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Intermittent Fasting and Caffeine

Intermittent Fasting and Caffeine

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Updated 2/1/2022

Intermittent Fasting – Is Caffeine Okay to Have?

Whether you’re fasting to lose weight, relieve gut issues, or improve your overall health, you know how important it is to follow the rules of intermittent fasting if you want to see good results. But if you’re a coffee drinker, you might be wondering how caffeine plays into the grand scheme of things. Is it safe to drink? Will it break a fast? Keep reading to learn the answers to these questions and more.

Probably the biggest concern you have about drinking coffee while intermittent fasting is whether or not it will break you fast. You know that the drink itself doesn’t have many calories— so long as you’re drinking black coffee — but what about the caffeine?

Before we dig too deeply into whether you should be drinking coffee during IF, let’s make sure we’re on the same page about what intermittent fasting means.

What Exactly is Intermittent Fasting (IF)?

Intermittent fasting is a method of promoting weight loss, increasing energy, warding off certain ailments, and increasing one’s general health and longevity.

IF is generally not strict on what foods to eat or not to eat, but rather it focuses instead on when to eat or not eat — it involves alternating cycles of eating and fasting to improve health.

During periods when you’re not eating, you shouldn’t be eating anything at all. You can, however, drink unlimited water as it has no calories and has no chance of breaking your fast. But what about other drinks, namely caffeinated beverages like coffee, tea, diet soda, and energy drinks?

Will Drinking Coffee Break a Fast?

If you’re a coffee lover, you can do a little jump for joy: Black coffee with no additives will not break your fast.

Each cup of plain coffee contains just 5 calories, so it’s well below the generally accepted 50-calorie limit necessary to break a fast. At this rate, you can actually enjoy multiple cups without too much guilt (just don’t over do it — more on that below).

However, keep in mind that “without additives” is a very important distinction — not all coffees are created equal.

Safe Coffees for a Fasting Window

  • Black coffee: Straight coffee with no additives does not contain enough calories to break a fast. However, keep an eye on your consumption: Drinking 10 cups per day will put you right at the 50-calorie limit.
  • Cold brew: Coffee that’s been cold-brewed may have more caffeine than drip coffee, but it has just about the same number of calories, so it’s also safe to drink when fasting.
  • Espresso: Made by putting coffee grounds under extreme pressure, traditional espresso has no additives like milk and sugar, so it’s also okay to drink while fasting.
  • Americano: An Americano is just like an espresso, just with more hot water added after brewing. So long as you take it traditional, it’s fine for fasting.

Safe Coffees for a Fasting Window… to an Extent

  • Coffee with cream: As you need to stay under 50 calories so as not to break your fast, coffee with cream may be okay, depending on how much cream you take and how many cups you intend to drink. One tablespoon of milk has 6 calories, while the same amount of coffee creamer has 20 calories, so keep that in mind when calorie counting.
  • Coffee with sugar: As with cream, you may be able to add some sugar to your coffee without breaking your fast, depending on how heavy-handed you are. One teaspoon of sugar contains 16 calories, while one tablespoon has 48 calories.

Coffees to Avoid During Your Fasting Period

  • Coffee with cream and sugar: Unless you plan to drink just one cup of coffee per day, adding cream and sugar to your brew is enough to knock you out of ketosis.
  • Coffee with heavy cream: As heavy cream contains 51 calories per tablespoon, it’s just too much to consume while fasting.
  • Bulletproof coffee: Containing a dose of healthy fat like coconut oil and up to 300 calories per cup, bulletproof coffee is popular among those following a ketogenic diet. However, it’s not suitable during your fasting period.
  • Cappuccino: Containing equal parts of coffee, milk, and milk foam, a single serving of cappuccino is enough to break your fast.
  • Latte: Lattes contain even more milk than cappuccino, so they’re also off-limits.
  • Mocha: Mochas are made with coffee, milk, and chocolate, and they can contain up to 500 calories per serving, so stay away from them if you don’t want to break your fast.

White ceramic coffee mug filled with black liquid

While water should be the main drink of choice when fasting, opting for black coffee is an excellent choice, too. You aren’t cheating or breaking any rules. Intermittent fasting and coffee can actually enhance your fasting experience. Your body will not be taken out of ketosis by drinking black coffee. The caffeine in coffee may also speed up your metabolism.

As fasting is, in part, about weight loss, the boost in metabolism is certainly a plus. What’s another cool aspect of enjoying black coffee while taking part in intermittent fasting though? It can also help stave off hunger! This is helpful for those just trying intermittent fasting out for the first time and who may be having some trouble resisting the urge to break their fast. With black coffee you are speeding up your slim down process and also keeping your appetite at bay.

But there are some tips to remember when enjoying coffee while intermittent fasting. First off, because you will be drinking on an empty stomach most of the time, the caffeine will enter your blood stream much faster than if you were to enjoy coffee during breakfast or after lunch. This may lead to jitters and anxiousness. And as mentioned before, as a general rule of thumb take your coffee black to be on the safe side. For certain intermittent fasting methods enjoying coffee with just a small dollop or splash of cream or milk is okay, as long as it is under a certain amount of calories. Brewed and filtered coffee, cold and Dutch brew, espresso and Americano are all great options to have on your fasting coffee menu.

Will Drinking Tea Break a Fast?

True teas are those that come from the camellia sinensis plant. There are many varieties, including green tea, black tea, and pu’erh tea, and they all contain caffeine.

Those teas that do not come from camellia sinensis are known as herbal teas. They’re made from the bark, flowers, leaves, roots, and seeds of other plants, such as chamomile and peppermint, and they do not naturally contain caffeine.

Depending on who you ask, it’s estimated that there may be as many as 20,000 different tea varieties throughout the world. All you need to know is that so long as you drink natural tea without any additives, you won’t break your fast. The best way to enjoy tea is to brew it yourself by brewing loose leaf tea or tea bags that are unsweetened.

Here are some of our favorite teas — all of which are safe to consume while fasting:

  • Ceylon
  • Earl Grey
  • English Breakfast
  • Ginger tea
  • Lapsang Souchong
  • Matcha
  • Oolong tea
  • Rooibos

Not only are teas safe to drink while fasting, they also offer loads of health benefits. For example, many teas contain tons of antioxidants that help fight off free radicals and protect the body from oxidative stress.

Teas like green and black, in particular, contain catechins. They help the body detox by activating the body’s autophagy process.

True teas also possess another special amino acid, L-theanine — it’s what gives green tea that calming and relaxing effect. While fasting, caffeine may cause you to experience anxiety or jitters since you’re drinking on an empty stomach, but the L-theanine will combat these negative effects and help you stay mellow.

Teas to Avoid While Fasting

As is the case with coffee, most teas are safe so long as they don’t contain any additives. The more ingredients you add to tea, the faster the calories add up.

Avoid bottled, flavored, or sweetened teas as these may have sugars, artificial flavors, and excessive calories. As with coffee, you can add cream or milk to your tea, but you have to watch your caloric intake carefully.

If you’re new to drinking tea, we recommend sticking with just the leaves or herbs and some hot water. You can also cold brew your tea. It’s refreshing and yields tea that’s less bitter, astringent, and caffeinated.

White and red ceramic mug filled with tea


Will Drinking Energy Drinks Break a Fast?

The same discussion surrounding diet soda also spills into the world of diet energy drinks. Though many varieties contain very few calories or are calorie free, there’s debate as to whether the fake sweetness can trick your brain into triggering an insulin response.

An added warning about energy drinks is that some varieties contain much more caffeine than similar servings of coffee or tea. Keep reading to learn more about the possible risks of consuming too much caffeine.

energy drink and intermittent fasting

How Caffeine Affect Fasts

Drinking beverages that contain caffeine is fine for intermittent fasting as a whole. But if you’re fasting to take advantage of a particular health benefit, it’s important to know how caffeine intake may affect those efforts, beyond just breaking a fast.

Fasting for Weight Loss

If you’re fasting to lose weight, you’ll be happy to know that reasonable consumption of caffeine will have no negative effects on your weight loss efforts.

Fasting for Gut Health

The acid in coffee won’t break a fast, but it will activate digestive activity, so if you’re fasting for gut rest, you’ll want to avoid it.

Fasting for Blood Sugar

Fasting can be a way to improve blood sugar levels and overall metabolic health. Drinking coffee won’t affect these benefits, so long as you omit the cream and sugar.

Fasting for Longevity

If you’re fasting to improve longevity, you’ll be pleased to learn that coffee is just fine. Some studies show that the caffeine in drinks like coffee actually reduce inflammation in most people. It can also improve brain health by increasing alertness, helping with concentration, and stabilizing your mood.

Benefits of Caffeine While Intermittent Fasting

Your fast will stay intake when you drink coffee, but pouring that brew can also offer some more benefits. Here’s what caffeine might do when you take a tea or coffee break:

  • Boosts metabolism: The small boost you get won’t cause the pounds to melt off, but it will definitely help you on your weight loss journey.
  • Encourages autophagy: In combination with fasting, caffeine can speed up cell turnover.
  • Improves insulin sensitivity: Caffeine and fasting can work together to combat insulin resistance. Just note that some studies show that excessive coffee consumption (13 cups or more per day) actually causes a short-term increase in insulin levels.
  • Promotes ketosis: Some studies have shown that caffeine intake can stimulate the production of ketones.
  • Reduces hunger pangs: Hot coffee, in particular, can help you feel as if you’ve had something to eat, helping to reduce hunger pangs.
  • Reduces inflammation: Fasting has been shown to reduce a body’s inflammatory response, and many studies show that caffeine does the same thing.

Risks of Caffeine While Intermittent Fasting

Regular coffee consumption isn’t going to break your fast so long as you stay away from additives, but it can affect you in other ways.

Drinking coffee and other caffeinated drinks on an empty stomach can raise your blood pressure. This isn’t a huge concern if you’re healthy, but it can be quite problematic for those who already suffer from high blood pressure.

You may be tempted to keep the coffee train coming now that you know it won’t break a fast, but excessive coffee consumption can trigger some other unpleasant side effects. Drinking more than 5 cups per day can cause anxiety, poor sleep, restlessness, stomach upset (due to the high acidity), and withdrawals if you don’t get you next fix soon enough.


Can I drink coffee while intermittent fasting?

Yes, you can drink coffee without fear of breaking a fast — so long as you skip additives like milk, cream, and sugar, all of which can add calories that will knock you out of ketosis.

Can caffeine make intermittent fasting easier?

Yes, caffeine can make fasting easier by warding off hunger and stabilizing your mood. Just don’t overdo it — too much caffeine can actually have the opposite affect by causing anxiety, tummy troubles, and withdrawal symptoms like headaches.

Should I drink coffee while fasting?

Only you can decide whether you should drink coffee while fasting. Caffeine has its health benefits, but there are also some drawbacks. Having a couple of cups of coffee or tea can speed up your metabolism and make you feel good, but if you have too much, you could trigger issues with insulin sensitivity and difficulty sleeping.

What can I put in my coffee that won’t break my fast?

If you’re fasting for weight loss, most low or low-calorie artificial sweeteners won’t break your fast — just beware that they can cause you to crave regular sugar. You can also add spices like cinnamon, unsweetened cocoa, and nutmeg for a guilt-free dash of flavor.

What else can I drink that won’t break my fast?

If you’re wondering what to drink while fasting, we want to say it loud and clear: Drink water! Plain is best, but if you’d like a little flavor, you can add a squirt of lemon juice or some chopped fruit (just don’t eat the fruit). Watch out for green juices; they may seem like healthy, water-like alternatives, but they can be loaded with 150 calories or more per serving.

Wrapping Up

When it comes to intermittent fasting, coffee and tea are certainly okay and even encouraged — just watch out for those additives. Caffeine from these sources can help amplify the effects of your fast, help stave off hunger, and keep your energy up in lieu food. They can also speed up your digestion and metabolism to keep you feeling good.

For those interested in trying intermittent fasting for the first time, or more experienced fasters who have been wondering about these beverages for a while now, feel free to brew some Earl Grey or to grab a shot of espresso during your fasting periods.

Just be sure to also consume plenty of water during your fast periods and keep your caffeine intake within a reasonable to avoid anxiousness, jitters, and other side effects. Otherwise, these beverages are great additions to an intermittent fasting regimen.