Often derived from coconuts (though it doesn’t have to be), medium-chain triglycerides (MCTs) are trendy… But does the science back the hype?

First, the principle

MCTs are commonly enjoyed because unlike short- or long-chain fatty acids, they can be quickly broken down and either immediately converted quickly and easily into energy, or turned into ketones in the case of a surplus (in the case of true excess, however, it’ll simply be stored as fat).

Most of that involves the liver, so for anyone who wants a refresher on liver health:

How To Unfatty A Fatty Liver ← notwithstanding the title, this is also important knowledge even if your liver is healthy now—if you’d like it to stay healthy, anyway!

You can also read about the ins and outs of glycogen metabolism and the body’s energy-based metabolic processes in general (including the body’s energy processes that go on in the liver), here:

From Apples to Bees, and High-Fructose Cs: Which Sugars Are Healthier, And Which Are Just The Same?

If the liver turns the MCTs into ketones, those ketones will then be used for energy if there is insufficient glucose available (as the body will always use glucose from the blood first, if available, before moving to alternative energy sources such as ketones and/or fat reserves.)

Thus, many people look to ketones as a solution for having enough energy to function while on a very low-carb diet such as the ketogenic diet:

Ketogenic Diet: Burning Fat Or Burning Out?

…which as you’ll recall, does work for short-term weight loss, but brings long-term health risks, so should not be undertaken for long periods of time.

So, does MCT Oil help?

With regard to weight loss, the research is weak and mixed:

• Weak, because often the methodology was shoddy, often there are many factors not controlled-for, and often the sample sizes were small (and also, RCTs by their very nature tend to be quite short-term (often 6, 8, or 12 weeks), whereas heavy reliance on ketones from MCTs may fall into the same long-term problems as the ketogenic diet in general).
• Mixed, because the results varied widely (probably because of the aforementioned problems).

Rather than pick at individual studies, let’s look at this review and meta-analysis of 13 studies, with a combined sample size of 749 people (so you can imagine how small the individual RCTs were):

❝Compared with LCTs, MCTs decreased body weight (-0.51 kg [95% CI-0.80 to -0.23 kg]; P<0.001; I(2)=35%); waist circumference (-1.46 cm [95% CI -2.04 to -0.87 cm]; P<0.001; I(2)=0%), hip circumference (-0.79 cm [95% CI -1.27 to -0.30 cm]; P=0.002; I(2)=0%), total body fat (standard mean difference -0.39 [95% CI -0.57 to -0.22]; P<0.001; I(2)=0%), total subcutaneous fat (standard mean difference -0.46 [95% CI -0.64 to -0.27]; P<0.001; I(2)=20%), and visceral fat (standard mean difference -0.55 [95% CI -0.75 to -0.34]; P<0.001; I(2)=0%).

No differences were seen in blood lipid levels.

Many trials lacked sufficient information for a complete quality assessment, and commercial bias was detected.❞

So, if we’re going to take those numbers at face value, that means a net weight loss, over the course of the trial period, was…

*drumroll*

0.51kg (that’s about 1 lb).

To put that into perspective, if you did nothing else but pee 1 cup of urine before getting weighed, you’d register as having lost 0.25kg (or about ½ lb) by virtue of the bathroom trip alone.

Here’s the paper:

Effects of medium-chain triglycerides on weight loss and body composition: a meta-analysis of randomized controlled trials

What about cholesterol and heart health?

With regard to cholesterol, MCT oil is touted as improving blood lipids, which means lowering LDL and increasing HDL (within a safe range, anyway).

You’ll remember that the above review concluded “No differences were seen in blood lipid levels”.

It may again be a case of individual studies cancelling each other out. For example…

This study found that it improved lipids in 40 young women as part of a calorie-controlled interventional diet:

Effects of dietary coconut oil on the biochemical and anthropometric profiles of women presenting abdominal obesity

This study found that it worsened lipids in 17 young men, worse even than taking an equivalent amount of sunflower oil:

Effects of medium-chain fatty acids and oleic acid on blood lipids, lipoproteins, glucose, insulin, and lipid transfer protein activities

In short, it’s a gamble.

It may be good for insulin sensitivity, though

This one seems to be specific to people with type 2 diabetes. The paper heading says it all, but we include the link in case you want to know the details (the short version is, it improved insulin sensitivity in diabetic subjects only (not others), and didn’t affect anything else that was measured:

Dietary substitution of medium-chain triglycerides improves insulin-mediated glucose metabolism in NIDDM subjects

The sample size was small (20 people total, of whom 10 had diabetes), and the next study was with 40 people, this time moderately overweight and all with type 2 diabetes:

Effects of dietary medium-chain triglyceride on weight loss and insulin sensitivity in a group of moderately overweight free-living type 2 diabetic Chinese subjects

Want to try some?

We don’t sell it, but here for your convenience is an example product on Amazon 😎

Enjoy!