MCT: A Complete Guide to Medium Chain Triglycerides
In the 1980s Dr. Vigen K. Babayan, from Harvard?s University Nutrition Laboratory, devised a technique to isolate and create pure MCT oil. 
MCTs are different from long chain triglycerides (LCTs; the most commonly consumed dietary fat in the human diet) in a number of ways. LCTs are 12 to 18 carbon atoms long and have 9 calories per gram whereas MCTs are 6 to 12 carbon atoms long and have 8.3 calories per gram. 
MCTs, compared to LCTs, are more soluble in water, smaller in size, require less energy, and require fewer enzymes to break down.   This means MCTs strain the pancreas less than LCTs and are prioritized in the digestive tract.
At a high level your body breaks down MCTs into individual medium chain fatty acids (MCFAs) which are a more usable and available energy source. Upon consumption MCTs are absorbed directly from the intestine in to the portal vein where they are then transported to the liver and prioritized as an energy source via beta-oxidation.  MCFAs are prioritized over LCFAs because they can enter the double mitochondrial membrane rapidly without the carnitine transport system and do not require binding to fatty-acid proteins.  
Ketones are produced when the body converts MCTs in to a usable energy source. Ketones and glucose are the only two substances the brain can use for energy.
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Recommended MCT Dosage and UseOnce you determine your macronutrient requirements based on your fitness goals you can use MCT oil in place of other fat sources. You may find maximum benefit consuming MCTs before physical activity given their energy-enhancing properties. If you follow dietary protocols like carbohydrate backloading or the ketogenic diet, both of which emphasize high protein/low carb/high fat phases, MCTs are an excellent non-carb source of pre-workout energy.
The research thus far indicates that MCT supplements are extremely safe to stack with other supplements and do not interact with any medications.  You can consume MCTs any time of the day without issue.
MCT BenefitsMCTs can increase fat oxidation, increase energy expenditure, and improve athletic performance. MCT consumption and MCFA oxidation appears to increase body fat oxidation and satiety compared to LCTs, which may expedite fat loss. 
17 obese female subjects consumed a eucaloric diet (re: calories burned = calories consumed) made up of 40% fat, 67% of which was either MCT oil or LCTs (via beef tallow), for 27 continuous days. Researchers found that those consuming MCT oil had a 5.55% higher energy expenditure and 6.67% higher fat oxidation rate. 
A 4-week study of 19 overweight men found that consuming calorie-controlled diet high in MCTs instead of LCT-rich olive oil led to a 66% greater reduction in bodyweight, increased energy expenditure, and increased fat oxidation.  Interestingly those with the lowest starting bodyweights experienced the most dramatic increase in energy expenditure and fat oxidation.  This may indicate overweight men don't respond as well to the benefits of rapidly oxidizing fat sources like MCTs.
When 31 overweight males and females consumed either 18 to 24g of MCT oil or olive oil for 16 continuous weeks, those who consumed MCT oil lost 1.7 more kilograms, lost more total fat mass, trunk fat mass, and intraabdominal fat tissue. 
These findings show that replacing LCTs with MCTs will burn more fat and calories per day if you hold caloric intake constant.
One study attempted to explain how MCTs work and proposed that they decrease fat mass by down-regulating two primary drivers for cell differentiation - adipogenic genes and peroxisome proliferator-activated receptor gamma.6 Regardless, individuals typically consume about 62.5 less calories per day when they eat meals contain high levels of MCTs rather than LCTs. 
Although this may not seem like a large value, over 365 days this adds up to a whopping 22,812.5 calories, or about 6.5 pounds! The type of fat you eat influences your energy expenditure, satiety, and fat burning potential.
Although research on MCTs and athletic performance is limited, mice consuming MCTs outperformed mice consuming LCTs during swimming capacity tests.  This performance discrepancy may partly be due to how the body processes MCTs more like a carbohydrate than a fat, which would increase available short term energy for aerobic activity.
Unlike some fat sources, moderate MCT consumption does not increase cholesterol and triglyceride levels in the blood.  Some research indicates that MCT consumption comprising 12 to 24% of total consumed calories may decrease fasting lipid, glucose, and diastolic blood pressure levels.    Improved lipid levels decreases the risk of serious medical conditions and improved insulin sensitivity decreases the likelihood your body stores excess calories as fat.
MCTs are considered an immunomodulator, which mean they weaken or modulate immune system activity to decrease the inflammatory response.   Other non-fitness-related benefits of MCTs include: improved seizure control, prevention of muscle breakdown in critically ill patients, reduction of tumor size, and treatment of food absorption disorders.  
MCTs offer numerous benefits for both healthy and non-healthy individuals.
MCT Side EffectsExcessive MCT oil consumption, or any oil for that matter, can cause oily stools even in healthy individuals. This shouldn?t cause for alarm but should suggest that perhaps you?re consuming too many liquid fats. The liver is the primary processor of MCTs so if you have liver problems do not use MCTs. 
Ketone production may be desirable for healthy individuals on no-carb, low-carb, or ketogenic diets, but excessive ketone production can be extremely harmful for diabetics.  However, moderate consumption of MCTs may be beneficial for pre-diabetics and diabetics due to the glucose-lowering effects of MCTs.
MCT SupplementsThe most concentrated MCT supplements are coconut oil and pure MCT oil. They are liquid, semi-solid, and capsule form. Tiger Fitness sells the following MCT supplements:
- NOW Foods MCT Oil - $15.49 for 32 fluid ounces (64 servings)
- Twinlab MCT Fuel - $11.59 for 16 fluid ounces (32 servings)
- E-Pharm Organic Extra Virgin Coconut Oil - $12.49 for 16 ounces (32 servings)
- NOW Foods Organic Virgin Coconut Oil - $7.98 for 12 ounces (24 servings)
- NOW Foods Virgin Coconut Oil 1000mg Capsules - $9.39 for 120 capsules (40 servings)
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13) "Immunomodulators." Crohn's & Colitis Foundation of America. N.p., 16 Jan. 2009.
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