Affiliate links on our site may earn us commissions. Learn More.

This website uses cookies. By continuing to use this website you are giving consent to cookies being used. Visit our Privacy Policy.


Discover The Best Wellness Tips In Your Inbox

Subscribe to Health Reporter’s newsletter and get our health experts’ highlights and the latest news about healthy living.
The newsletters are spam-free and sent from our health experts and professionals.

Thank You!

You have successfully subscribed to our newsletter!
Home arrow Nutrition arrow Intermittent Fasting arrow Does Bulletproof Coffee Break a Fast? A Nutritionist Explains The Science Behind It

Does Bulletproof Coffee Break a Fast? A Nutritionist Explains The Science Behind It

Written by Thalia Oosthuizen
Fact checked by Rosmy Barrios, MD
Last update: October 22, 2023
2 min read 1598 Views 0 Comments
clock 2 eye 1598 comments 0

Bulletproof coffee is a huge trend right now for the health benefits it provides. Should you avoid it when fasting?

does bulletproof coffee break a fast

Sometimes when you’re fasting, you really need that morning pick-me-up. For most people, morning coffee is their go-to for a boost of energy throughout the day. But what about when you’re fasting?

Our fasting experts take a look at bulletproof coffee and if this particular type of coffee has any effect on whether or not it will break a fast.

Does Bulletproof Coffee Break a Fast?

Whether or not bulletproof coffee entirely breaks a fast depends on how you’re fasting. For some people, their fasting window means that they have as few calories as possible. For others, it means having reduced calories.

For intermittent fasting, bulletproof coffee is probably one of the last drinks you want to have. Unlike plain black coffee, bulletproof coffee is high in calories. It was originally made to be a complete meal replacement, which means it needs to feed your body energy.

Bulletproof coffee has about 230 calories. This is much lower than the recommended 500 calories or less when it comes to intermittent fasting. Technically, coffee with fats does indeed break your fast but causes much less disruption than something high in carbohydrates.

What Is Bulletproof Coffee?

Bulletproof coffee is a high-calorie coffee drink that was intended as a replacement for a breakfast meal.

Originally, bulletproof coffee (also sometimes called butter coffee) started trending years ago among people who were into the paleo diet lifestyle. 

According to the recipe, bulletproof coffee is a cup of brewed coffee mixed with grass-fed butter and MCT oil.

Bulletproof coffee has also been popular among people who follow the keto diet because of its high-fat content. People who drink bulletproof coffee often are doing so because it replaces other meals and offers a boost of energy.

Pros and Cons of Bulletproof Coffee

Bulletproof coffee has some benefits, as well as some downsides. It all depends on what you’re looking for when it comes to a diet.


  • Great for the ketogenic diet because it’s high in fats.
  • Contains very few carbs, which helps your body stay in ketosis, burn fat, and lose weight.
  • Helps your body not feel as hungry and avoid overeating.


  • Contains up to 2 tablespoons of butter, and a large amount of saturated fat.
  • Replacing solid food with a drink might leave you feeling worse throughout the day.
  • You still need other nutrients for healthy weight loss. 

Does Bulletproof Coffee Stop Autophagy?

Autophagy is the body’s clean-up process. Your body goes through autophagy automatically, but intermittent fasting encourages the process quicker and for longer periods of time. Autophagy helps your body reduce, reuse, and recycle dead or dying cells.

Butter coffee does not block or stop autophagy. In fact, this particular type of coffee actually helps promote ketone production and ketosis, which, in turn, helps trigger autophagy outside of an intermittent fasting state.

Bulletproof Coffee Recipe

Time to prepare: 5 minutes


Brewed coffee 1 cup
MCT oil 1–2tbsp
Unsalted butter, grass-fed 1–2tbsp

When it comes to MCT oil, you may want to start with just 1tsp and build up to more when you get used to drinking it.


  1. Brew your coffee to your liking.
  2. Add MCT oil and butter with coffee into a blender.
  3. Blend for 30 seconds until foaming

A Word From Our Nutritionist

If you’re someone who loves to drink coffee, even if it’s just a nice cup of black coffee, then you might enjoy the energy boost from something like bulletproof coffee, especially if you’re worried about breaking your fast.

When you drink black coffee, it doesn’t break your fast because it has negligible calories and it doesn’t stimulate your digestive system.

When you consume bulletproof coffee, you consume more calories, but it causes fewer disruptions than eating solid food with carbs.

After all, there’s a reason that this coffee is called keto coffee!

If you’re practicing intermittent fasting for gut rest, this particular type of coffee also encourages gut health by not stimulating the digestive process.


Now you know everything there is to know about bulletproof/butter coffee. 

While this coffee has its benefits, there are still some fallbacks when it comes to drinking it too much or using it as a meal replacement. 

Does bulletproof coffee break a fast? Well, you can drink it on a fast, depending on how you conduct your fasting period.

However, it’s much more suitable to drink during your eating window just before you go into fasting, as it ups your energy and encourages you to stay in ketosis while you’re fasting.

Written by Thalia Oosthuizen
Thalia has always wanted to be a writer, starting her first local newspaper at the age of 11. She also has enjoyed a passion for health and fitness since a young age, playing many sports through her schooling career, and still enjoys biking, running, and swimming today. She studied English Language at University for 3 years, developing a passion for spelling, grammar, and research. She now has over 10 years of experience writing, proofreading, and editing, and has paired this with her love for health and fitness by writing health content.
The article was fact checked by Rosmy Barrios, MD
Was this article helpful?
Thank you! We received Your feedback
Written by Thalia Oosthuizen
Fact checked by Rosmy Barrios, MD
Last update: October 22, 2023
2 min read 1598 Views 0 Comments

Leave a comment

Thank you for your comment!
We will review it as soon as possible.
Your Name
Missing required field
Your Comment
Missing required field