sweeteners can trigger an insulin response in certain individuals, potentially disrupting the fasting process and increasing cravings.
Alcohol: All alcoholic beverages contain calories and interfere with fat-burning processes.
Bone Broth: Contains calories and protein, so it will technically break a fast. It's best used to transition back to eating or for specific, less strict fasting protocols.

The “Dirty Fast” Debate

For those who find a strict fast difficult, the concept of a “dirty fast” sometimes comes up. This involves consuming a small amount of calories (often from fats like in bulletproof coffee) during the fasting window. While this may make fasting more manageable for some and keeps blood sugar low, it technically breaks the clean fast, as it interrupts processes like autophagy. The best approach depends on individual goals, but for maximizing the benefits of a true fast, avoiding all calories is recommended.

Conclusion: Making the Right Choice for Your Fast

Ultimately, the best drink during fasting is a zero-calorie, unsweetened one. Plain water should be your first and foremost choice for hydration and satiety, especially since dehydration is common during fasting periods. For those needing a pick-me-up or some variety, unsweetened black coffee, green tea, or herbal teas are excellent options. Remember to avoid any additives like sugar, milk, or artificial sweeteners that can negate your fasting efforts. By sticking to these simple and effective beverage choices, you can stay hydrated, focused, and on track to meet your fasting goals. For more in-depth information on the science behind intermittent fasting, consider exploring resources from Johns Hopkins Medicine.

Frequently Asked Questions

No, plain black coffee does not break a fast. It contains virtually no calories and can even enhance some fasting benefits, such as boosting metabolism.

Yes, you can drink tea while fasting, but it must be unsweetened and without any milk or cream. Herbal, green, and black teas are all safe choices.

A small squeeze of fresh lemon juice in water contains negligible calories and is generally acceptable for fasting. However, avoid pre-made lemonades or adding sugar, which will break the fast.

Yes, adding milk, creamer, or any other calorie-containing additive will break your fast by introducing macronutrients that trigger an insulin response.

While calorie-free, some diet sodas contain artificial sweeteners that can affect insulin levels or increase cravings. For a strict fast, it's best to avoid them.

Plain water is the single best drink for hydration. During longer fasts, mineral water or water with a pinch of salt can help maintain electrolyte balance.

Bone broth contains calories and protein, which means it will technically break a fast. It is typically recommended as a gentle way to break a fast, not for consumption during the fasting window itself.