Will it Break My Fast? | Part II

It’s still the question we see most frequently: “Does [insert item] break my fast?” So we decided a Part II to our first post was in order. Let’s dig in to find out if fish oil, herbs/spices, CBD oil, or BCAAs break your fast.

Fish Oil

Fish oil itself is a fat, which contains 9 kcal per gram. The average dose of a supplement is anywhere between 1-2 grams, so if you take fish oil, your body will need to metabolize those calories. However, fat doesn’t stimulate insulin release, and the 9-18 kcal that the fish oil provides has minimal to no impact on your body’s ability to break down its own fat stores.

That being said, fish oil is a polyunsaturated fatty acid, which has to be digested and absorbed. Meaning—you guessed it—the gut will be stimulated after taking fish oil.

Fish oil is high in omega-3 fatty acids, which are anti-inflammatory. The molecules have been shown to decrease inflammatory cytokines such as interleukin 1 (IL-1), Il-6, and tumor necrosis factor (TNF). In addition to its anti-inflammatory properties, omega-3 fatty acid consumption is positively associated with the reduction of risk for many other chronic diseases such as heart disease, stroke, rheumatoid arthritis, and cancer. Some studies have even shown that both EPA and DHA (fatty acids found in fish oil) may induce autophagy.

In Summary:

  • Fasting for metabolic health: fish oil likely doesn’t break a fast
  • Fasting for gut rest: fish oil does break a fast
  • Fasting for longevity: fish oil likely doesn’t break a fast

Herbs and Spices

Most herbs and spices have fewer than 5 calories per teaspoon and have almost no impact on blood sugar levels or your fat burning ability. However, watch out for ingredients that often accompany herbs and spices, like sugar or those found in fat emulsions. Herb/spice blends that have sugar raise blood sugar levels and elicit an insulin response. Other blends mixed with fat have a higher caloric content. To play it safe, stick to pure herbs and spices, either fresh or dried.

Herbs and spices come from plants, so the majority of calories they have are from carbohydrates with a small percentage of protein. Roughly half the carbohydrates are fiber, which is undigested, but a small portion of the carbs that remain will slightly stimulate the gut for digestion and absorption.

The minimal calories and protein found in herbs and spices alone probably aren’t enough to inhibit autophagy. There are even a few studies that show promise with specific herbs promoting or enhancing autophagy.

In Summary:

  • Fasting for metabolic health: herbs and spices don’t break a fast
  • Fasting for gut rest: herbs and spices do break a fast
  • Fasting for longevity: herbs and spices likely don’t break a fast


Since CBD oil is fat, and fat alone will not kick someone out of ketosis, CBD oil is likely fine to have while fasting if your goal is metabolic health or weight loss. As long as the CBD oil doesn’t have any added sugar or another source of carbs, it doesn’t stimulate insulin (stimulating insulin will derail ketosis and fat break down).

If you consume your CBD oil orally and swallow it, it’s digested, absorbed in the small intestine, and transported into the liver to be metabolized. (The oil also usually has calories and fat that need to be broken down, too.) Therefore, CBD oil stimulates your metabolism and gut.

One benefit of fasting is reduced inflammation, and as it turns out, one common reason people consume CBD oil is for its positive effect on inflammation. A few studies have also shown a positive impact with CBD and its role in autophagy. So if you’re fasting for longevity, CBD oil shouldn’t derail the benefits of your fast.

In Summary:

  • Fasting for metabolic health: CBD oil likely doesn’t break a fast
  • Fasting for gut rest: CBD oil does break a fast
  • Fasting for longevity: CBD oil likely doesn’t break a fast

Branched Chain Amino Acids (BCAAs)

If you exercise, you might consume BCAAs, which promote muscle protein synthesis. They have also been shown to have positive effects on body composition and glucose levels. However, if body composition and/or fat loss is your goal, make sure to choose sugar-free BCAA mixes without additional carbohydrates.

All amino acids are digested and absorbed in the small intestine. In addition to that, almost all BCAA mixes contain additional ingredients outside of the BCAAs, most of which will also need to be digested and absorbed.

If autophagy is your goal, then protein supplements and BCAAs break a fast. When you fast, growth pathways like IGF-1 and mTOR are suppressed, which is needed for autophagy to occur. If you consume protein during your fast, specifically BCAAs such as leucine, you will stimulate these pathways and inhibit autophagy.

In Summary:

  • Fasting for metabolic health: BCAAs likely don’t break a fast
  • Fasting for gut rest: BCAAs do break a fast
  • Fasting for longevity: BCAAs do break a fast

Surprised by one of these? Let us know what you thought in the comments, and request other items for us to cover in this series.

Posted in Does It Break My Fast?


  • I have read that under 50 calories will not break a fast eg kess than half cup soymilk in coffee in the morning. Is that correct

    • It’s like everything else. If you do it for weight loss or longevity then it will not break your fast. If you wanna give your gut a rest, it will break your fast.

  • Does supplements like vit c, vit e, collagen and pills break fasting? I know there was an article about it that we should drink it within our eating window. However there are supplements that we take in a timely manner. Like if i’ll do 23:1 fasting and in a specific tym i should take supplements beyond 1 hr eating window. Will it break my fast?

      • Stevia does not break a fast. There’s a whole article on this app that describes just that. It is ok. Ginger water depends on calories. If it has calories it’s going to affect gut rest or fasting for longevity. It may not affect metabolic health .. lemon squeeze is ok. Not a lot. Again. Depends on calories and your overall goal.

  • Great info and great app!
    What about coconut water?
    And spirulina? There are moments during fasting that my hunger feels like it might get the best of me. I take a handful of spirulina tablets and I’m good to go?
    Thank you, keep up the good work!
    Kind regards, Kim

  • Hi, can Raw coconut water (not processed or pasteurized) break a fast for weight loss and logevity purpose?

  • Just wondering about fasting on TRT. Does injecting testosterone affect suppression of IGF-1 and mTOR? i love the zero app but am worried I’m not getting the best fast on TRT. Thanks

  • This is great . I’m wondering about other ingredients. Specifically those found in most pre workouts . If that breaks a fast . A lot of people ask this !

  • “Does lemon water break my fast?”
    I mean if I take a fresh lemon, cut it on the middle, extract the “juice” in a cup and add cold water, without any other ingredients, does it break my fast?

  • Hello, thanks for the advice.

    I am also wondering about the lemon in warm water? I usually grate the skin in it too. Does this break the fast?

  • I’d really like to know the details of apple cider vinegar in terms of fast breaking.
    I’m pretty sure it won’t break a fast for metabolic health or longevity – but I’m not sure about gut health.
    Vinegar is acidic – will it stimulate digestion?

  • Hi,
    So I am doing intermitten both 16/8 and 18/6 and sometimes longer. Now I want to go into a 3 days 44 hour fast. But I usually have a cup of fresh ginger, lemon, fresh turmeric and matcha powder in hot water daily. And I was wondering if I can still have that on a 3 day fast when I don’t have any breaks? And if not all of the above, which can I keep? Also fish oil and magnesium supplements.? I am doing this for longevity reasons.

    Also Is lemongrass ok to put in your hot water on a total 3 day fast or not?

    Thank you so much! 😊

  • We need to make a searchable list of things that break this fast it that fast, etc. and our it in the app. Keep updating as more questions from more lifestyles roll in. 👍

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