Things that Break Your Fast FAQs

Will _________ break my fast?”

That’s one of the most commonly asked questions in intermittent fasting forums and social media groups. In fact, various forms of the question are asked so often that long-term forum members often roll their eyes and react less than welcoming when it pops up from a newbie.

I will never react that way to any question regarding things that break your fast because I understand that intermittent fasting is a difficult lifestyle to adopt. It takes a lot of trial and error to learn the ropes and figure out what works best for you.

I drank zero-calorie flavored waters for months before realizing that the flavor was spiking my insulin and breaking my fast.

I now know that’s called “dirty fasting,” but I didn’t want to do it dirty. I wanted results as fast as possible, and ditching the flavor was necessary for me. You may make a different choice for yourself, and there’s nothing wrong with that.


What Can You Have While Fasting?


The fasting period should give your body a break from processing food. That time is spent repairing and healing internal damage, boosting your immune system, and strengthening your system in general. Many health benefits of intermittent fasting are a result of consistent fasting over time.

Imagine repairing and replacing damaged or diseased cells and turning the clock back on your aging process.
It will happen, but only if you’re honest about what you’re consuming during the fasting hours.

In general, you should consume no solid food while fasting. That includes diet foods and low-calorie foods.

If it hits your stomach and requires your system to process it like food, you’re breaking your fast.

If it contains even 1 gram of carbohydrates, protein, or fat, you’re breaking your fast.

If it contains zero calories and zero nutrients but is solid and has flavor, you’re breaking your fast.

To get results from intermittent fasting, just stick to liquids during your fast. So, what liquids can you safely have? Water without flavor is your safest bet, though many people can safely add lemon without spiking their insulin.

How do you know if something spikes your insulin and ends your fast?

You will likely notice that you get hungry after consuming it.

You may also notice that you start having food cravings, but that may come as you progress into a more seasoned faster. It can take some time for your body to adjust and stop triggering those cravings, so you may not know whether you’re having cravings as the result of something you drank or just because your body is adjusting.

Eventually, you will know because you will stop feeling hungry and experiencing cravings while fasting, YES, that really does happen! I never believed it was possible for me as a binge eater, but it happened gradually over time without me doing anything other than sticking to a clean water fast.

A clean fast includes plain water without added flavor enhancers or sweetener, but there are some other liquids that are safe for your fast.

You will not break your fast by consuming the following beverages:

  • Unflavored seltzer water
  • Black coffee (no added flavors, sweetener, creamer, milk, etc.)
  • Plain tea (preferably brewed from dry tea leaves) (no added ingredients

There are so many questions regarding which teas will break a fast that I created a special guide to teas and intermittent fasting. Take a look if you want to use tea to get through your fasting periods or just want a splash of tea here and there to break up your fasting diet of water, water, and more water.


Things that Break Your Fast FAQs


To help you understand what may or may not break your fast, I decided to create a list of Things that Break Your Fast FAQs.

Does smoking break your fast?

No, smoking will not break your fast. It shouldn’t cause an insulin spike or impact your blood sugar. You’re inhaling smoke, but it doesn’t enter your digestive system or require processing like food.

Will artificial sweeteners break a fast?

There’s a lot of controversy over artificial sweeteners and intermittent fasting. Research has shown that some artificial sweeteners may trigger an insulin reaction while others are less likely. I have talked to people who include some artificial sweeteners in their fast without any signs of insulin release while others swear they release insulin and break their fast with the slightest bit of any artificial sweetener.

I believe that artificial sweeteners take you out of the “clean” fast category and put you in the “dirty” fast category. This is one area where you can experiment to see what causes hunger, food cravings, or slower weight loss, and what seems to have no impact on your fasting.

Like I said above, I consumed sparkling water with zero-calorie flavoring and artificial sweetener when I first started intermittent fasting. I’m not sure if it caused an insulin spike or slowed my weight loss because I was just starting out and had nothing to compare it to at that point.

Today, if I’m really struggling during a fast I occasionally add a bit of flavor with artificial sweetener (zero calories) to my water. I’d rather fast dirty than not fast at all, but every person must make that decision for themselves. We’ll discuss dirty fasting versus clean fasting elsewhere on this site.

Will gum break a fast?

Gum does stimulate a small insulin release. It’s so minor that it’s not likely to interfere with fasting results, but many people argue that gum or any type of mints will slide you into that “dirty” fast category. This is another personal decision that we must all make.

I personally have decided that gum isn’t something I need but will use occasionally use if I need to freshen my breath quickly and have no other options. Swishing a small amount of peppermint essential oil around your mouth or using WOW Drops is an alternative that won’t break your fast.

Does diet soda break your fast?

Diet soda that contains no calories and shows “0” all the way down the nutrition label contains no nutrients. So, it shouldn’t break your fast, right? It’s basically water with a lot of added non-food chemicals, right?

Kind of.

The problem with diet soda is they all contain some type of artificial sweetener. Look at the FAQ above titled “Will artificial sweeteners break a fast?” for more details.

In general: It can spike an insulin response, which rules it out of fasting for anyone who believes in clean fasting. If you want to include it and call yourself a “dirty” faster, that’s a personal decision. You may also want to play a game of trial and error to see if you think diet soda triggers your hunger or food cravings.

Does bone broth break a fast?

I know a lot of people who consume homemade bone broth during their fasting windows, and they’re still very successful reaching their fasting goals. I have heard others argue that bone broth is treated like food in the body and does break the fast.

We’re back to the “clean” fast versus “dirty” fast dilemma. Like everything else on the list, it’s up to you to decide whether you want to allow bone broth while fasting or not. If you do try it and notice that you feel hungry or have food cravings after consuming it, that tells you that it is breaking your fast and may stand in the way of your results.

Do supplements break a fast?

Some supplements will break a fast while others will not. There are a few questions you should answer for yourself to determine if you’ll allow supplements while fasted or not:

  • Can you take your supplements on an empty stomach? If you need to take them with food, that answers your question.
  • In what form does this supplement come? Drops or topical products are less likely to impact your fast than pills, shakes, and food supplements.
  • How do you feel after taking the supplement? Does it make you hungry or do you get food cravings?

If you’re serious about maintaining a clean fast with no interference when it comes to results, you should probably leave the supplements for your eating window.

Do exogenous ketones break a fast?

Ketone supplements help put your body into a state of ketosis, which is naturally achieved with some fasting schedules as well. You don’t have to follow a keto diet or eliminate all carbohydrates to use exogenous ketones, and the good news is they don’t break your fast. They may give you energy and help you maintain ketosis if that’s your goal.

You will hear some people say that any supplement breaks a fast, but ketones are one of those supplements that aren’t likely to hold you back in terms of results. They do have some benefits if you want to maintain ketosis and burn more fat.

Does butter break a fast?

Butter often comes up for those doing intermittent fasting and keto. Adding fat to coffee or consuming bulletproof coffee which contains a source of fat is popular, but the butter is a no-no during your fasting hours. It will hit your digestive system like a food and require processing, which does break your fast.

Butter in coffee is another reason some fasters are happy to settle for the “dirty” fast category. The insulin response to butter is small, but it’s up to you to determine how important it is to maintain a clean fast.

If you want to add fat to your coffee, consider adding MCT oil derived only from coconut oil instead of butter. It is believed to support fasting and is sometimes used to help people following the keto diet enter ketosis. It technically may break a fast if you ask supporters of the clean fast, but it’s far less likely to trigger a complete break of the fast than butter.

Does vomiting break your fast?

If you’re vomiting, breaking your fast is the least of your concerns. If you vomit due to illness, you need to worry more about caring for your body and getting well than fasting. In that case, fasting may help stop the vomiting but there is no guarantee. Do not worry that vomiting will break your fast. Just get better.

Does brushing your teeth break a fast?

It is possible for toothpaste to cause an insulin release due to the flavor and the small amounts that may enter your digestive system. The impact is so minor that you should continue brushing your teeth whether you’re fasted or not. Trust me, everyone wants you to brush your teeth!

Will oil pulling with coconut oil break your fast?

Coconut oil pulling will not break your fast. You’re not consuming the oil, so it should have no noticeable impact on your fasting state.

Will prescription medication break my fast?

You need to take your prescription medication as prescribed. Some medications may break a fast while others aren’t likely to have any impact. You can research each medication you take, but keep in mind that taking any medication with food will break your fast. You can try to adjust your fasting schedule to take that medication during your eating window.

If you need to take medication two or more times a day due to illness or injury, you may need to adjust to a longer eating window or just take a break from fasting until the medication is no longer needed. It’s important to take care of your health, and medication is occasionally needed. The good news is that intermittent fasting boosts the immune system, so you may find that you get sick less often once IF is a routine part of your life.

Do you have other questions about what may or may not break your fast? Send me a message so I can include it in my Things that Break Your Fast FAQs.

16 thoughts on “Things that Break Your Fast FAQs

  1. It is wonderful to read your article on breaking your fast.  I do intermittent fasting whenever I can.  Most of the time after waking up in the morning I don’t eat until 12 noon.  I usually drink hot water with a squeeze of lemon in it so I guess that will not break my fast.  That is my routine for quite some time now.  Reading your article helps me to know what could break your fast.  Looks like in my case, I don’t have to worry as I don’t try to have any other liquid other than warm water in the morning after waking up.  Sometimes I have turmeric tea with no sweetener or anything.  Thank you for sharing your article with me.  Wishing you the very best of health doing intermittent fasting.



    1. Thanks for reading, Evelyn! I think you’re pretty safe with a bit of lemon in your water and the occasional tea. 

  2. Fasted once for 20 days on nothing except water with lemon and a teaspoon of honey once a day. Most recently I did an A1C test for a job and tested very high, though later I found out I was not supposed to have biscuits and gravy for breakfast and then take the test at noon.
    So thinking I had Diabetes 2 I started after reading Dr. Chung’s research with a seven day clean fast. Then I went three days on and three days off. Fantastic on all cylinders, lost weight and have kept it off, great increase in energy level. All around I just feel good. CQ

  3. Thank God you made this guide! I’ve been planning to go back to Keto because it really made an impact in my health, I only did it for 3 months, but consistency is my problem. I’d love to do a combo dieting with IF and Keto together, so details about breaking fast are crucial. 

    Thanks for this, Theresa!

    1. Yes, intermittent fasting and keto go very well together. I know quite a few people who have been very successful with that. Yep, consistency is key. It’s hard for us all. 

  4. Very good subject.  Dr Fung a Toronto Physician treats type II diabetes with intermittent fasting.  I started with 7 days clean and then 3 on, 3 off.  He uses one regular and 500 calories per day on the second day and he does this because every single bariatric surgery patient is cured of their type 2 diabetes because they can no longer eat enough to maintain harmful fat around the pancreas.  I lost 35 pounds and have kept it off for a year because I am simply no longer hungry all the time.  

    This is a great subject with the massive amount of Type 2 Diabetes diagnosed.  The health field in general is great for affiliate marketing.  It is among the top 3 categories from my understanding.  Traffic should develop swiftly as you target keywords in this niche.

    Thank you for sharing this important matter with us.  Chris   

    1. Wow! Those results are excellent! I always love hearing those intermittent fasting success stories. 

  5. Wow, thank you, thank you. My friend has been hassling me to search for somewhere online that will help her start fasting as she has recently become a Bahai and needs to fast every so often.

    She loves food and coming here will really help her get honest about what is needed to do a proper fasting so thank you and I will fwd your link so she can get learning

    1. Thank you for doing that, Vicki! I’m getting new content up as fast as I can. I have so much to share on this topic 🙂 

  6. Interesting article!  I used to fast regularly when I lived on my homestead on Spruce Island, AK,but have not done it very often since leaving there.  It could be something I should try again.

    It’s no problem with me to have just water when I’m fasting.  However, I now take supplements that I must take, because they keep my body in a healthy balance.  I don’t take prescriptions, but a number of herbs for certain kinds of healing.  It would not be good to leave them out, so guess I’d have to do a “dirty fast” and leave them in there.  I think it would still do me some good.

    Thanks for the reminder that fasting can be quite helpful.

    1. I don’t necessarily think dirty fasting is bad as long as you know you’re doing it that way and you have a reason for it. Supplements that you really need to take would be a good exception. There’s even a possibility that those supplements would have such a minor impact that it doesn’t really matter. Depends on the supplements. 

  7. I fast once a week from morning 8 am until 3 pm. I drink water and black coffee only. These two liquids are good for my fasting. I started this routine a year ago and it works well for me.

    Thank you for sharing information on what breaks the fast. It is very helpful.

  8. Thank you for this very informative article on fasting, I myself have tried fasting before and have made the same mistake of drinking zero-calorie, sweetened sparkling water hahaha. This will serve as a great resource to people like me who want to learn more about fasting so that we can implement it in our everyday lives. 

    The overall layout and organization of your post was very neat and tidy which made reading it very pleasing.

    Great Job

  9. Hello there, thanks a lot for sharing this wonderful piece of information here with us. I must say i really did enjoyed going through your article as it contains useful information’s one can hold on to. I must say these are really fast faqs because people always asks about these all the time. I think i will be sharing this with my friends now, thanks for sharing this

Leave a Reply

Your email address will not be published. Required fields are marked *