Does MCT Oil Break a Fast?

author avatar Dr. Eric Berg 08/31/2023

Does MCT oil break a fast? Yes, MCTs can slightly break your fast—but not enough to affect your results. Find out why you should start using MCT oil and learn how to integrate it into your Healthy Keto™ and intermittent fasting plan. 

Pure MCT oil in bowl

What are MCTs?

Medium-chain triglycerides (MCTs) are types of fats extracted from certain oils, including palm oil, coconut oil, and many dairy products.

There are four kinds of MCTs

  • C6 (caproic acid)

  • C8 (caprylic acid)

  • C10 (capric acid)

  • C12 (lauric acid)

MCTs absorb quickly in the body because they’re water soluble and have short carbon chains. This allows them to bypass the digestive system and reach the liver, where they are quickly converted into ketones (fuel).

The two most common MCTs are caprylic and capric acid, or C8 and C10. These MCTs have many incredible health benefits while you’re in ketosis, and they’re found in most high-quality MCT products. 

What is MCT oil?

MCT oils are concentrated forms of medium-chain triglycerides. They contain isolated MCTs, unlike coconut oil and dairy products, which also contain long-chain triglycerides that require bile to digest fully.

MCT oil is often used as a supplement to help maximize your results while doing intermittent fasting and a keto diet. It can also be added to vitamin and mineral supplements to increase bioavailability.

Consuming MCT oil while intermittent fasting boosts your ketones. This can help your body more quickly adapt to ketosis, reducing the risk of keto flu symptoms.

Keto and intermittent fasting plan

What is intermittent fasting?

Intermittent fasting is an eating pattern that reduces the number of times you eat and maximizes the amount of time you fast between meals. You have all of your meals for the day within a one- to eight-hour eating window. During your fasting window, you don’t consume any meals, snacks, or beverages with calories. 

Intermittent fasting keeps your insulin level low during your fasting period, which allows your body to tap into stored fat. 

The moment your insulin level spikes—whether it’s a sip of soda or a full meal—your fast is broken. 

Intermittent fasting is an important part of the ketogenic diet. When done correctly, it provides many incredible health benefits. 

Benefits of fasting:

Will taking MCT oil while intermittent fasting break my fast?

MCT oil will not fully break your fast. Unlike carbohydrates and protein, fat has very little effect on the production of insulin—which is the hormone that stops all fasting benefits. MCT oil is pure fat, which doesn’t cause a sharp insulin spike. 

While MCTs will affect your metabolism more than a glass of water or cup of black coffee, the effects are negligible. MCTs will not raise insulin for long enough to reduce the health benefits of fasting. The slight insulin increase is more than made up for by the many incredible benefits of MCT oil.

Weight loss

Benefits of MCT oil

Here are some incredible ways MCT oil can support your health on a keto and intermittent fasting plan.

Reduces keto flu symptoms

If you’re new to Healthy Keto™, MCT oil can help reduce the keto flu symptoms you experience during adaptation, including keto fatigue, headaches, and brain fog.

Improves cognition

MCT oil boosts ketones, which are the brain’s preferred fuel. This helps improve your mental clarity, memory, focus, and overall cognitive function.

Increases energy

MCTs quickly pass through the gut and are absorbed in the liver, where they are converted into ketones, a fast-acting alternative to glucose. Ketones quickly circulate through your body, even bypassing your blood-brain barrier to provide clear and focused mental energy.   

Use MCT oil with your initial meal, coffee, or tea to provide an energy boost that will get you through the rest of the day.

Promotes normal blood sugar

Taking MCT oil helps stabilize blood sugar levels, which is especially helpful for those with diabetes or cardiovascular conditions. 

Reduces appetite

You can take MCT oil while fasting to reduce appetite and cravings during your fasting period, making it that much easier when you are starting an intermittent fasting plan and adapting to ketosis. 

Supports weight loss

MCTs are far less likely to be stored as fat, and they support weight loss better than long-chain fatty acids.

Because it lowers your overall appetite, MCT oil also helps you lose weight by helping you extend your fasting period. The longer you fast, the more time your body has to burn stored fat. 

Increases exercise performance

MCT oil rapidly increases ketones, which can boost your energy, endurance, and muscle function during exercise—especially in your fasting window. They also naturally reduce cramps caused by the buildup of lactic acid in your muscles.

MCT oil vs. coconut oil while fasting

MCT oil vs. coconut oil

MCTs are among several different kinds of fats found within coconut oil. In fact, most MCT oils are extracted from coconut oil.

The biggest difference between them is that MCT oil provides 100% MCTs, while coconut oil has a mix of long-chain and medium-chain fatty acids.

They are also metabolized differently—MCT oil is digested and absorbed quickly, while coconut oil has more complex fats that take more time to break down.

Coconut oil is a natural source of MCTs—they make up 54% of the total fat content. However, coconut oil also contains long-chain triglycerides, which require enzymes and bile to break down and absorb. 

How much MCT oil should you have while fasting?

Always start slow and increase your intake over time. You can experience digestive troubles or abdominal cramps if you take too much MCT oil at once. 

Half a teaspoon is a good starting point. You can slowly increase to a tablespoon over the course of several days and work up to four tablespoons a day as your body adapts. 

If you have a thin build and you want to maintain your weight level, you can use four tablespoons of MCT oil a day. MCT oil is calorie-dense—so if you’re trying to lose weight, you should lower your MCT oil intake after keto-adaptation.

Salad dressing with MCTs

How to use MCT oil on keto

There are many ways you can add MCT oil to your diet or as an ingredient in your favorite keto-friendly treats. Here are six great ways you can start using it today.

Consume it straight

MCT oil is virtually odorless and flavorless—so you can have it on its own while you’re fasting. Have a tablespoon if you start experiencing hunger or cravings while fasting.

Add it to coffee and tea

A great way to add MCT oil to your routine is to mix it into your coffee or tea. Not only is it an easy and enjoyable way to consume it, but it’s also an excellent way to boost your mental clarity and energy throughout the day.

Take it before workouts

Taking MCT oil 30 minutes before a workout can increase your exercise performance. Your body quickly absorbs the MCTs, supplying your muscles with energy, reducing the formation of lactic acid, and improving your endurance.

Add it to salad dressings

A simple and healthy way to include MCT oil in your diet is to add it to salad dressings. Vegetables carry fat-soluble phytonutrients that are more easily absorbed when you consume them with healthy fats. Though it won’t add any flavor, using MCT oil on your salad will help boost its nutritional value.

Use it as a healthy oil replacement

In addition to salads, you can also use MCT oil for cooking meals, particularly if you want to sauté a dish. Remember to cook with it at or below 320 degrees F so it doesn’t burn.

Take it with fat-soluble vitamins

Fat-soluble vitamins—including vitamins A, D, E, and K—are more easily absorbed when consumed with healthy fats. Taking MCT oil along with these vitamin supplements will boost their bioavailability. 

MCT oil coffee recipe

This delicious keto coffee is similar to a latte. It has a nice creamy texture but without the carbs and protein found in steamed milk. Give it a try!

MCT oil coffee

Time: 5 minutes 


Per Serving: 230 calories, 0 grams protein, 0 grams carbohydrates, 25 grams fat 


  • 1 cup preferred black coffee blend, brewed

  • 1 to 2 tsp MCT oil

  • 1 to 2 Tbsp grass-fed unsalted butter


  1. Add coffee, MCT oil, and butter into a blender.

  2. Blend together for 20 to 30 seconds until mixed well.

  3. Pour into a cup and enjoy!

Tip: You can add turmeric, cinnamon, cocoa powder, sea salt, or chili powder to enhance the flavor and add additional health benefits to your MCT oil coffee

Key takeaways

Consuming MCT oil has a slight effect on your intermittent fast. The benefits of having MCT oil far outweigh these minor effects—it helps you fast for longer, lose weight, stay energized, maintain normal blood sugar levels, and restore insulin sensitivity. It’s also a great way to help your body adapt to ketosis in the early stages of Healthy Keto. 

MCT oil is an excellent addition to meals, salads, tea, and coffee. It’s flavorless and odorless, so you can have it as a supplement along with your vitamins. Always start with a small amount of MCTs and gradually increase your intake to give your body time to adjust. 

For more interesting ways to use MCT oil, check out our recipe page.


Can MCT oil help me lose weight?

Yes, MCT oils can reduce cravings for carbs between meals, helping you extend your fasting period and stay in ketosis. It’s also far less likely to be stored as body fat compared to long-chain triglycerides. 

Can too much MCT oil while fasting slow down weight loss?

Yes. Consuming too much MCT oil can affect your weight loss because your body will always prioritize using dietary fat before tapping into stored body fat during intermittent fasting. 

Does MCT oil kick you out of ketosis?

No, using MCT oil will not kick your body out of ketosis. 

Does MCT oil put you in ketosis faster?

Yes, the increase of ketones provided by consuming MCTs can jumpstart ketosis. 

Can I take MCT oil on an empty stomach?

Yes, you can take MCTs on an empty stomach. Start with half a teaspoon and increase your intake to one to four tablespoons. 

What time should I take MCT oil?

MCT oil can be taken at any time of day, morning, noon, or night. You can also have it with your nutritional supplements to enhance their bioavailability.

Will bulletproof coffee break my fast?

Bulletproof coffee can somewhat break your fast. It can interrupt the process of fat burning for a short time. Keep in mind that your body will use the ketones it gets from the MCT oils in the coffee rather than those it produces from fat burning—which can slow down weight loss if you have too much.

Does coconut oil contain MCTs?

Yes, coconut oil contains both medium-chain triglycerides and long-chain triglycerides.

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