What Can You Actually Drink During Intermittent Fasting?

So, you’ve decided to start your Intermittent Fasting journey. You’ve chosen your method, planned your eating window, and you’re ready to go. But then, a crucial question pops into your head: “What can I actually drink during my fasting window?”

It’s a simple question with a surprisingly confusing answer. Can you have your morning coffee? Does lemon water count? Will a splash of milk in your tea ruin everything?

This is one of the most common hurdles for beginners. The wrong beverage can accidentally break your fast, kicking your body out of its fat-burning state and undoing your hard work. But don’t worry, we’re here to clear up all the confusion.

This article will give you a complete, straightforward list of what you can—and can’t—drink during your fasting window to ensure you get the best possible results.

The Golden Rule: What Breaks a Fast?

Before we dive into the list, let’s understand the basic rule. In the simplest terms, anything that contains calories will break your fast.

When you consume calories, your body releases insulin to process the energy. The primary goal of intermittent fasting is to keep insulin levels as low as possible for an extended period, which allows your body to switch to burning stored fat for fuel. Even a small number of calories can cause a small insulin spike, technically interrupting the “fasted state.”

If your goal is purely weight loss, a tiny amount of calories (under 10) might not have a significant impact. However, if you are fasting for other benefits like autophagy (cellular cleanup), it’s best to stick to zero-calorie options.

If you’re new to this eating pattern and want to understand the science behind it, you should first read our [The Ultimate Beginner’s Guide to Intermittent Fasting]. It covers everything you need to know.

“Yes!” – The Safe Zone: Drinks That Will NOT Break Your Fast

These are your go-to beverages during your fasting window. You can consume them freely without worrying about breaking your fast.

1. Water

This is the king of all fasting drinks. It’s essential, has zero calories, and is crucial for staying hydrated.

• Plain Water: Still or sparkling, it’s your best friend.
• Why it’s great: Water helps to manage hunger pangs, flush out toxins, and keep your energy levels stable. Staying hydrated is one of the most important parts of a successful fast.
• Pro Tip: Drink a large glass of water as soon as you wake up to kickstart your hydration.

2. Black Coffee

Good news for coffee lovers! Plain, black coffee is perfectly acceptable during a fast.

• What’s allowed: Brewed coffee, Americano, espresso.
• What’s NOT allowed: No sugar, no milk, no cream, no artificial sweeteners. Anything you add to your coffee that contains calories will break your fast.
• Why it’s great: Coffee contains caffeine, which can help to suppress appetite, boost your metabolism, and improve mental focus during your fast.

3. Plain Tea

Like coffee, most types of plain, unsweetened tea are fine to drink while fasting.

• What’s allowed: Green tea, black tea, oolong tea, and herbal teas like peppermint, chamomile, or ginger tea.
• What’s NOT allowed: Again, no sugar, honey, milk, or cream. Also, be cautious of fruity herbal teas that may contain pieces of dried fruit, which can add a small number of calories. Stick to simple, single-ingredient teas to be safe.
• Why it’s great: Green tea, in particular, is rich in antioxidants and has been shown to support fat burning. Herbal teas can be very soothing and help manage cravings.

“Maybe” – The Grey Area: Drinks to Be Cautious With

These drinks contain a very small number of calories or ingredients that might trigger a minimal insulin response. Whether you include them depends on how strict you want to be.

1. Lemon Water

A very popular question. A squeeze of lemon in your water is generally considered acceptable.

• The Details: A whole lemon wedge contains less than 5 calories and a negligible amount of sugar. For most people, this is not enough to cause a significant insulin spike or break the fast.
• The Verdict: Generally okay. It can make water more palatable and provides a bit of Vitamin C. Just don’t overdo it.

2. Apple Cider Vinegar (ACV)

Many people add a splash of ACV to their water in the morning.

• The Details: One tablespoon of ACV has about 3 calories. It’s known to have potential benefits for blood sugar control and satiety.
• The Verdict: Generally okay in small amounts (1-2 teaspoons in a large glass of water). It won’t significantly impact your fast and may even help with hunger.

3. Zero-Calorie Sweeteners

This is a very controversial topic. Sweeteners like Stevia or Erythritol technically have zero calories.

• The Details: While they don’t have calories, some research suggests that the intensely sweet taste can still trigger a small insulin response in some individuals, as the brain anticipates the arrival of sugar. This effect varies greatly from person to person.
• The Verdict: Use with caution. If your main goal is weight loss, they are probably fine. If you are fasting for gut health or autophagy, it’s best to avoid them as they can sometimes affect the gut microbiome.

“No!” – The No-Go Zone: Drinks That WILL Break Your Fast

These drinks contain calories and will definitely break your fast. Avoid them completely during your fasting window.

1. Anything with Sugar, Milk, or Cream

This is the most obvious category.

• Examples: Lattes, cappuccinos, regular soda, sweetened iced tea, energy drinks.
• Why: Sugar and milk (which contains lactose, a sugar) will cause a significant insulin spike, immediately stopping the fat-burning process.

2. Fruit Juice

Even 100% pure fruit juice is a no-go.

• Examples: Orange juice, apple juice.
• Why: Fruit juice is essentially a concentrated dose of sugar (fructose) without any of the fiber from the whole fruit. It will spike your insulin levels just as much as a can of soda.

3. Bone Broth

While incredibly healthy, bone broth is not for your fasting window.

• Why: Bone broth contains protein and a small amount of fat, which means it contains calories. These calories will break your fast. It’s, however, an excellent way to break your fast, as it’s gentle on the stomach.

4. Diet Sodas

This falls into the same “grey area” as artificial sweeteners, but most experts advise against it.

• Why: While they are zero-calorie, the artificial sweeteners (like aspartame) and chemicals in diet sodas can have negative effects on your gut health and may still trigger cravings for sweet things. It’s best to stick to clean, natural beverages.

5. BCAAs (Branched-Chain Amino Acids)

If you work out, you might be tempted to take BCAAs during your fast.

• Why: Amino acids are the building blocks of protein. Consuming them will trigger an insulin response and break your fast. It’s best to take your supplements during your eating window.

Conclusion: Keep It Simple

When you’re in your fasting window, the best strategy is to keep it simple. Sticking to water, black coffee, and plain tea is the most foolproof way to ensure you’re getting all the benefits of your fast.

By understanding which drinks support your goals and which ones hinder them, you can navigate your Intermittent Fasting journey with confidence and achieve the results you’re looking for.