Medium-Chain Triglycerides Effect Weight Loss

Medium-chain triglycerides (MCT) are a unique kind of dietary fat that lend a wide range of positive health benefits, weight loss among them. MCT’s have a fatty acid chain length that varies between six and twelve carbon atoms, which is only one characteristic that distinguishes them from the more familiar long-chain fatty acids, such as the highly-celebrated fish oil. MCT’s are transported through the blood by the portal system, which bypasses the usual route of digestion and sends them directly to the liver.

Medium-chain triglycerides do not require the modifications of long-chain and very-long-chain fatty acids.  Neither do they require bile salts for digestion.  These qualities enable them to be less susceptible to hormone-sensitive lipase and to deposition into adipose (fat) tissue storage.  A study from England’s Oxford Brookes University in 2010 announced that, because of their particular character, “MCT’s have been researched for both benefits to exercise performance and health.”  In the former application, MCT’s may be “a means to maximizing an athlete’s ability to maintain their glycogen stores so they can be more competitive.”  From the health angle, these substances “increase fat oxidation and energy expenditure as well as reduce food intake and beneficially alter body composition.”  (Clegg. 2010)

If you watch the lose-weight ads on TV, you might be driven to buy one of the untested, unproven, and maybe even unsafe products that promise the physique of champions.  Read the small print to learn that exercise and diet are part of the program, and your dreams of Roman god-hood (or goddess) are shattered.  Back to the chips and dip, right?  There might be something that’s been tested, and found to be safe and effective for at least a little drop in weight.

Because MCT’s don’t need energy for absorption, utilization or storage, they’ve been used to treat malabsorption conditions.  But weight management has evoked more interest.  The milks from humans, dogs, and guinea pigs contain mostly long-chain fats.  Those from goats, cows, and sheep are primarily short-chain.  Horse milk has lots of medium-chain fatty acids.  Data suggest that the milk of all species depends on a partial resynthesis of pre-formed glycerides. (Breckenridge. 1967)  (Since horses run faster than cows, their milk is hard to bottle, and because they have only two spigots, it takes longer to get it.)

Decades ago, MCT’s had been studied for body fat management in obese persons without diabetes, but more recent work has focused on those with Type 2 diabetes.  The findings showed that a diet containing MCT’s at 18 grams a day (about 2/3 ounce) brought about a reduction in body weight and waist circumference, a decrease in insulin resistance, and a drop in serum cholesterol concentration.  (Han. 2007)  Compared to the subjects ingesting long-chain fatty acids, the results are significant.  The MCT users also enjoyed increased dietary satiety, meaning that they felt full sooner, so they ate less.  Still another welcome benefit was realized by a cohort in 2009, when Chinese investigators noted a significant decline in serum triglycerides and LDL-cholesterol, both markers for cardiovascular complications, in those ingesting 25-30 grams (there are 28 grams in an ounce) of MCT’s a day. (Zhang. 2009).  (Xue. 2009)

The fast rate of oxidation of medium-chain fatty acids leads to greater energy expenditure—almost without doing any hard work.  It’s impressive that such can be the case, especially where weight gain is reduced and the size of body fat deposits diminishes.  Note that fat cells are not normally lost once they appear; they merely shrink in size.  They are, however, prepared to expand again at the drop of a hat.  (Xue. 2009)

Since the 1960’s MCT’s have been advocated for use in weight control.  Back then the research entailed other factors as well, including  the balance of energy intake, the nature of the diet, the ratio of MCT to LCT (long-chain triglycerides), and duration of the protocol.  Nonetheless, the presence of MCT’s as part of the regimen made a difference.  Although the exact mechanism hasn’t been fingered, MCT’s are able to increase energy outgo, hasten satiety at the table, and facilitate weight control when consumed as a replacement for fats containing LCT’s.  ( St-Onge. 2002)  Increased heat production, known as thermogenesis, is one of the activities by which MCT’s burn fat. (Baba. 1982)

Palm oil and coconut oil are major food sources of medium-chain fats.  The fact that these are saturated fats means little because all sat fats are not created equal, displaying differing cholesterolemic effects.  Therefore, when you see them listed on an ingredient label, have no fear.  The less weight you need to lose, the faster you will see results, so it’ll pay to get started now. (St-Onge. 2003)

MAIN ABSTRACT Clegg ME. Medium-chain triglycerides are advantageous in promoting weight loss although not beneficial to exercise performance. Int J Food Sci Nutr. 2010 Nov;61(7):653-79.

SUPPORTING ABSTRACTS W. C. Breckenridge and A. Kuksis Molecular weight distributions of milk fat triglycerides from seven species The Journal of Lipid Research. September 1967 (8): 473-478.

Han JR, Deng B, Sun J, Chen CG, Corkey BE, Kirkland JL, Ma J, Guo W. 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. Metabolism. 2007 Jul;56(7):985-91.

Zhang YH, Liu YH, Zheng ZX, Wang J, Zhang Y, Zhang RX, Yu XM, Jing HJ, Xue CY, Wu J. .   

Xue C, Liu Y, Wang J, Zhang R, Zhang Y, Zhang J, Zhang Y, Zheng Z, Yu X, Jing H, Nosaka N, Arai C, Kasai M, Aoyama T, Wu J. Consumption of medium- and long-chain triacylglycerols decreases body fat and blood triglyceride in Chinese hypertriglyceridemic subjects. Eur J Clin Nutr. 2009 Jul;63(7):879-86.

Marie-Pierre St-Onge and Peter J. H. Jones Physiological Effects of Medium-Chain Triglycerides: Potential Agents in the Prevention of Obesity1 J. Nutr. March 1, 2002; 132(3): 329-332

Baba N, Bracco EF, Hashim SA. Enhanced thermogenesis and diminished deposition of fat in response to overfeeding with diet containing medium chain triglyceride Am J Clin Nutr. 1982 Apr;35(4):678-82.

St-Onge MP, Jones PJ. Greater rise in fat oxidation with medium-chain triglyceride consumption relative to long-chain triglyceride is associated with lower initial body weight and greater loss of subcutaneous adipose tissue. Int J Obes Relat Metab Disord. 2003 Dec;27(12):1565-71.

Clegg ME. Int J Food Sci Nutr. 2010 Nov;61(7):653-79. Medium-chain triglycerides are advantageous in promoting weight loss although not beneficial to exercise performance