For the longest time, fitness gurus and media outlets demonized dietary fat, claiming that it is harmful to our health, and leads to all sorts of problems down the line.
But, as research grew, we became aware of two important facts:
Not all dietary fats are created equal and, if we want to stay healthy and function optimally, we need to include some fat in our diet.
This mindset shift has opened the doors for even more research to be conducted, which has helped shape the public opinion of fat for the better.
One particular type of dietary fats, medium-chain triglycerides (MCT), has been gaining a lot of attention in recent years, and many folks believe it to be a vital nutrient for good health and plentiful gains.
But how true is that? Let’s find out.
What Are Medium-Chain Triglycerides, and What is MCT Oil?
A small preface:
Triglyceride is the scientific term for fat molecules (1). Each triglyceride is made of three fatty acid molecules, bound together by a glycerol molecule (2). Going a bit deeper than that, and we come to the composition of each fatty acid – strings of carbon atoms, mixed with oxygen and hydrogen atoms (3).
Depending on the composition, fatty acids come in four categories (4):
- Short-chain triglycerides (SCT) – those which contain two to five carbon atoms.
- Medium-chain triglycerides (MCT) – those which contain six to twelve carbon atoms.
- Long-chain triglycerides (LCT) – those which contain thirteen to twenty-one carbon atoms.
- Very long-chain triglycerides (VLCT) – those which contain twenty-two or more carbons.
For the sake of simplicity, we’ll go over the first three categories and ignore the fourth.
Short-chain triglycerides are derived when dietary fiber gets broken down by bacteria in the colon (5). SCTs are thought to offer numerous health benefits to us, primarily the prevention of colorectal cancer later in life (6).
Long-chain triglycerides are the most common form of fatty acids in foods. A popular example here is omega-3 fatty acids (DHA and EPA), which are abundant in fatty fish and chia seeds (7). Omega-6 fatty acids are another example, and rich sources of them include eggs and some vegetable oils (8).
Medium-chain triglycerides can be found in a handful of foods, namely, coconut and palm oil, as well as full-fat dairy products (9).
MCT oil is a liquid made entirely of medium-chain triglycerides, which are commonly derived from coconut or palm oil. The liquid is usually tasteless, odorless, and colorless (like water), but it can also be brown-ish.
Below is Thomas DeLauer. He is a proponent of MCT Oil use. He makes a good argument. Watch this video to get his take.
MCT Oil For Fat Loss: Does It Make a Difference?
This is where things get interesting. Spend half an hour looking up information on the topic, and you’re bound to come across dozens of elaborate theories and possible mechanisms of action. All of them sound great on paper, and you can bet that each promises a lot to us.
For example, there’s an interesting theory which states that MCT oil directly accelerates fat loss. Would you look at that? Unlike normal fats (that need to be packed into lipoproteins, enter our lymphatic system, and then go into the bloodstream), MCTs are directly absorbed into the portal vein and are sent directly to the liver (10).
In other words, MCTs bypass the digestive system and are instead shuttled into the mitochondria (often referred to as the power generators of our cells, as they convert oxygen and nutrients into usable energy – ATP molecules) for the creation of energy (10).
The primary argument here is that MCTs are preferentially used for energy rather than for fat storage. And, yes, research on triglyceride metabolism supports this argument – the body doesn’t preferentially store MCTs (10). But, there’s a keyword here: preferentially – that doesn’t mean that they can’t get stored as fat under the right circumstances.
As you probably know, the primary requirement for fat gain is an energy surplus (11). In other words, eating more calories than you burn over weeks and months. So long as you do that, your body will store excess calories as fat, and some of the medium-chain triglycerides will likely be part of the process.
Another thing worth looking at here is how the body uses the four macronutrients once we ingest them. When it comes to protein and ethanol (alcohol), the body preferentially breaks them down and uses them for energy right away, as it doesn’t have effective mechanisms for storing them for later use – especially not alcohol (12, 13).
Despite what many gurus and keto zealots suggest, carbohydrates are similar in that regard, as the body preferentially uses them for two things (14):
1) As an immediate source of energy for the body and brain.
2) As a source to replenish lost muscle and liver glycogen.
Once these requirements are met, the body can start converting sugars into fats through a process known as lipogenesis (14). Still, the process is rather inefficient, and the body prefers to go another route:
Storing dietary fats for later use.
But before we go on, I can’t stress this enough:
You will not accumulate body fat unless you’re also eating in a caloric surplus. The mere consumption of fats is not what makes us gain fat, so always keep that in mind.
With that said, if your body doesn’t need to burn dietary fats for energy (for example, if there are also plenty of proteins and carbs in your system), it will preferentially store them for later use, as the process is much easier and more efficient.
MCTs act slightly different from SCTs and LCTs in that they are usually burned off for energy first. But medium-chain fatty acids can still contribute to overall fat gain if you’re in a caloric surplus (15).
The last thing worth looking at here are the findings of one study from 1990 (16). In it, researchers compared the effects of long and medium-chain triglyceride consumption (in combination with a caloric surplus). What they found was interesting:
1) Increased fatty acid synthesis either from acetate or from chain elongation of C8 and C10 fatty acids is energetically costly and would result in a lesser efficiency of storage of ingested MCT-derived energy as depot lipid compared to deposition of energy from LCT.
2) This scheme is consistent with our previous finding that MCT overfeeding results in a greater increase in postprandial energy expenditure than LCT overfeeding.
3) The inefficient storage of diet-derived MCFA relative to LCFA might suggest that MCT would be useful in helping control body weight.
In simpler terms, yes, MCTs are more difficult to be stored as fat and could potentially help with bodyweight control, especially given the fact that they cause a greater thermic effect when compared to LCTs. But, as the researchers noted:
However, it must be noted that significant de novo lipogenesis would not be expected to occur with MCT incorporation into diets fed at restricted or maintenance levels, and under such conditions, MCT and LCT might produce similar thermogenic responses. Yost and Eckel reported that an 800 kcal/day diet containing 24% of calories as MCT did not lead to greater weight loss than an isocaloric diet containing LCT.
In other words, the hype surrounding MCT for fat loss doesn’t hold much water, and what matters most is being in a caloric deficit if your goal is to get leaner. Under these circumstances, MCTs won’t make much of a difference when compared to LCTs.
MCT Oil and Cardiovascular Health: Friend or Foe?
Some sources go as far as to suggest that MCTs and MCT oil directly improve cardiovascular health. On the one hand, that sounds intriguing. But, on the other, it seems like something impossible, right? After all, we’ve been told that fats are inherently bad for us, and now, suddenly, we are told the exact opposite thing.
One argument here is that MCT oil helps lower cholesterol levels. This idea largely stems from a study that was published in 2007 (17). In it, forty overweight subjects with type 2 diabetes were given 18 grams of MCT oil or corn oil (rich in LCTs) daily for three months.
Researchers found that the subjects who were given MCT oil saw a reduction in LDL (bad) cholesterol and an increase in HDL (good) cholesterol. Subjects in that group also experienced an involuntary reduction in energy intake, and weight loss, unlike the corn oil group. Han JR et al. concluded:
Collectively, our results suggest a link between moderate consumption of MCT and improved risk factors in moderately overweight humans in a low-cost, free-living setting.
But because the MCT oil group also saw some weight loss, we can’t be certain how big of a role (if any) medium-chain triglycerides played for these benefits. This could simply be a result of weight loss.
Another study we’ll be looking at today is one from the distant 1990 (18). In it, subjects were overfed with either MCT- or LCT-containing foods over six days. Researchers found:
1) a reduction in fasting serum total cholesterol concentrations with the LCT, but not the MCT diet; and 2) a threefold increase in fasting serum triglyceride concentrations with MCT, but not LCT, diet.
The last interesting study worth looking at came from Tholstrup et al. and was published back in 2004 (19). In it, the researchers had 17 young men replace the majority of their fat intake either with 70 grams of MCT oil or 70 grams of high-oleic sunflower oil. In both cases, subjects followed these protocols for three weeks with a two-week washout period in-between.
Researchers looked at the following parameters: total cholesterol, LDL, VLDL (similar to LDL, and has been associated with cardiovascular disease), HDL, triglycerides, and blood glucose levels (20). When compared to the three weeks of sunflower oil ingestion, the MCT oil intervention was not kind. Subjects had:
- 11% higher plasma total cholesterol
- 12% higher LDL cholesterol
- 32% higher VLDL cholesterol
- 12% higher ratio of LDL to HDL cholesterol
- 22% higher plasma total triacylglycerol
- higher plasma glucose
Indeed, consuming 70 grams of MCT oil per day is likely to screw your health up in major ways.
So, where do we stand on MCT oil for cardiovascular health? Well, it’s too early to say for sure, as we need more research. But, it appears that the overconsumption of MCTs can negatively impact our health.
MCT Oil For Ketone Production?
With the rise of keto dieting in the last few years, gurus and marketers took advantage of the hype and began pushing MCT oil as an essential part of low-carb dieting. The idea is, MCT oil is a crucial player for ketone production, and not supplementing with it undermines your dietary efforts.
Like most confidently-made statements, this one also seems to make sense on paper. But how true is it?
Well, it’s been well-established that ketones are produced in the liver through the breakdown of dietary and body fat (21). And it’s also true that some fats, including MCTs, are more readily converted to ketones. As we established earlier, MCTs are absorbed into the portal vein and are sent directly to the liver, where they can aid in ketone production if need be (10). But whether or not that leads to some greater benefit in the real world is yet to be established.
We know that ketogenic dieting doesn’t lead to superior fat loss when compared to a normal calorie-restricted diet, so a temporary rise in ketone production thanks to MCT oil likely doesn’t help us get leaner (22).
With that said, there could be a small ergogenic benefit to MCT oil consumption on a keto diet, but, again, we don’t have any research to back up this hypothesis at the moment.
Can MCT Oil Help Us With Our Bodybuilding Efforts?
Another common idea floating around these days is that MCT oil helps with bodybuilding. Being a rapidly-digested source of fat, it’s no surprise that folks add all sorts of labels to the supplement.
But, for the most part, research so far doesn’t suggest that MCT oil supplementation aids with muscle growth.
One promising mechanism here is that MCT oil potentially increases athletic performance. The idea is, being able to perform a bit better in the gym leads to slightly larger training volumes, which itself can help us gain a bit more muscle over time.
The only question is, how reliable is this ergogenic effect?
Well, as far as positive results go, one study so far has seen a benefit to MCT supplementation for swimming endurance (23). But the study is more than two decades old. And it was done on mice…
Trials that were done on humans either didn’t see a benefit or saw a decrease in athletic performance (which, to be honest, is a bit surprising). Perhaps the most notable paper on the topic comes from Miriam Clegg, Ph.D., who took the time to review a lot of data.
The title says it all. In it Clegg concluded:
Results indicate that MCT feeding is ineffective in improving exercise performance and future work should focus on the health benefits and applications of MCT.
I was a bit curious as to why MCT oil would hinder exercise performance, seeing as MCTs are digested rapidly and contribute to ATP production. As it turns out, five of the studies Clegg reviewed concluded that MCT oil reduced athletic performance because it caused GI distress.
In the context of strength training, MCT oil supplementation doesn’t appear to benefit our performance or muscle-building potential. If anything, it can cause a drop in performance due to possible stomach distress.
MCT Oil For Energy And Brain Function: Are There Any Pre-Workout and Nootropic Benefits?
In addition to all of the other claims, marketers, and gurus out there often push MCT oil as an agent that boosts our energy, well-being, and cognitive function.
The idea is, thanks to the unique ability of medium-chain triglycerides to effectively bypass the digestive system and go to the liver quickly, they must help provide the brain with the fuel it needs to function well.
With the risk of being the bearer of bad news, I respectfully disagree with this notion. First of all, consuming some nutrients (whether that’s protein, fats, or carbs) likely doesn’t have an immediate benefit for your cognitive function. The reason is, your brain is very unlikely to go low on energy in the short-term, so consuming more nutrients with the idea of giving your brain extra fuel to work with is misguided.
The fact is, even if calories are restricted, your body can break down muscle and fat tissue to get the energy and nutrients it needs to sustain itself and keep the brain well-fed.
Second, we also need to remember that glucose is the primary source of energy for the brain, not triglycerides (24). To function properly, the body has its ways of producing enough glucose for the brain, even if you’re otherwise on a low-carb or ketogenic diet.
Finally, it’s also worth pointing out that, though MCTs metabolize fairly quickly, they are an inefficient source of immediate energy, especially when compared to simple sugars and essential amino acids.
In other words, we don’t have any research to support the claim that MCTs can, in any way, boost our energy levels and cognitive function. What’s more, this argument doesn’t seem to make much sense from a mechanistic standpoint, and all we have are some optimistic speculations and not science-backed statements.
MCT Oil Dosage: Where Do We Stand On That?
With everything we covered today, it appears that we need more research before concluding on the efficacy of MCT oil. The results from studies are inconclusive at best, and the potential benefits should be taken with a heaping spoon of salt.
Still, if you are interested in trying MCT oil for yourself and see how it works for you, here are some recommendations.
- Start with a small dose of about one teaspoon (5 ml or so) per day for at least one week to see how well you can tolerate it.
- If you tolerate it well and don’t notice any GI distress, you can increase the dose to two teaspoons per day, preferably spaced out by a few hours.
- After the second week, you can increase the dose to a single tablespoon (about 15 ml) per day.
With that said, it’s important to remember that MCT oil is a source of pure fat, and thus has a lot of calories. For example, a single teaspoon contains about 5 grams of fats, which is roughly 45 calories. A tablespoon has about 15 grams of fats, which is roughly 135 calories.
It’s by no means diet-breaking, but it’s something to keep in mind.
Are There Any Side Effects And Drawbacks to MCT Oil Supplementation?
For the most part, if you abide by the above recommendations and don’t have a particularly sensitive stomach, you should be completely fine. Some side effects that have been seen in studies include nausea and indigestion (25).
It’s also worth noting that these side effects are more likely to occur if a larger dose is taken at once – like, for example, having a tablespoon of MCT oil.
Other than that, MCT oil appears to be safe. The only thing to keep in mind is that some research suggests that MCT oil might increase LDL (bad) cholesterol and blood triglyceride levels (18, 19). This is something to keep in mind in the long run, even though we need more research in this area.
And, because MCT oil is calorie-dense, you should count its calories to your daily total. Otherwise, you might find yourself struggling to shed fat if you’re dieting, or even gain some unwanted weight.
The Bottom Line on MCT Oil Supplementation
There are a couple of unwritten rules in the world of sports supplementation and fitness:
1) If it sounds too good to be true, it probably is.
2) Whenever a new supplement comes out of nowhere and takes the fitness world by storm, you should be very skeptical of its efficacy.
MCT oil, unfortunately, appears to check both of these rules off. There is no shortage of promises of what it can deliver, but research doesn’t seem to agree.
At its core, MCT oil is nothing more than a source of isolated fats. And while gurus and marketers love to make sensational claims, research disagrees:
- MCT oil doesn’t appear to help with weight loss or satiety.
- It doesn’t appear to improve cardiovascular health. In fact, some research suggests the opposite.
- It doesn’t improve athletic performance or lead to more muscle growth. In fact, it may impair performance by causing stomach distress.
- It doesn’t improve cognition or increase our energy levels.
So, at least for the moment, I maintain the opinion that MCT oil is one supplement we can go without. It appears to be yet another overpriced and overhyped product that is nothing more than a substitute to other natural oils.
My Personal Experience with MCT Oil
When i started the research for this article, I was a proponent of MCT Oil use.
I have used MCT Oil myself many times over the years. This fall and winter I did a slow bulk and gained 30 lbs. To help get in my calories, I mixed 1 TBSP of MCT Oil in with my daily protein shake.
I have also used MCT Oil pre-workout to hopefully get more out of my training.
When writing an article, I search for scientific studies that have definite results. I couldn’t find any that suggested MCT Oil had any benefits.
After writing this, I will just eat some extra almonds next time I want to add fat to my diet and I’ll eat some extra carbs to improve my training.
If you still want to try MCT Oil for yourself, I have used Left Coast Performance MCT Oil in the past. It seems to be of good quality and is cost effective.
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