Does MCT Oil Break a Fast?

What will you learn from the article?

How does the MCT ketogenic diet work?

MCTs are absorbed more efficiently than long-chain fats and are transported directly to the liver, where they are converted into ketones. Ketones are an alternative energy source that the body can use when glucose levels are low. The increased production of ketones in the MCT ketogenic diet is what leads to its therapeutic effects.

Benefits of the MCT ketogenic diet

The MCT ketogenic diet may be better tolerated than the classic ketogenic diet due to the increased allowance of carbohydrates and protein. For instance, studies conducted by Dr. Elizabeth Neal and colleagues have shown that the MCT ketogenic diet is equally effective as the classic ketogenic diet in controlling seizures. MCT oil or MCT powder can be incorporated into various foods and recipes, even if you´re fasting.

What Are Fasting and Intermittent Fasting?

Fasting can be defined as a complete or partial abstinence from food for a specified period. It has been a common religious and spiritual practice for milenia. Intermittent fasting is a dietary pattern that cycles between periods of fasting and eating. 

The main idea of the ketogenic diet and intermittent fasting is to make you a more efficient fat burner. When we restrict carbohydrates the body loses its access to the glucose it usually uses to make ATP. Then, it starts using more and more fat as a fuel. As a byproduct of fat metabolism, the liver produces ketones, little molecules that help the mitochondria to function better.

Both the ketogenic diet and fasting promote weight loss, correction of insulin resistance, and mitochondria repair, potentially increasing longevity. There are many methods of intermittent fasting, such as:

• Alternate-day fasting: fasting every other day. It is one of the ways to trigger autophagy, a cellular process that helps remove damaged cells and promote cellular repair. It is considered extremely challenging for most people.
• 5:2 diet: allows normal consumption of calories for 5 days a week and restricts calories to 500-600 calories a day for 2 days a week. It allows for flexibility in food choices on the non-fasting days, but results in terms of weight loss, and improved metabolic health will depend on the quality of foods chosen. Although less challenging than alternate-day fasting, sustainability in the long term is a concern.
• Time-restricted feeding: limits eating to a specific window of time each day. It is the most popular time of fasting and you can start fasting between 12 and 16 hours a day. Doing so your insulin levels will be more stable. It is known that high insulin levels are associated with several potential problems.

In any of the methods above fasting will accelerate the process of ketosis. As fats are burned in the absence of carbohydrates, ketone bodies accumulate and can be identified in the blood or urine. Fasting is a recommended strategy for those who want to shed extra weight, improve metabolic health, and reduce the risk of chronic diseases.

But, try to track your body composition during the process. Fasting for too long can lead to the muscles being used as a source of energy. This affects your health in the long term, as muscles are essential for a good metabolism. One possible strategy to facilitate fasting without wasting your muscles is using MCTs. The MCT ketogenic diet was designed to stimulate the metabolism even during fasting. MCTs will allow you to maintain the fat-burning state over an extended period of time.

What Is MCT Oil and How Is It Used?

MCT oil has gained significant popularity as a dietary supplement, often touted for its potential benefits for weight loss and overall health. The MCT ketogenic diet is a variation of the classic ketogenic diet that uses medium-chain triglycerides (MCTs) as a fat source. As MCTs are easier for the body to absorb and use than long-chain fats, it allows the MCT diet to have a lower overall fat content while still providing the benefits of ketosis. This can make the MCT diet more tolerable for some people, especially those who find the classic keto diet too restrictive.

MCT’s have several properties that make them very useful in the keto diet:

• Rapid Absorption: Due to their shorter chain length, MCT oils are more rapidly absorbed by the body compared to LCTs. This is because they bypass the lymphatic system and enter the bloodstream directly, providing a quicker source of energy.  
• Ketogenic Potential: MCTs can promote a ketogenic state, where the body primarily uses fat for fuel instead of carbohydrates. This can be beneficial for weight management and certain health conditions.  
• Energy Source: MCTs are a concentrated source of energy and can be used as a fuel source for various activities.  

Clinical, scientific and dietetic evidence suggests that inclusion of MCTs as a source of fat in the diet not only promote and enhance ketogenesis, but as provide a potential anti-epileptic effect, enhance dietary palatability and acceptability, is helpful in the management of constipation.

Common Sources of MCTs:

• Coconut Oil: Contains a high percentage of MCTs, primarily lauric acid.  
• Palm Kernel Oil: Another good source of MCTs, with a slightly different fatty acid profile than coconut oil.

MCT Oils and powders: A refined product that is extracted from coconut or palm kernel oil and is composed primarily of MCTs. 

How Does MCT Oil Impact the Biochemistry of Fasting?

MCTs are a type of triglyceride, a molecule composed of glycerol and three fatty acids. 

    Illustration 1: Structure of triglycerides (Mills, Hall, & Berry, 2017)

Unlike long-chain triglycerides (LCTs), which are more common in dietary fats, MCTs have fatty acid chains that are shorter (6 to 12 carbon atoms).  

           Illustration 2: Description of fatty acids of various lengths (Jandacek, 1994)

MCTs are emulsified in the gut lumen, where gastrointestinal lipases hydrolyze them to Medium chain fatty acids (MCFAs). MCFAs are absorbed directly into the portal vein and, unlike LCT, are not packaged into lipoproteins. In the liver, MCFAs are quickly oxidized, whereas the fate of LCFAs is dependent on the metabolic state of the organism. 

LCFAs is the predominant fat present in food. Concentrated animal and plant sources of LCT such as butter, vegetable oils and double cream, typically supply LCFAs to the diet. They are transported to the mitochondria for oxidation using CPT1. When conditions favor fat storage, malonyl-CoA is produced as an intermediate in lipogenesis. Malonyl-CoA inhibits CPT1, and prevents oxidation of LCFAs in the mitochondria. MCFAs enter the mitochondria without the use of CPT1 and are not subject to the regulations that control the oxidation of LCFAs. Because MCFAs enter the liver rapidly and are quickly oxidized, a large oral dose of MCT will result in higher levels of ketones. 

Illustration 3: Metabolism of MCTs versus LCTs (Constantini et al., 2008)

Does MCT Oil Affect Autophagy During Fasting?

On the contrary! Autophagy is a cellular process that involves the breakdown and recycling of cellular components. It plays a crucial role in maintaining cellular health, especially during fasting or nutrient deprivation. Overall, MCTs can be seen as autophagy enhancers during fasting. Their ability to stimulate autophagy may contribute to the health benefits associated with MCT consumption, such as weight management and improved metabolic health.

Here’s how MCTs can positively impact autophagy:

• Increased AMPK Activation: MCTs can activate AMP-activated protein kinase (AMPK), a key regulator of cellular energy metabolism. AMPK activation promotes autophagy by inhibiting mTOR (mammalian target of rapamycin), a protein that suppresses autophagy. Research also shows that AMPK activation leads to increased mitochondrial biogenesis and improved exercise performance (Wang et al., 2018).

Illustration 4: Effects of MCTs on exercise (Wang et al, 2018)

• Enhanced Ketone Body Production: MCTs can be metabolized into ketones, which can further stimulate autophagy by activating AMPK and inhibiting mTOR.
• Direct Autophagy Induction: Some studies suggest that MCTs may directly induce autophagy, independent of their effects on AMPK and mTOR.

Will MCT Oil stop fasting benefits?

Technically, any caloric intake breaks fast. However, when getting to the liver, MCTs are rapidly converted to ketones, sustaining ketosis, which is the main goal of the fasting state. An investigation from Columbia University compared two groups of overweight people eating a diet with the same number of calories. One group received supplemented MCTs and lost more weight even though oils are caloric (Lei et al., 2012).

Although a tablespoon of MCT oil will add around 100 kcal to your diet, it will not diminish your results of fasting. So, if you need to add MCT oil to your drinks go for it. A tablespoon is enough to achieve a blood ketone level that improves metabolism (Mumme, & Stonehouse, 2015) as MCTs are more likely to be used for energy rather than being stored as fat. C8 MCT oil, specifically, is often used in intermittent fasting due to its rapid absorption and potential for enhanced ketone production.

What if I feel bad during fasting?

Metabolic changes start happening in the body as it does not have as much access to glucose. Some people feel more irritability, lethargy, muscle soreness, or trouble concentrating for a few days. It is called keto flu. It is a temporary phase as the body adjusts. It is important to take a keto electrolyte and include in your diet foods that are high in magnesium (avocados, broccoli, kale, pumpkin seeds), potassium (asparagus, avocados, tomatoes, leafy greens), and calcium (sardines, sesame, and chia seeds).

Meanwhile, you may hydrate yourself, with water, coffee, teas, sugar-free electrolytes (ketolytes), exogenous ketones, while keeping up with your MCTs. You can also start slower, fasting only on the weekends when you will probably be able to sleep and rest more.

When starting MCT ketogenic diet always start on low amounts of MCT and build up. Spread the MCT supplement out throughout the day with each meal or snack. That will produce higher increments of ketones throughout the day. If you have stomach upsets avoid taking MCTs on its own. You may incorporate the oil or powder into your preparations such as muffins, baked eggs, gravies, soups, or beverages.

Bilbiography