Yes, drinking Bulletproof Coffee will break a fast as you will be consuming calories from either the butter, ghee or MCT oil. While it may not affect ketosis, it does provide calories, which can interrupt fasting benefits. Black coffee, on the other hand, is generally accepted as not breaking a fast due to its low calorie content.

Coffee being splashed out of a cup of coffee
If you’re a fan of intermittent fasting and bulletproof coffee, you may be wondering if this popular beverage breaks your fast.
Last Updated: 24 September 2023

Intermittent fasting has become a popular way to manage weight and improve overall health, but it can be challenging to stick to a fasting routine.

Many people experiment with different methods to make the fasting process easier, including drinking beverages like bulletproof coffee.

But, does bulletproof coffee break a fast? We go look deeper around the discussions still happening.

Understanding Intermittent Fasting

Intermittent fasting has become increasingly popular in recent years as a diet strategy that involves alternating periods of eating and fasting.

The concept of fasting is not new, as it has been practiced for centuries in many cultures and religions. However, the scientific community has recently taken an interest in the health benefits of intermittent fasting.

The most common approach to intermittent fasting is the 16:8 method, which involves fasting for 16 hours and eating during an 8-hour window. During the fasting period, you can consume water, black coffee, or tea without any added sugar or creamer. This method is easy to follow and fits well into most people’s lifestyles.

What is the Science Behind Fasting?

The benefits of fasting go beyond just weight loss. Fasting has been linked to numerous health benefits, including improved insulin sensitivity, reduced inflammation, and increased longevity.

When you fast, your body goes into a state of nutritional ketosis, which means that it starts burning stored fat for energy instead of glucose. This can lead to significant weight loss over time.

Fasting also triggers autophagy, a cellular process that involves the breakdown of old and damaged cells. This process might help reduce the risk of chronic diseases like cancer and Alzheimer’s. Additionally, fasting has been shown to reduce oxidative stress, which is a major contributor to aging and disease.

What Are the Different Types of Fasting?

In addition to the 16:8 approach (also known autophagy fasting), there are several other types of intermittent fasting that you can try.

The 5:2 approach involves eating normally for 5 days and restricting calories to 500-600 on 2 non-consecutive days.

Alternate day fasting involves fasting every other day, while the 24-hour fast involves fasting for a full day once or twice a week.

It’s important to note that fasting is not for everyone, and you should talk to your doctor before starting any new diet or exercise regimen. Some people may experience negative side effects like headaches, dizziness, or fatigue during the fasting period.

What Are the Benefits of Intermittent Fasting

The benefits of intermittent fasting are numerous and have been backed up by scientific research.

In addition to weight loss, fasting can also lead to better insulin sensitivity, which can reduce the risk of type 2 diabetes. Fasting has also been linked to improved cognitive function and memory, as well as reduced chronic inflammation.

Intermittent fasting is not a magic solution for weight loss or overall health, but it can be an effective tool when combined with a healthy diet and regular exercise. It’s important to listen to your body and make sure that you are getting enough nutrients and hydration during the eating window.

What is Bulletproof Coffee?

Bulletproof coffee is a hot coffee beverage that has gained popularity in the keto diet and biohacking communities due to its unique combination of mold free coffee, grass-fed butter/ghee, and MCT oil.

It was created by Dave Asprey, the founder of Bulletproof, a company that promotes a high-fat, low-carb diet. Dave claims that bulletproof coffee can help you lose weight, improve cognitive function, and increase energy levels.

What Are the Origin of Bulletproof Coffee

The origins of bulletproof coffee can be traced back to Dave Asprey’s trip to Tibet. During his trek, he discovered the benefits of adding butter and MCT oil to coffee. He found that the mixture provided sustained energy, mental clarity, and reduced hunger cravings.

After returning home, Dave began experimenting with different coffee blends and types of butter and oil. He eventually developed the recipe for bulletproof coffee that is now widely used and enjoyed by many.

Ingredients and Nutritional Content

A typical bulletproof coffee recipe includes:

  • 1-2 cups of coffee
  • 1-2 tablespoons of grass-fed butter
  • 1-2 tablespoons of MCT oil

The use of grass-fed butter is important in bulletproof coffee as it contains butyrate, a fatty acid that can improve gut health and reduce inflammation. MCT oil is a type of fat that is absorbed quickly by the body and can provide a quick source of energy.

It is important to note that bulletproof coffee is a high-fat beverage and should be consumed in moderation. A single serving can contain up to 400 calories and 40 grams of fat.

Potential Health Benefits

While bulletproof coffee has not been extensively studied, some of the potential health benefits include:

  • Increased energy levels: The combination of caffeine, butter, and MCT oil can provide sustained energy and mental clarity throughout the day.
  • Appetite suppression: The high-fat content of bulletproof coffee can reduce hunger cravings and help you stick to your fasting routine.
  • Improved digestion: The butyrate in grass-fed butter can improve gut health and reduce digestive issues such as bloating and constipation.
  • Assist weight loss: The high-fat, low-carb nature of bulletproof coffee can help you lose weight by promoting a state of ketosis, where the body burns fat for fuel instead of carbohydrates.
  • Improved brain function: The combination of caffeine and MCT oil can improve cognitive function and focus, making it a popular choice for those looking to boost productivity.

It is important to note that while bulletproof coffee may have potential health benefits, it should not be used as a replacement for a balanced and nutritious diet. It is always best to consult with a healthcare professional before making any significant changes to your diet or lifestyle.

How Does Bulletproof Coffee Affects Fasting

The incorporation of bulletproof coffee into an intermittent fasting routine is a highly debated topic amongst health experts and enthusiasts.

Some believe that the calories and fat content in bulletproof coffee can disrupt the fasting process and negate its benefits, while others argue that bulletproof coffee can help individuals prolong their fasts and reduce hunger pangs.

The Role of Calories in Bulletproof Coffee and Fasting

From a calorie-restriction standpoint, bulletproof coffee does break a fast as it contains calories from fat. When the body consumes calories, it breaks the fasted state and begins to use the energy provided from the food instead of mobilizing stored fat energy. This means that the body will not be able to reap the full benefits of fasting, such as improved insulin sensitivity and increased fat burning.

However, it is important to note that the number of calories in bulletproof coffee is relatively low compared to a full meal. So, if you are consuming bulletproof coffee during your fasting period, you may still be able to achieve some of the benefits of fasting.

The Impact of Fats in Bulletproof Coffee and Fasting

The fat content in bulletproof coffee can keep you feeling full and prevent you from breaking your fast too early. This can be beneficial for those who struggle with hunger cravings during their fasting period.

Additionally, the fats in bulletproof coffee are primarily medium-chain triglycerides (MCTs), which are quickly metabolized by the liver and converted into ketones. You can measure your ketone levels to see if you are not in ketosis after a Bulletproof Coffee.

Ketones are a type of molecule that the body can use for energy instead of glucose. When the body is in a state of ketosis, it can burn fat for fuel, which can lead to weight loss and other health benefits.

The Impact of Bulletproof Coffee on Autophagy

Autophagy is a cellular process that is triggered by fasting, and some argue that the consumption of bulletproof coffee can disrupt autophagy.

Autophagy is the body’s way of cleaning out damaged cells and recycling cellular components. It is thought to have anti-aging and anti-inflammatory effects.

However, there is not enough research on the topic to draw definitive conclusions. Some studies have shown that consuming small amounts of fat during a fast may not significantly impact autophagy, while others suggest that even a small amount of calories can disrupt the process.

It is important to remember that the benefits of fasting are not solely dependent on autophagy. Fasting has been shown to improve insulin sensitivity, reduce inflammation, and promote weight loss, even if autophagy is not triggered.

In conclusion, the incorporation of bulletproof coffee into an intermittent fasting routine is a personal choice that should be based on individual goals and preferences. While bulletproof coffee may break a fast from a calorie-restriction standpoint, it can also provide benefits such as increased satiety and the production of ketones. The impact of bulletproof coffee on autophagy is still unclear, but fasting can provide numerous benefits even without triggering this cellular process.

Expert Opinions on Bulletproof Coffee and Fasting

Experts in the field have varying opinions on the use of bulletproof coffee during intermittent fasting.

Proponents of Bulletproof Coffee During Fasting

Some experts believe that the consumption of bulletproof coffee can provide numerous benefits during a fast, including improved satiety, mental clarity, and reduced hunger cravings. Additionally, bulletproof coffee may help individuals prolong their fasting periods, allowing them to reap more health benefits.

Detractors of Bulletproof Coffee During Fasting

Other experts argue that the consumption of bulletproof coffee can negate the benefits of fasting as it breaks the fasted state and provides energy from sources other than stored fat. Additionally, consuming bulletproof coffee may interfere with autophagy, a cellular process that is triggered by fasting and involved in numerous health benefits.


So, does bulletproof coffee break a fast? While technically it does because you consume calories it is still a highly debated topic amongst health experts and enthusiasts. You will find some people use of bulletproof coffee during their intermittent fasting protocols.

While it can provide benefits such as improved satiety and energy levels, the calorie and fat content in bulletproof coffee can break the fasted state and prevent individuals from mobilizing stored fat energy.

Ultimately, it is up to individuals to experiment with different methods and determine what works best for their body and fasting routine.

Gary Kirwan

Gary Kirwan

Founder and Host of BioHackers Lab Podcast

Been interested in biohacking concepts and products since first testing what it is like drinking butter in my coffee years ago. My ultimate goal is healthy aging through exercise, diet, social interaction and psychology.