Effects of Medium-Chain Triglycerides on Weight Loss and Body Composition: A Meta-Analysis of Randomized Control Trials
Karen Mumme et al. (2014)
About Medium Chain Triglycerides (MCT):
Medium Chain Triglycerides (MCT) are becoming a popular supplement in the weight loss, health and performance industry. Briefly, MCT differ to other types of fatty acids and contain 8 to 12 carbon atoms and include caprylic acid, capric acid and lauric acid. This unique composition of MCTs is proposed to counteract fat depositions in the adipocytes via an increase in thermogenesis and possibly aid in satiety. Due to MCT only being found in a few whole foods, such as coconut oil (58%), palm kernel oil (54%), desiccated coconut (37%) and raw coconut meat (17%) many people supplement with whole MCT oil.
The present meta-analysis aimed to investigate the current data on the use of MCT oil on weight loss and body composition in adults. Changes in blood lipid levels were also assessed as a secondary outcome. Studies lasting 3 weeks or more were included, up until 2014.
Results of the Meta-Analysis:
Out of the 13 trials, when comparing the use of MCTs against Long Chain Triyglycerides (LCT) they found MCT further decreased several markers such as total body weight, waist circumference, hip circumference, total body fat, total subcutaneous fat and visceral fat with no change in blood lipid levels.
Despite these positive changes, the percentage change witnessed was only small, demonstrating the need for more long-term, controlled research. Further, as with any meta-analysis, caution must be made when summarizing the overall results due to factors such as the study designs and commercial bias potentially skewing the results. One major issue with the present meta-analysis is the varied difference in MCT dosing levels, which varied from as little as 2g to 54g per day.
One Study Found a Decrease in Fat Loss Despite No Change in Diet or Calorie Intake:
In one study by St-Onge et al. (2003) they utilized a high dose MCT strategy (54g per day) for 27 days in obese women. This study also closely controlled macronutrient and total daily energy intake (by providing set meals) which was a confounding variable of most studies included in this meta-analysis. After 27 days there was no shift in total or subcutaneous fat volume, however they did not see an increase in Energy Expenditure. Although this study was short, in isocaloric conditions the replacement of MCT for LCT could promote greater fat loss or reduce fat accumulation.
In summary, the use of MCT may make a slight difference to body composition over the long-term; however, based on the current evidence the use of MCT may provide greater benefit in markers of health and disease. For weight loss, fundamentals such as daily energy balance, protein intake and exercise likely play a much greater role, so more controlled research in isocaloric and macronutrient matched conditions is needed for MCT.
With that being said, the shift towards the use of less LCT and more MCT can only be positive for long-term health in general society. When selecting your dietary fats you should try to have a mix of different types. The best sources include Olive Oil, Nuts & Seeds, Red Meat, Avocado, Coconut Oil. If on a low-carb or ketogenic diet I would definitely recommend a higher MCT fat intake. Many people also use MCT oil pre workout for energy, especially when on a low-carb diet.