MCFAs are very easy for your bodyto metabolize. In fact, your body prefersto burn MCFAs for energy rather
thanconverting them to stored body fat. Sofar in this series we’ve covered the di-gestion, absorption, and metabolism ofCapTri® and conventional dietary fats.We’ve also explained the reasons whyconventional fats make you fat butCapTri® does not. Whereas regular fatsare circulated throughout the body and areprone to be stored as body fat, CapTri® istransported directly to the liver where itis immediately burned to produce energy(1).
Conventional dietary fats have thesame molecular structure as body fat, soit’s easier for your body to store them.Metabolism of conventional fats isa lot of work for your body (as you’venoticed on the stair climber) and in gen-eral your body will go to the trouble toburn these fats as your carbohydratesources are depleted. CapTri®, while be-ing a fat, has a different molecular struc-ture from the fat stored on your body:The fatty acid chains are shorter (1). Asit turns out, this results in CapTri® beingvery easy for your body to metabolize,and your body prefers to burn CapTri®for energy rather than converting it to theform of storage fat (1). If eating regularfood is like throwing a log on the fire,then eating CapTri® is like pouring gaso-line on the fire. Since CapTri® burns sofast, it has very little tendency to be storedand that is the reason it’s so popular withbodybuilders. The calories from CapTri®can be used to fuel activity or to supportweight gain. Athletes add CapTri® to theirfood to provide additional calories andmake drinks out of CapTri® to use whilethey train. Some endurance athletes evenuse it while they’re running.We explained that CapTri® is me-tabolized in liver mitochondria. Mitochon-dria are little furnaces inside cells and arethe site of cellular energy production. Mi-tochondria are sometimes referred to as“the powerhouse of the cell.” As youknow, the body produces energy from thefoods we eat by combining the foods withoxygen from the air we breathe.
This typeof chemical reaction is called “oxidation”because it involves reaction with oxygenand is very similar to burning things in afire. Many oxidation reactions releaseenergy, just like a fire does. The maindifference between burning something ina fire and inside your body is that the en-ergy of a fire is released as heat to thesurroundings. When foods are burned in-side the body, some of the energy is cap-tured so it can be used by the body. Thisprocess of burning foods occurs in themitochondria, and the energy is capturedby a molecule called ATP. ATP is the di-rect source of energy used for all bodilyfunctions, including muscle contraction.Before the energy contained in foods canbe used by the body, it has to be con-verted into ATP.Unfortunately, body fat and conven-tional dietary fat cannot enter the mito-chondria by themselves because the fatmolecules can’t make it across the mito-chondrial membrane (2). These fatmolecules have to be actively carriedacross the membrane by the carnitineshuttle. If carbohydrate fuels are available,this transport system is not very active (2).This is why your body burns fat only af-ter carbohydrates have been depleted andis one of the reasons why fat tends to bestored so easily.
In contrast, CapTri®, withits small molecular structure, can get intothe mitochondria by itself and doesn’tneed the carnitine shuttle (1,2). Thismeans that CapTri® is burned immedi-ately— at the same time as carbohydrates(3). This additional energy source has acarbohydrate-sparing effect (4).What happens to CapTri® insideliver mitochondria? If CapTri® is burnedin the liver, how can the energy get to mymuscles? Here’s how:Once inside the mitochondria, allfats are burned in a process called beta-oxidation. In beta-oxidation, blocks oftwo carbon atoms at a time are choppedoff the end of the fatty acid chain. Thisforms an intermediate called “acetyl-CoA” which then enters an energy-pro-ducing pathway known as the “Krebscycle.” The products of the Krebs cyclethen enter the “electron transport chain”which generates our old friend ATP,as thechart above shows.All of this occurs inside the mito-chondria. What happens with CapTri® isthat it gets burned in the liver so fast thatit makes an enormous amount of acetyl-CoA, and the Krebs cycle can’t keep upwith it all. In other words, the Krebs cyclecan only make ATP so fast, and CapTri®can overwhelm it. So what happens is thatsome of the acetyl-CoA gets diverted to adifferent metabolic fate—conversion toketone bodies (1).This process is termed “ketogen-esis”— which simply means the manufac-ture of ketones. What happens is two mol-ecules of acetyl-CoA combine to makeone molecule known as a ketone body, orsimply a ketone.
This process occurswith regular fats too. Your body producesketones from your body fat while fast-ing. Under normal conditions, however,regular dietary fats do not produce manyketone bodies because they’re not burnedthat fast. The Krebs cycle can keep upwith it and turn all the acetyl-CoA intoATP. But CapTri® —and not regularfats—will still produce ketone bodies ifcarbohydrates are ingested at the sametime (3). This indicates two things: thatCapTri® is burned at the same time as car-bohydrates, and that CapTri® is burnedreally fast.So, a significant proportion of theCapTri® molecules are converted into ke-tone bodies in the liver. These are releasedinto the bloodstream and are taken up bymuscles to be used for energy (1). In themuscle cells the ketones are convertedback into acetyl-CoA and are further me-tabolized to generate ATP, as outlined.This explains what happens to CapTri®inside liver mitochondria, how it is con-verted into energy, and how this energy istransported to the muscles to be used.One interesting point about ketonebodies is that they are readily excreted inthe urine – unlike fatty acids or glucose.So any extra calories which are not usedas fuel can be eliminated instead of beingconverted into fat.
Add that to your listof reasons why CapTri® is not stored asfat.CapTri® , unlike conventional di-etary fat, is burned very quickly in theliver, producing acetyl-CoA. Part of thisis converted to ATP in the Krebs cycle.The remainder, which is a significant por-tion, is converted to ketones which travelfrom the liver to the bloodstream to themuscles where it is converted to energy.You can see that CapTri®, as asupplement to your daily diet, providesyour body with the energy-producing calo-ries used in metabolic processes by be-ing converted to ketones which are useddirectly by the muscles as energy. Ketonescan also be excreted by the body whennot used, therefore not being convertedto bodyfat. Simply put, using CapTri® isone of the most efficient ways to get yourbody the energy it needs for desired results.
1. Bach and Babayan, Medium chain trig-lycerides: an update. Am. J. Clin. Nutr.36: 950-962 (1982).
2. Record, Kolpek, and Rapp, Long chainversus medium chain length triglycerides- a review of metabolism and clinical use.Nutr. Clin. Prac. 1:129-135 (1986).
3. Sucher, Medium chain triglycerides: areview of their enteral use in clinical nu-trition. Nutr. Clin. Prac. 44: 146-150(1986).
4. Cotter, Taylor, Johnson, and Rowe, Ametabolic comparison of pure long chaintriglyceride lipid emulsion (LCT) and vari-ous medium chain triglyceride (MCT)-LCT combination emulsions in dogs. Am.J. Clin. Nutr. 45: 927-939 (1987).