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Does a Morning Coffee Break Your Intermittent Fast?

Does a Morning Coffee Break Your Intermittent Fast?

Intermittent fasting certainly isn’t a new idea; the concept of voluntarily not eating or drinking anything but water in order to gain certain benefits — health, religious or otherwise — has been around since ancient times1. While it’s recommended that you talk to a doctor about fasting before you start, it’s widely considered to be an effective dieting option as long as it’s done safely. As such, there isn’t much point in hashing out the benefits of fasting, although there are many, according to U.S. Federal Science.


  • When Does Coffee Break a Fast?
  • Does Tea Break a Fast?
  • Do Artificial Sweeteners Break a Fast?
  • Does Bulletproof Coffee Break an Intermittent Fast?
  • What Does Break a Fast When Intermittent Fasting?
  • However, some people wonder about their daily routines and how much they need to change them during a fast. Specifically, this can include whether or not their daily cup of joe will need to be jettisoned in the hopes of a more effective fast. Still, others claim that it’s possible to drink liquids besides water. So, which is the truth: Does coffee break a fast, or is it ok to continue enjoying that morning caffeine boost?

    Does Coffee Break an Intermittent Fast?

    Black coffee is considered one of the drinks you can safely consume without breaking your fast. This is because it has zero calories and zero carbs, meaning it will not interfere with an intermittent fast. Drinking black coffee in the morning — or throughout your fast — will not interfere with the fat loss benefits of your fast, and it will not take you out of your fasted state like some other beverages that contain carbs or calories.

    Keep in mind, however, that this applies exclusively to black coffee and mostly to those who are fasting for weight loss. There are other times where drinking coffee can potentially cause you to break your fast, depending on why you’re doing it.

    When Does Coffee Break a Fast?

    There are many benefits to fasting, and currently, one of the most popular benefits is autophagy. Autophagy is a process that the body undergoes to clean up proteins that have been damaged or that the body no longer needs. It’s a natural way that the body is able to promote health, and in some cases, anti-aging2. Intermittent fasting has recently been found to be effective at helping the body achieve autophagy3.

    SUCCESS: 25 Nutrients All Intermittent Fasters Should Know About

    However, it’s hard to determine what effect, if any, coffee has on autophagy. While a 2014 study found that coffee can actually help induce autophagy in test mice4, Dr. Akil Palanisamy, MD, author of The Paleovedic Diet: A Complete Program to Burn Fat, Increase Energy, and Reverse Disease, concludes that autophagy can only truly be achieved without taking in any food or drinks aside from water.

    In addition, those who are concerned about their insulin levels and hoping to increase their insulin sensitivity might want to avoid coffee during a fast as well. Acute ingestion of caffeine can reduce one’s insulin sensitivity, although drinking coffee over the long-term can actually increase it5.

    Does Tea Break a Fast?

    Tea is a bit more complicated, as there are many different kinds of tea that can affect your fast in different ways. Green tea, a popular drink among the fasting, should pretty much be ok. On its own, it doesn’t contain any carbs or calories, so it won’t get in the way of losing fat or break your fast6. It also has similar properties to coffee when it comes to interfering with autophagy.

    However, many people drink black tea during a fast, which can be a bit dicey. Though it is certainly healthier for you than soda, as confirmed by the US Food and Drug Administration, certain kinds of black tea can contain just a few calories and/or carbs (usually less than 3 calories and 1 carb, respectively).

    Still, this can potentially stand in the way of the health benefits associated with fasting, so you may want to stick with green tea instead.

    Do Artificial Sweeteners Break a Fast?

    You may be asking yourself if you can’t just make your tea or coffee a little less blah by adding artificial sweeteners. The truth of the matter is there are so many different types of artificial sweeteners available, and Harvard Medical School states we still don’t know exactly what the effects of these sugar substitutes are on our health.

    If you want to add something, though, stevia can be a good option. It is considered one of the best sweeteners to use with the keto diet, it won’t affect your blood sugar severely and it won’t stand in the way of burning fat, although it could potentially make it more difficult to do so.

    Does Bulletproof Coffee Break an Intermittent Fast?

    Bulletproof coffee is a beverage that contains coffee, butter and coconut oil (or MCT oil). People who drink it usually do so to increase their energy and start their day with a healthy, high-fat breakfast that is also easy to ingest. However, bulletproof coffee is not a beverage that will keep you from breaking your fast. It has a lot of calories in it (naturally), so if your goal is to remain on an empty stomach, it’s best to avoid BPC.

    What Does Break a Fast When Intermittent Fasting?

    You probably know that eating food will break your fast. Still, it’s good to remember that certain beverages, even ones that are good for you, can cause the same effect. Some drinks that you’ll want to avoid when fasting include

    • Anything with lots of carbs, sugar or calories
    • Tea or coffee with sugar added
    • Diet soda
    • Bone broth
    • Juices (only effective when on a juice or partial fast)
    • Almond milk
    • Coconut water

    Whether your fasting for 16 hours or you’re doing a more intense 24 hour fast, you’re going to need to remember to drink water, as your body can’t survive without it.

    Still, make sure you avoid the drinks on this list, and you’ll achieve your goal. Remember, too, not to binge on your non-fasting days, as this is unhealthy7. Instead, follow an eating plan that is high in fiber and protein.

    Coffee During Fasting: Yes or No?

    So, now, you may be confused. Should you drink coffee while fasting? Is it worth the potential effects the beverage could have on your fast? The short answer is that yes, black coffee is safe and effective to drink during a fast, and it won’t interfere because it has no calories and no carbs.

    The short answer is that yes, black coffee is safe and effective to drink during a fast, and it won’t interfere because it has no calories and no carbs.

    The long answer, however, is that it’s a good idea to do whatever helps you continue your fast, remain healthy and achieve your goals. Are you worried coffee will interfere with autophagy? At least your body will be able to achieve some autophagy during your fast, which is better than none at all. Concerned that a little stevia will break your fast? If it keeps your spirits up while fasting to have a little bit of sweetener in your coffee, do it!

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    In truth, fasting should be about your personal goals as well as well as about allowing you to take control of your health. If bending the rules just slightly helps you stay on track in the long run, or for a longer period, it’s worth it. So, worry no more and fire up that coffeemaker!

    Citations and Sources

    Additional Resources:

    Patterson R, Laughlin G, Sears D, et al. INTERMITTENT FASTING AND HUMAN METABOLIC HEALTH. J Acad Nutr Diet. 2015;115(8):1203-1212. [PMC]
    Gelino S, Hansen M. Autophagy – An Emerging Anti-Aging Mechanism. J Clin Exp Pathol. 2012;Suppl 4:006. [PMC]
    Moro T, Tinsley G, Bianco A, et al. Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males. J Transl Med. 2016;14:290. [PMC]
    Pietrocola F, Malik S, Mariño G, et al. Coffee induces autophagy in vivo. Cell Cycle. 2014;13(12):1987-1994. [PMC]
    Shi X, Xue W, Liang S, Zhao J, Zhang X. Acute caffeine ingestion reduces insulin sensitivity in healthy subjects: a systematic review and meta-analysis. Nutr J. 2016;15(1):103. [PubMed]
    Templeman I, Thompson D, Gonzalez J, et al. Intermittent fasting, energy balance and associated health outcomes in adults: study protocol for a randomised controlled trial. Trials. 2018;19:86. [PMC]
    Collier R. Intermittent fasting: the science of going without. CMAJ. 2013;185(9):E363-E364. [PMC]
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