What Can You Drink While Fasting? A Simple Beginner’s Guide

Fasting means no food. But what about drinks? Most beginners don’t know which beverages keep them in a fasted state. Johns Hopkins Medicine emphasizes that understanding what to drink during fasting is essential for success. One wrong choice stops fat burning and wastes hours of effort.

This guide covers which drinks maintain a fasted state, what actually breaks a fast, how to stay hydrated without ruining progress, and clear rules for beverage choices.

What Breaks a Fast?

Understanding what breaks a fast is simple. Johns Hopkins Medicine defines fasting as abstaining from food during specific periods. A fast breaks when calories trigger an insulin response. The body switches from burning glucose to burning fat during fasting.

Three things break fast: sugar and carbohydrates, protein, and fat in significant amounts. Most experts agree that keeping intake below 50 calories may preserve some fasting benefits. Strict fasting means zero calories.

Some protocols like the 5:2 method allow 500 calories on fasting days. These modified approaches still provide benefits but aren’t pure fasts.

Examples:

Orange juice: 110 calories, high sugar = breaks fast
Milk: Contains lactose and protein = breaks fast
Black coffee: 0-5 calories = doesn’t break fast

With this rule established, here are the drinks that work.

Water: The Primary Fasting Beverage

Water is the foundation. Water is the best choice during fasting as per many scientific researches. Zero calories means zero insulin response. Research shows drinking water boosts metabolism and supports weight loss.

How much water does someone need? The standard formula is body weight in pounds divided by two equal ounces per day. A person weighing 160 pounds needs 80 ounces daily.

Approximately 20-30% of water intake normally comes from food. Fasting requires more deliberate hydration since food isn’t providing that portion.

Acceptable water types include:

Plain water (hot, cold, or room temperature)
Carbonated water without added sugar
Mineral water
Water with lemon, cucumber, or mint for natural flavor

Safe options: La Croix, plain seltzer, Perrier

Avoid: Vitamin Water, flavored waters with sweeteners, enhanced waters

Those tracking their fasting can check our fasting tracker to monitor hydration levels throughout fasting windows.

Coffee and tea offer additional options.

Coffee and Tea During Fasting

Coffee and tea are fasting-friendly beverages. Research confirms black coffee doesn’t break fast. It contains 0-5 calories per cup.

Research published in the DeGruyter Brill shows caffeine may increase metabolism. Black coffee also helps suppress appetite during fasting periods. However, some research warns against excessive consumption due to potential jitters.

What makes coffee break a fast:

Milk (contains protein and fat)
Cream (contains fat and calories)
Sugar or honey
Flavored syrups

Each of these additions provides calories and triggers an insulin response.

Tea works the same way. Black, green, and herbal teas are allowed according to Johns Hopkins Medicine. They must be unsweetened with no milk or cream added. All varieties work: black, green, white, oolong, and herbal.

The gray area: Adding creamer under 50 calories may not completely stop ketosis but affects fasting benefits. Strict fasting means nothing added. For weight loss goals, skip all additions.

Allowed: Black coffee, espresso, green tea, peppermint tea, chamomile

Questionable: Coffee with small cream splash

Breaks fast: Lattes, cappuccinos, sweet tea, chai with milk

Our AI assistant can provide guidance on coffee and tea additions based on specific fasting goals.

Artificial sweeteners present complications.

Artificial Sweeteners and Fasting

Artificial sweeteners complicate fasting. Zero calories doesn’t guarantee fasting safety. Some artificial sweeteners may trigger insulin responses even without calories. Individual responses vary significantly.

Safer options include:

Stevia generally doesn’t affect blood sugar levels. Research shows minimal insulin response in most people.

Monk fruit has a similar profile to stevia. It provides sweetness without metabolic impact.

Saccharin (Sweet’N Low): Shows minimal impact on blood sugar and insulin levels.

Questionable options require caution:

Splenda (sucralose): May trigger insulin release in some individuals. Regular sucralose consumption can affect glucose metabolism.

Aspartame: Research shows mixed results. Some studies indicate insulin effects while others show none.

Sugar alcohols: Options like xylitol contain over 2 calories per gram. Higher intake can raise glucose and insulin levels.

The hunger effect matters. Sweet tastes increase hunger ratings even without calories. Artificial sweeteners may make fasting more difficult by strengthening cravings.

The safest approach: Avoid all sweeteners during fasting. Those who choose sweeteners should use stevia or monk fruit sparingly.

Other beverages have specific considerations.

Apple Cider Vinegar, Bone Broth, and Electrolytes

Several special-case beverages require clarification.

Apple Cider Vinegar

Cleveland Clinic states that diluting 1-2 tablespoons in water doesn’t break a fast. It may support weight loss and help lower blood sugar.

Apple cider vinegar must be diluted but never consumed straight. Mayo Clinic notes undiluted apple cider vinegar can irritate the throat. Mix one to two tablespoons in a full glass of water.

Bone Broth

Bone broth contains vitamins and nutrients but includes calories. This breaks a strict fast. Some fasting protocols permit bone broth for electrolytes and hunger management. It may not stop ketosis but does provide calories that trigger some metabolic responses.

Strict fasters avoid bone broth. Those doing modified fasting may include it.

Electrolyte Water

Electrolyte water is safe when sugar-free and calorie-free. It helps prevent electrolyte imbalance during fasting. Plain water with a pinch of Himalayan salt provides the same benefit.

Commercial electrolyte supplements work if they contain zero sugar and zero calories. Check labels carefully.

Beverages to Avoid Completely

Fruit juices contain high sugar and spike blood glucose. Even 100% fruit juice breaks fast immediately.

Soda and energy drinks contain sugar or chemicals that disrupt metabolism. Regular versions obviously break fasts. Diet versions technically don’t break a fast but may trigger cravings.

Milk and dairy products contain lactose (sugar) and protein. Both break a fast by triggering insulin and digestive processes.

Here’s a simple reference guide.

Fasting Beverage Guidelines

This quick reference simplifies beverage choices.

Always Safe:

Plain water (hot, cold, or room temperature)
Sparkling water (unsweetened)
Black coffee (no additions)
Plain tea (any variety, unsweetened)
Water with fresh lemon or cucumber

Use Sparingly:

Stevia or monk fruit (minimal amounts)
Apple cider vinegar (diluted in water)
Electrolyte supplements (zero sugar)

Avoid Completely:

Drinks containing sugar
Milk, cream, or dairy
Fruit juice (including 100% juice)
Smoothies
Protein shakes
Alcohol
Regular soda
Sports drinks with sugar
Flavored coffee drinks
Coconut water

These guidelines cover most situations. Beginners should start with water, black coffee, and plain tea. Those needing specific guidance can check our fasting tracker or use our AI assistant for questions about particular beverages.

Simple Rules for Success

The answer to what someone can drink while fasting is straightforward. Water, black coffee, and plain tea are always safe. These beverages contain zero or minimal calories and don’t trigger insulin responses.

Johns Hopkins Medicine emphasizes staying hydrated during fasting periods. Proper beverage choices support fasting goals rather than undermining them. Dehydration causes fatigue, headaches, and makes fasting harder than necessary.

For beginners, three rules simplify everything:

Rule 1: Drink plenty of water. Most people need half their body weight in ounces daily. Fasting requires even more attention to hydration.

Rule 2: Keep coffee and tea plain. No milk, cream, sugar, or syrups. These additions break a fast by providing calories and triggering metabolic responses.

Rule 3: When uncertain, choose water. It’s impossible to break a fast with plain water.

New to fasting? Read our article on common intermittent fasting mistakes and beginner guidelines to start your journey correctly.

Advanced fasters can experiment with apple cider vinegar, artificial sweeteners, or electrolyte supplements. Beginners should master the basics first. Water, black coffee, and plain tea provide everything needed during fasting windows.

Knowing what to drink while fasting removes uncertainty. This makes the process easier to follow and increases chances of success. Start with the basics, stay hydrated, and the rest falls into place.