A recent meta-analysis published in the March-April 2015 issue of the Journal of the American College of Nutrition found that the replacement of long-chain saturated fats (mostly animal fats) with 5 grams of Medium Chain Triglycerides (found in coconut and palm oil) over at least four weeks led to losses of:
- 1.5lbs total weight
- 1.96lbs body fat
- 0.7 inches from waist circumference (1).
Saturated fats are highly diverse, contrary to historical coverage by researchers and the media. There are over thirty different saturated fats that are sub-categorized by the length of carbons in their chemical structure. They are segregated into short-chain, medium-chain, and long-chain fatty acids.
Long-chain saturated fats are what we typically think of when we think of “saturated fats” and their roles in metabolism and health. These are most commonly found in animal fats.
Short-chain and medium-chain fats share a distinct metabolism from the long-chain saturated fats, and even have differing caloric values when digested. Medium-chain fats include capric acid, caprylic acid, and lauric acid - predominantly found in coconut oil, and related supplements.
Unique Health Benefits of MCTs
Medium-chain fats are considered to be thermogenic or “calorie-burning” (2), are metabolized as fast as glucose (3; 4; 5), and also promote the creation of unique energy molecules known as ketones (6). Ketones are the only other source of energy aside from sugar that the brain and nervous system can use for energy. Ketogenic diets may be helpful for epilepsy, weight control, exercise, and malabsorptive disorders (5; 7; 8). MCT metabolism is likened to that of complex carbohydrates - supplying energy over a long period of time as opposed to the quick burst you see with simple carbohydrates.
Medium-chain triglycerides are also anti-microbial - meaning they have been shown to deactivate certain viruses, bacteria, fungi and molds (9). When digested, most of the MCT’s are turned into ketones or re-esterified into “inactive” fatty acids. A small portion are turned into medium chain monoglycerides such as monolaurin, monocaprin, or monocaprylin.
The monoglycerides are what are ultimately responsible for the systemic antimicrobial effects of MCT’s. Chronic low-level toxemia from toxins released from chronic infections may complicate weight loss efforts due in part to their effect on healthy thyroid function. Aside from their unique metabolism, MCTs may assist weight loss by easing the communication between thyroid hormones and thyroid receptors in the body.
Some chronic underlying infections such as Human Herpesvirus-6 (HHV-6) are implicated in autoimmune thyroid disorders as well (10). Reducing the viral load of such triggers may also assist thyroid health. Monolaurin may help reduce viral load from HHV-6 and other similar viruses such as Epstein-Barr Virus, Cytomegalovirus, Herpes Simplex Virus-1 and 2, and more. Monolaurin has also been shown to kill Candida albicans which has been long-implicated by wellness professionals in thyroid health and weight balance.
Coconut Oil and Weight Loss
Intake of MCTs can be improved by consuming 1-3 tablespoons of coconut oil per day (providing mostly lauric acid, but also capric and caprylic acid), as well as supplementing with monolaurin or MCT oil (caprylic and capric acid) directly.
So while the recent meta-analysis is promising for the use of MCTs and their counterparts in weight loss and management efforts, more robust studies are needed to further prove or disprove the evidence. As you can tell by the modest results, this is not a "lose weight fast" scam. The authors are careful to note that the data is still a little weak to be making serious health claims based on the study's findings. In short, your food choices and exercise level are still important.
The important take-away is that MCTs are very unique compared to other fats - and this finding is under-appreciated by the media, health professionals, and researchers alike.
But given the unique metabolism of MCTs, and their unique immune effects, it is not surprising that in as little as four weeks, substitution of long-chain saturated fats with 5g of MCTs led to modest improvements in weight (1.5lbs), body fat (1.96lbs) and waist circumference (0.7in) have been found using these fats compared to long-chain saturated fats.