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Can You Drink Coffee While Fasting?

Do you need your caffeine fix?

A frequently asked question among the fasting community is whether drinking coffee is off-limits during an intermittent fast. As lots of us rely on our morning coffee to make it through the day, it’s no wonder that caffeine intake is a primary concern for IF dieters.

Perhaps the biggest fear while intermittent fasting is unintentionally breaking your fast, especially with something that, ordinarily, you might take for granted. So, will coffee break your fast? Can you enjoy the odd cup without interrupting your progress?

This article explains whether drinking coffee is acceptable or a no-go.

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Coffee Is Not a Fast-Breaker – So Can You Drink It While Fasting?

Great news—coffee does not break a fast as long as it’s black.

A strict intermittent fast banishes all calories, including calorie-containing drinks. In the strictest terms, any number of calories that pass your lips will technically break a fast. However, certain items with very low or zero calories will not compromise a fast.

Black coffee is one such item. It has so few calories that drinking black coffee will not physically impact your fast. With less than 3 calories in one cup, it isn’t enough to trigger a metabolic response. Even a few cups are unlikely to hinder the health benefits of IF.

Black coffee has no carbs, fat, fiber, or sugar. It contains the smallest amount of protein; otherwise, coffee is void of macronutrients. It does contain some essential micronutrients, including calcium, magnesium, phosphorus, and potassium.

Coffee is also incredibly rich in powerful antioxidants, including polyphenols and hydrocinnamic acids. It’s great for boosting your health because these antioxidants fight harmful free radicals, helping protect your body from diseases like cancer.

The unique properties of coffee have several perks for people practicing intermittent fasting. So, drinking black coffee during the fasting window is perfectly acceptable.

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How Caffeine Affects Fasting in General

The caffeine content of coffee varies based on factors like the coffee beans, the roasting process, and the serving size. Most importantly, the coffee type determines the caffeine quantity in your coffee.

Below, you can see how much caffeine is in popular types of coffee per cup:

  • Brewed: 94.8 mg per cup
  • Instant: 61.6 mg per cup
  • Espresso: 63 mg per single shot

Caffeine is a natural stimulant. Drinking tea, coffee, and other caffeinated beverages increases the activity in your brain and central nervous system. In turn, it makes you feel more awake and alert, helping to combat fatigue and drowsiness.

Due to these effects, caffeine intake can give you an energy boost—a welcome addition to a lengthy fast. Feeling tired and groggy is expected in the initial days of an intermittent fasting schedule as your body is running on less energy than usual.

Consuming caffeine can help you surpass these early symptoms and make your fast more comfortable. Caffeine can also promote appetite control, which is great for curbing hunger pangs while fasting. Intake may also aid fat burning and promote weight loss.

4 Benefits of Coffee While Fasting

Aside from promoting weight loss, drinking coffee can support your fasting journey in other ways. There are many benefits of intermittent fasting, like autophagy and boosting brain health. Interestingly, coffee consumption can enhance these purported benefits.

Below, you can discover 4 health benefits of coffee while intermittent fasting.

1. Increases autophagy

Drinking coffee during the fasting period can activate autophagy.

Autophagy is the body’s natural process of cleaning up cells. It recycles and removes old and damaged cells to create new, healthier cells. Autophagy occurs when your cells are deprived of nutrients, making fasting one of the most effective strategies to induce it.

Coffee can speed up the process due to powerful polyphenols. Many people fast for autophagy as it plays an essential role in human health and protecting against disease.

2. Decreases inflammation

Coffee contains active compounds that have anti-inflammatory effects.

Regular coffee consumption is linked to a reduced risk of health conditions caused by low-grade inflammation. Chronic inflammation is a driving factor in many chronic diseases, including arthritis, cancer, diabetes, and cardiovascular diseases.

Intermittent fasting is already associated with reduced inflammation. Drinking coffee may aid your progress if you are fasting to decrease inflammatory markers, for example, to support chronic pain conditions.

3. Can keep your brain healthy

Coffee is great for your brain health because it improves cognitive function by reorganizing brain functional connectivity.

It is linked to improved attention span, better memory, and faster reaction times in cognitive tasks, which is useful when you’re running on no food.

Moreover, increased coffee intake may slow mental decline. Therefore, coffee may serve as a protective measure against brain diseases, such as Alzheimer’s disease.

4. Gives you energy and keeps you alert

The caffeine content blocks adenosine receptors in the brain—a sleep-promoting chemical. Adenosine builds up throughout the day, and you begin to feel sleepy as it gradually increases. As caffeine blocks these receptors, you remain more awake and alert.

Consuming coffee in the morning is a widespread habit because it gives you an energy boost. Drinking coffee right at the beginning of your intermittent fast will increase your energy levels and fuel your body so that you can power through to your eating window.

Be Prepared for These Side Effects

While coffee boasts impressive health benefits, too much coffee has adverse effects. Finding a balance between reaping the perks and going overboard is crucial. It’s best to monitor your intake, especially if you are not a regular coffee drinker.

Before you pour that extra cup, consider the following effects:

Excessive coffee consumption can increase insulin levels

Your insulin levels may increase if you have too many cups of coffee.

During a fast, your insulin levels drop. This allows your body to move into fat-burning mode as it starts burning body fat. When your insulin levels rise, usually with the reintroduction of food and calories, you risk breaking your fast as the fat-burning process shuts down.

Coffee can affect your sleep quality

Coffee is a stimulant that can disrupt your sleep patterns. Research suggests caffeine just 6 hours before bed can significantly impair sleep. It’s best to avoid drinking coffee in the late afternoon and evening to maintain good sleep hygiene.

Poor sleep can negatively impact your intermittent fasting journey and your overall well-being. It can also affect weight loss interventions, as sleep restriction increases hunger and appetite. This makes it difficult to sustain your willpower during a fast.

Coffee can cause jitters and a drop in energy levels

Caffeine stimulates the central nervous system, and high doses can cause jitters, rapid heart rate, high blood pressure, and anxiety. That’s because caffeine generates the release of the adrenaline hormone, activating your body’s fight-or-flight response.

While caffeine can make you feel energized, it’s common to experience a caffeine crash that leaves you with fatigue once the effects wear off. This can hinder your intermittent fasting progress as you might feel tired and less able to continue with food abstinence.

Tips on How to Enjoy Your Coffee Without the Negative Side Effects

If you want to drink coffee while intermittent fasting, you need to know how to avoid the negative side effects of caffeine. You can take a few preventative measures before overindulging in the world’s favorite beverage.

Here are 4 top tips to try:

Stay hydrated

While you can’t flush caffeine from your system, keeping yourself hydrated can decrease the effects. Sometimes dehydration enhances some of the effects, like headaches and jitters. Drinking plenty of water will help mitigate these nasty symptoms.

To stay hydrated, you could try drinking a glass of water with every cup of coffee you have. You should aim to drink fluids regularly throughout the day. The general recommendation for daily water intake is 3.7 liters for men and 2.7 liters for women.

Keep your coffee intake moderate

Moderation is vital when drinking tea, coffee, and other caffeinated drinks. The FDA recommends consuming no more than 400 milligrams of caffeine per day (about 4 cups of coffee). This is considered a safe dose to prevent adverse side effects.

People metabolize coffee differently. Some might tolerate more, while others need less caffeine. You can moderate your intake by keeping track of how many cups you have, allocating specific times of the day to drink coffee, and limiting daily intake.

Keep intervals between your cups

It can be easy to drink copious amounts of coffee when you’re feeling tired. However, you need to control your coffee intake to reduce the chances of side effects. Organizing a coffee break can help keep intervals between your cups to prevent overdose.

Try decaffeinated coffee

Contrary to popular belief, decaffeinated coffee still contains a small amount of caffeine. A cup of decaffeinated coffee has 2.37 milligrams of caffeine. However, swapping a strong coffee for decaf can give you many of the same benefits without the side effects.

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How to Make Your Coffee Tastier Without Breaking the Fast

People who drink black coffee appreciate its rich, aromatic flavor. However, those who ordinarily drink milky, sugary coffee might find black coffee bitter. It’s not for everybody, but fortunately, there are some ways to alter the taste without breaking your fast.

You can try adding the following ingredients:


Spices add flavor to water, tea, and coffee. They are very low in calories and macronutrients. The calorie count is negligible as you only use a small amount, typically no more than a dash. Although low in macros, spices are nutritional powerhouses.

Some of the best spices to upgrade your coffee and boost your health are:

  • Cardamon
  • Cinnamon
  • Ginger
  • Turmeric

Zero-calorie sweeteners (keep it natural)

If you want to sweeten your coffee without using sugar, natural sweeteners with zero calories are the best choice. Natural sweeteners, like stevia and monk fruit, will not negatively affect your blood glucose levels or activate your digestive system.

Stevia has no calories or carbohydrates. You can add stevia to your coffee to relieve sugar cravings without breaking your fast. Monk fruit is another natural sweetener that won’t raise your blood sugar levels. It contains no calories, carbs, fat, or sugar.

It’s best to avoid artificial sweeteners during intermittent fasting as they can spike your blood sugar and break your fast. Examples include sucralose and aspartame.

Almond milk

Almond milk provides a nutty flavor to coffee. As it does contain calories, you must only consume it in small quantities. If you follow a modified fasting approach, the general rule is that you can remain in the fasted state if your caloric intake is under 50.

One cup of unsweetened almond milk has just under 40 calories. If you include the few calories from your coffee, you can consume up to a cup without exceeding your calorie budget. Add too much, however, and you will quickly end your fast.

Coconut oil

Adding a little coconut oil to your coffee will technically break your fast, but it won’t completely sabotage the benefits of intermittent fasting. However, it is very high in calories, so you should only use a small amount.

Coconut oil contains healthy fats and medium-chain triglycerides that stimulate ketone production. If you are fasting for ketosis—the process where the body breaks down fats for energy— it is a keto-friendly option that can help you reach your weight loss goals.


The high-fat content boosts your energy levels and promotes satiety. Many people add coconut or MCT oil to bulletproof coffee alongside grass-fed butter.

DoFasting Makes Fasting Easy

You now know that black coffee is safe to drink while fasting, but you might still have other intermittent fasting questions. If so, you can learn everything you need to know from DoFasting.

The DoFasting app is a great resource, whether you’re fasting for weight loss, gut rest, metabolic health, or improved insulin sensitivity. It includes all the tools you need while practicing intermittent fasting to improve your overall health, and it’s all in one place.

Educational content, workout routines, thousands of recipes, and different fasting modes allow you to get the most from your chosen plan. It doesn’t matter if you’re a beginner or an expert, the DoFasting app will keep you motivated and always on track.

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Can You Drink Coffee While Fasting: The Key Takeaways

You can absolutely drink coffee while intermittent fasting. The only catch is that it must be black coffee, free from ingredients such as milk, cream, and sugar that will break your fast. Save your flavored coffee and high-calorie additives to enjoy in the eating window.

A cup of this antioxidant-rich, virtually calorie-free drink in your fasting window has multiple perks.


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This is an evidence-based article that includes scientific citations. DoFasting’s professional writers and editors prepared the content, which a team of medical experts verified to be accurate.

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