Does Coffee Break a Fast?

Coffee Fast InlineThis has got to be one of the most frequent questions I see: “Does coffee break a fast?”

Let’s answer.

To begin with, I’ll make the case that you shouldn’t worry too much about this stuff. That you’re even willing and able to go without a meal or snack for 12-24 hours places you in rarefied company. That’s 95th percentile stuff. You’re ahead of the game simply by being open to the idea of not eating every hour. Take heart in that. Some coffee with cream midway through doesn’t take away from what you’re accomplishing.

But I know you guys, and I know you love the minutiae. I know it because I love it, too. It’s fun, even if it gets us into trouble sometimes. So let’s dig right in.

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First, does black coffee break a fast?

Put another way.. Does coffee interfere with the benefits we’re seeking from a fast? Depends on the benefits you’re seeking (and what you put in the coffee).

Let’s look at some of the most common benefits first and if/how coffee affects them.

Common Benefits of Fasting: Does Coffee Help Ketosis, Fat Burning, and Insulin Sensitivity?

Coffee and Ketosis

Fasting is a quick and easy (or simple) way to get into ketosis. You have little choice in the matter. Since you’re not eating anything, and your body requires energy, you break down body fat for energy. And because you’ve only got fat “coming in,” you’ll quickly start generating ketone bodies. If coffee stops ketosis, it’s probably breaking the fast.

A recent study found that taking caffeine acutely upregulates ketosis in humans.

Coffee and Fat Burning

Fat-burning is another important aspect of fasting. Since we’ve already shown that coffee increases ketosis, I think it’s pretty obvious that coffee also increases fat mobilization and burning.

Coffee and Insulin Sensitivity

Over the long term, fasting is an effective way to improve insulin sensitivity and glucose tolerance. Most things that make you better at burning fat and expending, rather than storing, energy—like exercise, low-carb diets, weight loss in general—tend to improve insulin sensitivity over time. But the sometimes counterintuitive piece to all this is that in the short term, fasting can reduce insulin sensitivity. This is a physiological measure the body takes to preserve what little glucose remains for the brain. All the other tissues become insulin resistant so that the parts of the brain that can’t run on ketones and require glucose get enough of the latter to function.

Coffee has a similar effect. Acutely, it reduces insulin sensitivity and glucose tolerance (so don’t eat pastries with your coffee). Over the long term, it improves insulin sensitivity and glucose tolerance; many studies find that the more coffee you drink, the lower your risk of type 2 diabetes.

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Does Coffee Affect Autophagy?

Cellular cleanup. Pruning. Entropy dictates that all things are constantly speeding toward disorder. Things fall apart, in other words. That applies to our cells and the tissues they comprise, too. But because we are biological beings rather than inert objects, we can respond to and resist the descent into disorder. Autophagy is one of the ways in which we keep our cells healthy and maintained, pruned, and trimmed of damaged bits. Fasting is one of the best ways to induce autophagy. It’s one of fasting’s major selling points. If coffee destroys autophagy, that’d be a big mark against coffee and a sure sign it’s breaking the fast.

Good thing coffee doesn’t appear to hamper autophagy. At least in mice, both caffeinated and decaffeinated coffee induce autophagy in the liver, muscle tissue, and heart.

Does Coffee Inhibit AMPK?

Adenosine monophosphate-activated protein kinase, or AMPK, is an enzyme that inhibits fat storage and promotes fat burning. It activates antioxidant networks, triggers autophagy, and promotes mitochondrial biogenesis. A major benefit of fasting is that it causes a big uptick in AMPK activation. Other things do, too, like exercise, basic calorie restriction, and any situation where energy is being deprived or expended, but fasting is one of the more reliable paths.

Luckily, coffee doesn’t seem to inhibit AMPK. Caffeine improves endothelial repair via AMPK. Even chlorogenic acid, another coffee component, triggers AMPK.

Okay, so black coffee doesn’t seem to break the fast in any meaningful sense. What about all the things people like to add to coffee?

Common Additions to Coffee: Does Coffee With Milk and Sweetener Break a Fast?

Coffee With Butter/MCT Oil/Coconut Oil

Does coffee with pure fat break a fast? Technically, it breaks the fast. You’re ingesting calories (depending on how much fat you add, it could be a significant number of calories), and calories break the fast. But pure fat has little to no effect on insulin, blood glucose, or any of the other measurements that indicate a “broken fast.”

You won’t burn as much body fat. You’ll still burn plenty of body fat.

It will help you fast longer. Adding a little fat to your coffee can make fasting more tolerable. If you can only manage 12 hours on black coffee but a couple teaspoons of coconut oil help you go 24, the coconut oil might be a good addition.

It shouldn’t affect autophagy. Protein ingestion interrupts autophagy. Butter has a tiny amount of protein that shouldn’t interfere.

Coffee With Heavy Cream

An ounce of cream has almost a gram each of carbohydrate (lactose) and protein. That. Some cream in your coffee won’t affect your fat burning very much, but it probably will inhibit some autophagy.

That said, remember that ketogenic diets increase autophagy too, and those definitely include food. This is all a matter of degree. It’s not a binary on-off switch. Less autophagy isn’t zero autophagy.

Coffee With Almond/Other Nut Milk

As long as you’re avoiding the sweetened versions, or the ones that come fortified with extra protein, and you’re not adding a half cup at a time, a little nut milk won’t make a big difference. There is very little of anything in most nut milks.

Coffee With Cinnamon/Cocoa/Nutmeg

Cinnamon is fine. It tends to reduce insulin resistance, especially the kind you get after a bad night’s sleep.

Cocoa powder is okay, but watch the amount. It’s a “whole legume” powder, so it has carbs, protein, and fat. Anything more than a teaspoon will overdo it. If you add cocoa, use defatted cocoa powder. Adding too much of the cocoa powder with fat included will reduce the effects of fasting.

Nutmeg is fine, too. Just avoid psychotropic doses.

Coffee With Stevia

Does coffee with sweetener break a fast?

When you eat it with a snack containing 290 calories, stevia lowers glucose and insulin levels. I see no mechanism by which stevia could make the situation worse without a meal.

Coffee With Monkfruit Extract

Monkfruit extract has an effect similar to stevia. It’s fine.

Coffee With Artificial Sweeteners

There’s no good evidence they’ll impair the metabolic response to fasting, but there are other unwanted effects you should want to avoid.

Coffee With Collagen

As much as I love (and sell) collagen, it is pure protein, and protein tends to activate mTOR and inhibit autophagy. This means that collagen in your coffee during a fast is probably fine for fat-burning (and may suppress appetite, helping you fast for longer) but will reduce the benefits of autophagy.

How to Order Coffee At a Coffee Shop While Fasting

Order black coffee: drip, pour-overs, espressos, Americanos. That’s the most surefire way to maintain the fast.

Don’t use the “cream.” Ask for heavy cream. The “cream” coffee shops tend to set out for customer use is actually half-and-half: half milk, half cream. That gives it a significant protein and carb load that will inhibit the effects of the fast. Instead, if you absolutely need something to add to your coffee, ask the staff for heavy cream.

Avoid nut milks. Coffee places often use sweetened nut milks, and they use entirely too much of it. An “almond milk latte” will have around 8 ounces of almond milk, far too much for your fast (even if it’s unsweetened).

That’s about it for coffee and fasting. If you have any further questions, don’t hesitate to ask down below. I’ll get to as many as I can in a future post.

Thanks for reading, take care, and enjoy your coffee!

To read more about coffee, visit:

To read more about fasting, check out:


About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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165 thoughts on “Does Coffee Break a Fast?”

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  1. Seems to me a great way to get the best of all worlds might look like: eggs and veggie for breakfast a couple times a week, perhaps a bulletproof coffee once or twice a week, and straight up black coffee a few times. Unless you are really “hard-core” and just fast everyday. I have a super active job so multiple times a week I can really feel I need a breakfast to be at my best.

    1. That’s the rub…all these demanding jobs that need fuel! If your body is asking, there’s a reason.

  2. Thanks Mark, this post was *really* helpful. I’ve been primal for 6 years and am usually in the 100-150g carb range. I’ve also been intermittent fasting (12-15 hours fasts daily, usually broken by 7-8AM) for over a year now. I just started keto last week. I’m on day 6 and have confirmed that I’m doing it right (using ketostix for now). Every day since day 2, I’ve tested in the high range for urine ketones in the afternoon, but I happened to do a 6-mile run yesterday afternoon (keeping my heart rate less than 130 (I’m 43) and feeling energetic the whole time). Immediately afterward, my ketones registered as “trace” despite eating the same way as I had on the all the other days that I had registered high amounts of ketones. This run also put me into a complete torpor for the rest of the day, no energy and totally sluggish brain (muscles are apparently outcompeting the brain for ketones in the early stages of keto-adaptation as you indicated in your book). I ate after the run (two tablespoons of Coconut Manna and a half tablespoon of peanut butter) and two hours later I was back to “moderate” urine ketone levels. I’m trying to work out what the heck is happening with regard to energy use by my muscles during the run. Were they using mostly glycogen or ketones? (As expected, it doesn’t seem like fat oxidation is all that efficient yet.) Are the muscles in general more adept at using ketones than the rest of the tissues? That is, why is it that only exercise seems to deplete them right now? And if I *do* use all the glycogen in my muscles while in ketosis, does this eventually get restored by gluconeogenesis from diet or existing muscle, and how long will it take? I’m interested in what is happening in these early stages of keto adaptation as well as after I’m fully keto-adapted.

    1. It will take some time to get fat adapted. Keep exercise light for a few weeks. When I went keto, the only times I really had carb cravings was after long bike rides in the summer in the first couple months.

    1. Jen, we’ll be following up with a post on tea and intermittent fasting in the coming weeks. Thanks for your note. – M

      1. what about coconut sugar its supposed to be low GI index, ive replaced raw sugar in my coffee with Coconut sugar… Adele

  3. Recently I’ve learned how beneficial Kefir is,but it most likely stops a fast.

    1. Kefir is amazing, I can tell you that from personal experience. It had many unexpected positive effects for me. I expect it would interfere with fasting, but I would strongly suggest adding it to your eating window!

  4. Thanks Mark, I’ve been looking forward to more insight into coffee and fasting.

  5. Hi Mark, I realize this is a minor detail but could you help with the difference between half n half vs. cream in your morning coffee? When I look at the carb count for half n half, it seems insignificant enough. Is there really a big difference between cream and half n half to warrant one acceptable and one not? thanks so much!

  6. Hi Mark, I know this is a small detail, but I’m having a hard time understanding why half n half would be a no but cream a yes. Are they really so different? When I look on the carb count for half n half it is still only a gram. thanks!

    1. Caroline, check out my previous comment. If not having half-n-half in your coffee is a deal-breaker, then drink it.

  7. Hi Mark, I think you make a strong case for using coffee to enhance a fast. It makes me wonder what Dr. Satchin Panda, the brilliant Time Restricted Eating researcher, would say about all this – as he’s on the record recommending water only.
    Another great article though, looking forward to meeting you at Paleo FX this year.

    1. I’m glad you mentioned Dr. Panda. I was wondering the same thing. From what I understand, anything beyond water triggers the enzymes that would prevent a autophagy. Is that incorrect?

      1. Actually, Dr Panda has a fasting mimicking diet, where calories are consumed but your body thinks it is still fasting.

        And like Mark said, less atophagy is still some autophagy.

  8. What about decaf coffee? Does it still have the benefits listed above?

    1. I would really like to know the answer to this, as well! I find that I feel muuuuch better when I abstain from caffeine, but love my coffee so still drink decaf.

    2. I understand that decaf still has caffeine, it just to a lower extent. Did you ever consider 1 coffee per day of regular coffee and decaf there after?

    3. It says above that is study done with my using both caffeinated and decaffeinated ends that they still had autophage. So I’m guessing that you still would get many of the same benefits mentioned above by having decaf coffee.

  9. Great post! I will sure stick to black espressos when I don’t intent to breakfast (most of the days actually).

    “Nutmeg is fine, too. Just avoid psychotropic doses.” Thanks Mark laughed out loud here. I recall my buddies doing that when I was a teen but never resolved to try that psychedelic. Good thing too, “tumbling down the stairs without getting hurt or feeling anything” as my friend reported still goes against Primal Law #9 in my book!

  10. I’ve been fasting every Monday for the past 3 years. That’s 36-hrs from Sunday night till Tuesday morning. Not having coffee would be a deal-breaker for me. I have 3 cups of coffee on Monday, each with 1 T of half-n-half. If you think that’s not good enough, then stuff it. I always feel wonderful after my fast, and my body is trained to not need constant food-stuffing-in-my-face to regulate my blood sugar. When others are feeling weak and dizzy from lack of food, I can keep going and going like the Energizer Bunny.

    1. Personally I don’t think people should regularly schedule their fasts, should be more random, keep the body guessing… more “Primal” this way. Just my 2c.

    1. I have the same question too! Am using Crio. Rru (toasted cocoa beans, brewed like coffee – delicious!) as a cofffee substitute. Not sure how it fits into a fast however. I just drink it as is, nothing added. Any thoughts appreciated!

  11. Hi Mark, what about taking some BCAA’s during the fast to spare muscles? I’m trying to gain muscle and do my fasted workouts with some BCAA’s in my water bottle. Does this limit the fast? Thanks!

  12. In the tea post, would you please clarify effects of mixing even tiny amounts of protein with green tea? I read that it reduces the beneficial effects of fat burning.

    1. Plain green tea and black coffee are basically flavored water. When you start adding other components it becomes a horse of another color. Some people throw everything but the kitchen sink in their coffee. Doing so likely does break the fast, but there are degrees of fast-breaking. For instance, coffee (or tea) with a small amount of half & half in it–which does contain protein–isn’t nearly as much of a fast-breaker as, say, a chocolate chip cookie. Seems to me it’s all about how much work your digestive system has to do as to whether you can call it fasting (versus just kidding yourself). Hopefully Mark will cover all this.

      1. Actually, the digestive enzymes in your body (including, to some extent, insulin) are activated first by the flavor of food. So, even black coffee, tea and just flavored water could activate your digestive system enough to interfere with a fast. I’ve found it easier to prevent hunger while fasting by not introducing any flavor, I stick only to filtered water. Better safe than sorry, if I’m going to fast I want to make sure I’m not taking in anything at all that may hinder the results. All the articles fudging with whether this or that will break a fast are all speculative. A true fast is water only, so that’s the best way to do it.

        1. I identify with this one; I find that coffee in general increases my appetite (I am currently trying to ween myself off of it, to at least take a break; took a 15 day break once, and felt great)…but I love the stuff! Yes; using Swiss Water decaf to help come off the coffee. Am currently researching how coffee may be increasing my cortisol. For me, a true fast would be without the caffeine. 🙁

  13. I put 2 tablespoons of soy lecitine in my black coffee – it contains plenty of choline which is superb for your brain – and it’s almost fat, so it should not break the fast, or does it?

  14. This is really helpful, thanks! I was wondering about this as a typical day for me is bulletproof coffee with some collagen, mid-morning coffee with a splash of cream and then not eating till lunchtime. If I really feel the need for breakfast, I’ll have it, though. I might play around with having collagen later in the day, if I’m not so busy on those days, or sometimes just going for black coffee instead.

  15. What about prescription medications and autophagy? I take daily thyroid meds in the morning on an empty stomach. Since I fast til lunch, I can push this forward until 9 or 10 am, keeping it within an overall 10 hour window (eating in just 6 hours). Sometimes I think it would be good to fast 36-72 hours to really amp up autophagy, but is that a waste of time if I still take the meds?

  16. Hi Mark, can you address another proposed benefit of fasting and the impact coffee could have on it? I’m speaking of… let’s call it ‘digestive rest’. In at least one interview, another researcher suggested that ingesting anything other than water during a fast would trigger the production of digestive enzymes with a lifespan of about 10-12 hours. So keeping all eating (including black coffee) inside that window would be the only way to avoid producing more of these enzymes and allow the digestive system to rest during the fast. Would appreciate your thoughts.

  17. Can someone explain how non-dairy powdered creamers play into this?

    I assume because it’s processed it must be bad, but what impact does it have in our diets and especially with fasting?

  18. This was super helpful…thank you! I do put collagen and fat (coconut oil or grass fed butter) in my coffee, along with other “add -ins” depending on my mood. Many times raw cacao, maca and cinnamon. I just find doing the collagen in the am insures that I actually take it, and it is the one thing that I can’t live without (mostly for my skin…firmer now at 51 than ten years ago) Some days the blended coffee holds me till lunch or beyond, other days (like today) I’m truly hungry in the am. So for now I’m just going with the flow and listening to my body.

  19. Mark, I’ve hard Dr. Rhonda Patrick and Dr. Satchin Panda say that consuming anything the body has to metabolize starts some biological clock having to do with your circadian rhythm. So I’ve been operating under the assumption anything but water breaks fast. What say you?

    1. I also listened to that podcast. My take is that I’m not taking a break from my circadian rhythm, so drink that coffee and let it get started.

  20. It’s good to know that it does not break my intermittent fast. I try to fast one day a week for 18 hrs or so and usually drink three cups of black coffee during that time. I fast from 8:00 one evening till late afternoon the next day. Typically I end it with small protein snack around but try to keep it under 100 calories. I am interested in the upcoming blog post about fasting and tea.

  21. Thanks for this website. It clarifies so much hard to understand nutritional complications. Keep it up and health to all.

  22. Hi Mark,

    I always wondered..

    therefore normal, organic, full cream milk in coffee would be FOOD that instantly breaks the fast..

    Thank you for clarifying


  23. That’s OK, I’ll continue to truly fast by sticking to drinking only filtered water and not taking any supplements or adding anything to my water. That way I’m not taking any chances that the fast is being broken or minimized by adding chemicals or nutrients that change the benefits I’m fasting for. I’ve done 12 day water-only fasts with no problem at all, so there is no need to add anything and hope it’s not breaking the fast.

  24. Thanks mark this is so timely I am currently doing IF and trying my first 24 hour fast today so will have a few cups of black coffee to get me through. Is black tea the same? Doing a gut reset and on the Pau D’Arco tea at the moment.

  25. At some places, I’ve read coffee on an empty stomach every day is not good. How true is that? Thank you!

      1. It depends on what kind of coffee you’re drinking and how often you clean your grinder. The oils in the coffee can oxidize. if you don’ clean it regularly it probably won’t be good for your stomach, especially if you have stomach issues.
        I suggest organic whole bean coffee and grind them yourself. Make sure to clean it regularly and wipe it clean so the oil and dust isn’t there to oxidize.
        I have some health issues so it’s noticeable for me.

    1. I’ve done extended fasts with only coffee and water. No issues.

  26. So glad you posted this. I usually fast 14-16 hours every day. I generally break the fast with a cup of coffee, not because I am hungry but because I enjoy a good cup of coffee. I buy organic green coffee beans, I roast them then cold brew them. Mornings are usually 2 cups of black then in the afternoon a couple of cups with almond milk and maybe a few drops of stevia. Thanks for the article

  27. Thank you for publishing this article and slowing down the hamster wheel in my brain for at least the morning!

  28. I’ve seen both sides to this discussion before. I agree with your idea that it depends on what you’re looking for. People fast for many different reasons and define fasting in many different ways. There is no single answer to the question and that’s entirely okay.

    1. honey contains extremely high amounts of sugar so honey does break the fast

  29. So coffee increases cortisol. Is increasing cortisol a beneficial or detrimental thing to do during a fast? I speculate that it would add to stresses in the body but I suppose it matters how well a person manages cortisol.

  30. Well this comment doesn’t have all that much to do with coffee. More about nutmeg. Don’t get me started, eh? I will say I don’t recommend huge doses.
    Just reminded me that I found a previously opened but almost full bottle of Pure Leaf tea today. After holding it up to the light to examine and making sure there was nothing floating in it and then smelling it, I decided to keep it. Yeah, I’ll finish a stranger’s drink or food (got cold take-out ribs from a dumpster for breakfast yesterday!) – hope it does’t have rohypnol or something like that in it. It’s certainly got a ridiculous amount of sugar though so I plan on trying to ferment it. At first I was eager for the bit of caffeine, which I woke up feeling was quite a necessary hack today as I’m a bit run down and felt like a zombie, then I decided to just wait and make a minor walk to a drop-in center and load up on free coffee there, which was the plan for the afternoon anyway. It’s off-putting to see 47g of sugar on the label of a 473mL or something bottle (scary!) and I’ve never tried kombucha and would like to know what all the hype is about.
    Occasionally I brew my own simple wines (basically any kind of juice with sugar and yeast – let it sit for probably at least a week in a bottle with a cap on loose so the C02 can “burp”), which I should maybe do more of because it’s a money saver. I’ve never pasteurized any of the “brews” that I made but maybe that would be a good idea because I recently read that eating live yeast can be bad as they will devour all the b vitamins in your digestive system. I like a fresh, fizzy brew though – before drinking them, when they don’t taste all sugary, I like to leave the caps on airtight for a while to let them get carbonated.
    I consumed a bunch of nutmeg a couple times in an attempt to get high back when I was 16 or so. The first time a friend and I choked back a bunch of powder with Coke over our high school lunch, which didn’t seem to do anything. Although I like nutmeg its taste can be very overpowering in large amounts and for a long time after that I could “taste” it every time I drank Coke, which at least made me stop drinking Coke for a while.
    The second time was with the same friend and we boiled whole nuts with some crude grade dark chocolate and leaves from at least one type of wild plant that we thought might be hemp or a relative because it looks fairly similar. We were like why not, let’s just throw in anything that we think could make it more of a mind altering potion. It basically turned into a gross tasting muddy brew. Although I didn’t really feel “high” I was kind of out of it, even somewhat through the next day (which was kind of interesting because it was my first tackle football game (a scrimmage before the actual season games started, but same thing – I did alright at least)). At one point my mom called home and asked me to take a Delissio/whatever pizza out of the freezer and then cook it so dinner would be ready when my parents got home. I remember going to the freezer and taking out the pizza, but then when my mom got home she wondered why I had just left it on the floor outside the freezer, which I did not remember doing. That’s basically my experience with nutmeg, so in both cases it was pretty much pointless.
    I have heard of people getting really messed up on it like some guys who stole it from a rehab kitchen and ended up lying on the floor disoriented and hallucinating in delusional pychosis. I don’t have plans to try it again. That sort of drug (I call them zombie drugs) isn’t really appealing to me, like diphenhydramine, dimenhydrate, or datura, which all made me groggy and helpless with hallucinations I couldn’t distinguish from reality. It was interesting sometimes but overall not fun being clumsy, slow, sedated, and basically insane.

  31. I recently read that the ingestion of the caffeine is what breaks the fast as the liver is activated to metabolize the stimulant.

    The again, I read the first paragraph and realized that I do get hung up on minutiae !

  32. So, if one were to eat dinner at 6pm, and not eat again until the next day around noon (18 hours between meals)… that’s technically intermittent fasting? That *could* explain why I don’t weigh 600 lbs. Don’t get me wrong – I weigh too much, but not morbidly so. (Not yet at least, lol.)

  33. Hi everyone! I’m currently having to take antibiotics to clear up an eye infection and I really want to do at least a 24-36 hour fast to stimulate autophagy and just to feel better. Love this post about coffee not interfering (what a relief!) I’m wondering if the antibiotics (the kind I’m on don’t necessarily have to be taken with food) or my other regular vitamins will inhibit autophagy? Thanks in advance!

  34. I heard about breaking fast with coffee but I thought before reading this article that it’s not good for health but now I see it is totally wrong! I am gonna also try in this coming Ramadan’s fast-breaking with a sip of coffee. Thanks to this website 🙂

  35. What about using MCT powder in coffee? I am doing a program of intermittent fasting to increase autophagy, I don’t want to loose that benefit, but it’s hard for me to drink black coffee

  36. Hello
    I’d like some helpful honest advice regarding a coffee substitute made from malt and chicory.
    I have started fasting away from work and during a period of little exercise due to injury but when I go back to work; 12 hrs a day, 7 day week for 4 weeks I will be exercising again.

    I gave up caffeine in January and cut swiss water decaf in march. This has hugely improved concentration, irritability and irrational emotions, and my sleep. Getting rid of the coffee lost the bloats and constant gurgling.

    So I found a coffee substitute because nothing else I tried could I force myself to drink to stay hydrated when at a desk for so long; water, mint, ginger, lemon…

    Even if I am only using 1/4 teaspoon per mug when it recommends 1-2, am I doing my fast a huge disservice or is it more important that I am hydrated?

    Genetically my family processes caffeine terribly and I will not go backward but need some advice going forward.
    Thank you.

  37. Not related to coffee, but what are you thoughts on BCAAs during a fast? Specifically, for those that participate in intense training (cross fit, HIIT, bodybuilding, etc) during the fasted period, do you think adding BCAAs is beneficial or does it break the fast? Does it have a similar impact to the fast as you describe collagen in this post?

  38. I adore my coffee. I love IF as well. Just curious why I almost never see anyone mention that coffee does indeed have calories in it as well?

  39. What about the thought that coffee (or anything other than water) must be metabolized by the liver and gut, therefore causing certain enzymes to be released? It may not have an effect on insulin levels in the blood but there is still a metabolic response, especially with the caffeine. Could you get more into circadian rhythms and time restricted eating? (I know it’s not quite living awesome if you are hesitant to enjoy that cup of coffee in the morning, but damn if the minutia isn’t interesting:)

  40. Very helpful article. You mentioned about cinnamon and nutmeg being acceptable to add to coffee during an intermittent fast. Does this hold true for other spices as well? More specifically turmeric, cloves, ginger, or cayenne? Although I like the standard butter/MCT oil only version – adding spices, especially an anti-inflammatory blend has been interesting to me. Let me know what you think!

    1. Id like to know this also! I add macca, fenugreek & cordyceps mushroom poweder. Sometimes tumeric/black pepper & moringa

  41. Does zero calorie and suger free energy drinks break IM fasting? I like to have one in the AM instead of a cup of coffee.

    Thank you

  42. I’ve been doing 41 or 42 hour fasts with one cup of coffee 2 tablespoon half n half, near where I would normally have supper, lost 20 pounds in a couple of weeks no problem. Now didn’t lose anything past week, so I did a dry fast for a test, but only once, didn’t do a thing for me, didn’t loose anything, major bummer.

    I just started reading about autophagy, and its seems the 2 grams of protein in the half n half would stop it, so I’m just going to doing water during these hours now, because I want the fat loss and the autophagy, but I prefer 41-42 hour fasts to a fast that lasts for several days, I think it’s easier to do. Still a long way to go, but for some reason my resting heart rate is in the low 50’s and today it actually reached 48, (so I’ve must have had some improvement), according to the the heart rate charts and my age I have the resting heart rate of an athlete… just waiting for my body to catch up now.

    Last time I did the fasting, it was one day on one day off, I stopped when I stopped losing weight. I would just have water, but a coffee first thing the next day, that lost me 20 pounds in 30 days. That was before I heard about the 5:2 or IF, it was just a couple months to see if I could save money, and live on less since I wasn’t always getting a ride to the grocery store every week. Once had to wait 7 weeks, then only had 20 minutes to shop when I did, I now stock up when things are 50% off or cheap.

    I don’t drink a ton of water during the fast now because when I have my first cup of coffee on the eat day, at noon, but won’t actually eat anything till like 2pm, my digestion goes into overdrive, and a ton of water and no food, side effects, not good, LOL. Meanwhile, I’m saving more than 50% on groceries for the month, plus some toilet paper. Just trying to eat through whatever is in the fridge and freezer plus the extra rice and pasta I store. I’m on Disability so I only have $15 dollars a day to live on after my shelter costs went up, and they took the extra money from my food budget.

  43. I do daily intermittent fasting and am currently drinking Wicked Joe Organic ‘Bella Maria’ coffee. I am drinking this black without any additives. I have heard that drinking ‘flavored’ coffee will take you out of a fast. Any idea on this??

  44. My issue with your article is you make a claim that caffeine helps which may be but coffee is more than caffeine it was organic material. Does that cause insulin to be released is the question. I hope you get that.

  45. Thanks for dealing with this very common question. Its great to clear the confusion does the coffee break an intermittent fasting. This shared article also included common health benefits of fasting and common additions to coffee.

  46. Thanks for this article. I have looked around desperately for info but can’t find anything reliable and I’m hoping you can help. I am not a coffee drinker. I know, “oh the horrors”. I do prefer black tea. Not green tea either, it is awful. Don’t even talk to me about the vile stuff. I have had some fanatics berate me that having any flavorings in my black tea “breaks my fast”. And I’m not talking creamers etc. I mean cinnamon and orange peel or raspberry or blueberry etc. basically still zero calories but I’ve been told the flavors trick the body and mind and it won’t go into aphagy, or causes insulin resistance etc. Help me out here please?

  47. So when ordering a coffee is a cappuccino with skim milk a no go? And also is there anything else easy to order instead of black coffee that wont break my fast? Thanks in advance

  48. What about adding raw honey to black coffee? About one or two tblsp? Did that break the fast? Benefits? Drawbacks?
    Thanks so much. Great article.

  49. My husband and I have been doing the Keto diet for about 6 weeks now. We have tried ALL the recommenced sweeteners in our Keto coffee and can stand any of them! This has been our biggest challenge. I finally resorted to a teaspoon of coconut sugar in 16 oz mug of coffee – also 1 tablespoon of MCT oil, 1 tablespoon of coconut manna & a splash of heavy cream. Will this seriously jeopardize our Ketosis??

    1. Have you tried allulose? I can’t STAND artificial sweeteners of any kind, but this is derived from actual sugar but is undigested by the human body so just passes through your system. And it tastes JUST like sugar, only a little less sweet.

  50. What about BCAAs and black coffee? I workout at 5:30am and I am trying the fasting period of 8pm – 12pm in hopes of loosing weight (my belly) but not muscle. I heard zero calorie BCAAs will assist in maintain muscle. Is this true? and will it break my fast if I drink the BCAA after my workout and later in the morning drink the black coffee?

  51. I’m wondering about full fat coconut milk or coconut cream…

  52. Hello, thanks for you article is very helpful for us

    I can’t drink black drinks, what other drinks can I drink while I’m fasting?

  53. I use Raw, unfiltered Honey with my coffee. What’s the impact of Honey?

  54. What if you’re drinking somewhere around 60oz of black coffee in a 6 hour period. I fast every day from 6pm – 12 or 1 pm. I ususally drink black coffee all day. Will the amount of black coffee incur negative results?

  55. Hi Mark,

    Does warm water with lime or lemon breaks/affects the fasting? What about warm water with apple cider vinegar?

    Thank you.
    Luana Borges

  56. What about taking biotin/collagen pill-based supplements and/or fish oil (pill) supplements? How about fiber capsules? Are there supplements to avoid in order to avoid breaking the fast or dropping out of ketosis or autophagy? (I’m talking single daily doses of these supplements usually in single-pill form. Except for psyllium fiber, where the daily dose is 5-6 capsules of psyllium husk / Metamucil.)

    1. Eric, thanks for your question. I’ll be doing a post soon on supplements and fasting and will be sure to cover fiber supplements as well as others you mention. Best — M

  57. Absolute bullshit. The reason caffeine ever gives positive benefits to ANYONE is because that person is already IN caffeine withdrawl, therefore injesting caffeine reverses the damage temporarily that it already caused. How dont people see this? Because youre addicted? Yes.

  58. Thanks! Came here to find an answer to exactly that question… while sipping on my coffee! Moreover, you even answered my next question as well (whether cinnamon is a problem).

  59. I love how you broke this all down. It really answered all of my questions. Thanks!

  60. Great article on coffee and IF thanks. I was wondering what are your thoughts on having coffee with a splash of skimmed milk (we call it across the pond). Or, alternatively fat free milk? Thanks.

  61. Mark, some of the coffee beans we buy are flavored (i.e. Hazelnut, Chocolate, Amaretto…). Will these break my fast?

  62. Effect of adding <30 grams pure fiber to coffee during autophagy fast.?

  63. I like my coffee like you do. Though I’m parcel to cold brew.
    I had a thought while reading your article here. What if we grind the beans in cold water, would that eliminate all the oxadation? Do we fermint coffee?
    Thanks for your articles. ?

  64. So a little bit of milk from nut pods and some liquid stevia is OK?

  65. Hey Mark,
    I’ve been following you for some time and just want to thank you for the resources and products you provide.

    Quick question new to IF. I drink black flavored coffee. I’m not talking syrups but actual flavored coffee beans from a local coffee shop. Will this break my fast?

  66. Hey Mark (and community),

    How about Mushroom coffee & teas? I blend Foursigmatic into decaf black coffee every morning and then add even more Lion’s Mane and Chaga to my brew. It’s delicious and makes me feel energized without the jitters.

    I’d love to know the mushrooms’ effects on fasting & autophagy.


    ps – I was actually a guest on podcast episode 229. I’ve been a decade-long fan of you and your community – you inspired me to get into the biz! Thanks for all you do and who you are.

  67. Thanks for the efforts you put in digging out the stuff. It’s not easy. One thing stands out here that is hindering my acceptances in the things said. You fail to back up with references, all you said with scientific discoveries. A lot of different opinions on health issues, there by making very hard to believe some. I don’t have the scientific knowledge or sense to argue.
    But be it as it may be we need a little conviction because life is involved.

  68. Oh this is really new to me, i never knew that coffee breaks the fast and these many factors are associated with the coffee. Thanks for sharing this insightful post with us. Keep sharing in future as well.

  69. Just a quick question, please. Since I can’t drink coffee (I become like a gerbil on meth when I drink it–it’s not pretty), I have been making herbal teas with grass fed butter, MCT oil, or heavy cream instead. Am I safe in assuming that the same rules for fatty coffee apply here? Thank you so much for all the information you put out.

  70. That’s an excellent article about coffee and how it related to fasting. And moreover, incredible thing is, it gets the coffee with a combo and its effects.

  71. Hello Mark,
    A great post on what good coffee can do to the body and how we should drink it.
    Also, I have read that drinking cup of coffee half an hour before working out increases fat burn. Is this true?

  72. I really loved this article! Detailed in a way that answers all my questions!
    And Also, I appreciate This App! My number 1 Ever! Great job .. :)))))

  73. I really loved this article! Detailed in a way that answers all my questions!
    And Also, I appreciate Zero App! Where I found this great article..
    Best app Ever For Fasting! Great job .. :)))))

  74. Please include coffee with plain milk (full, semi, skimmed options).
    One of the most common things added and yet it’s not on the list above.

  75. Does unsweetened coconut milk, light or regular in a coffee affect fasting?

  76. I have been doing 16/8 Intermittent fasting for about 3 weeks and try really really hard not to have my coffee before the 16 hour window.
    I love to have a bit of coffee with my creamer and full spectrum hemp or maple syrup or stevia. I see you recommend heavy cream instead of half and half. Sounds Devine. How would all the above effect IF if taken before the 16 hour window? Thanks

  77. According to your article, it appears that coffee actually improves the effects of fasting and ketosis. I don’t drink coffee, but is it worth it for me to start?

  78. Hello
    Do 2 tablespoons of acacia fiber in black coffe break the fast please?
    Thank you very much!

  79. this is depends on which type of coffee you are having if you are having cream coffee that definitely it will break your fast but if you are having plain black coffee it will not…

  80. I’m still seeing no information about drinking coffee with milk in it (during fasting hours). I can’t face the day without my cappucino which includes several ounces of 1% milk. Could you please comment as to the relative damage inflicted by differing fat levels–from skim to whole milk?

  81. Hi, I usually add a few other powders to my morning coffee, could you please comment on this brew?

    Black coffee
    MCT oil
    1 teaspoon macca powder
    1/2 teaspoon fenugreek powder
    1/2 teaspoon cordycepts mushroom powder.

    I also add cinnamon (which you have addressed). Thank you

  82. I have never tried black coffee. Instead, I always prefer to have creamy, frothy milk coffee, and also love to include chocolate syrup. But, since I have decided to lose weight, my friend suggested me to leave the milk coffee. More to that, she said if I can opt for black coffee, then it would be best. I didn’t lend my ear to her suggestion until I read your detailed article. Thanks!

  83. This was great to read. The writing style was very personable and easy to follow. I really felt like I was sitting down across from an old friend, drinking a nice cup of coffee. Besides style, the information was easy to follow without being too overwhelming and I learned a lot in a matter of seconds! I appreciate this article. Thank you ??

  84. Wonderful post. I think if it is not related to getting fit, in India if we have coffee during the fasting period we are breaking our fast.

  85. Hi,I’ve been a low carber for the last 15 years after discovering I was insulin resistant/pre diabetic.I read everything I can get my hands on regarding any form of low carb dieting to educate myself and keep ahead of the game.I’ve just been re-reading my Wheat Belly book,and in it,Dr Davis says post- meal sugars should not exceed 100 on the glucose meter,and that amounts greater than that are triggering damage.My previous understanding was that damage begins in the upper 130’s.(even with low carb- less than 30 or so grams a day,my fasting sugars are often over 100.I know this happens to other low carber s too..)What say you?