Most fasting questions are really drink questions. Coffee with cream, electrolyte water, diet soda, bone broth—each camp has a confident advocate. Rather than treating every sip as a moral test, it helps to sort drinks by what your schedule actually requires.
The safe default list
For standard intermittent fasting—16:8, 14:10, and similar—the boring answer is usually correct:
- Water — still or plain sparkling, unflavored.
- Black coffee — no sugar, milk, cream, or butter.
- Plain tea — green, black, or herbal without added juice or honey.
These three cover most daily fasts without debate. Our longer reference, what you can drink while fasting, expands on edge cases. Coffee habits get their own page: can you drink coffee while fasting.
Usually fine with label checks
Some drinks sit in a practical gray zone—acceptable for many IF schedules if they are truly zero-calorie and sugar-free:
- Unsweetened electrolyte mixes — sodium, potassium, magnesium without maltodextrin or glucose.
- Diet soda and zero-calorie flavored water — no calories, but sweeteners may affect cravings.
- Lemon or lime squeeze in water — trace calories; heavy juice is different.
- Apple cider vinegar in water — small amounts, negligible calories.
Electrolyte details matter on longer fasts. Read electrolytes during fasting and browse fasting-safe supplements before stocking your pantry. When in doubt, run the drink through Am I Breaking My Fast?
Drinks that break a fast
- Milk, cream, half-and-half, and most coffee shop add-ins.
- Butter coffee, MCT oil, coconut oil—calories marketed as “fasting aids.”
- Protein shakes, collagen, BCAAs, and meal-replacement drinks.
- Juice, soda, alcohol, sweetened tea, and energy drinks.
- Bone broth with meaningful protein or fat (not the same as plain electrolyte water).
- Most sports drinks—sugar is the point of the formula.
These are not forbidden forever—they belong in the eating window. The issue is drinking them during the fast and still calling the fast intact. What breaks a fast covers food and supplements with the same lens.
Artificial sweeteners: technical vs practical
Stevia, sucralose, and similar sweeteners add no calories. Strictly speaking, they may not break a fast. Practically, some people report stronger sweet cravings or gut discomfort when they use them fasted. If diet soda keeps you on schedule without rebound eating later, that is a personal trade-off—not a universal rule.
If sweet drinks lead to overeating at the first meal, the fasting window still failed its purpose. Plan that meal with Fast Window Meal Planner and ideas from best first meals after a fast.
Stricter schedules, stricter drinks
On OMAD or extended fasts, gray-zone drinks carry more weight—a large cream coffee can be a significant fraction of a one-meal day. Common OMAD mistakes often start with “just a little” in the cup. Tighter windows reward black coffee and water as defaults.
Beginners should not negotiate exceptions on day three. Build the habit on intermittent fasting for beginners first; add nuance once 16:8 feels routine.
Sparkling water and flavored options
Plain sparkling water without sweeteners fits the same category as still water. Watch canned drinks labeled “natural flavor” that include juice concentrate or calories. A true zero-calorie seltzer is fine; a sparkling lemonade with sugar is not.
Herbal tea without added honey behaves like water for most schedules. Chai lattes, matcha with milk, and bottled tea drinks almost always belong in the eating window—check the label before assuming they are fasting-safe.
Hydration habits that help
Front-load water in the morning. Do not let coffee replace hydration—dehydration mimics hunger. If you train fasted, sip water before and after; electrolytes may help on sweaty sessions without breaking the fast when chosen carefully.
When the eating window opens, transition to food deliberately. How to break a fast properly and the First Meal Directory beat grabbing whatever is fastest. Avoid refeeding errors in common mistakes when ending a fast.
Where to go next
All fasting tools—including drink checkers and meal planners—live at Tools. New visitors can orient at Start Here. For protein at the first bite after hours of liquids only, see why protein matters when breaking a fast.