Medium chain triglycerides (MCTs) are a type of fatty acid that are found naturally in foods like coconut oil, palm oil, and some dairy products. Because MCTs are shorter in length than long-chain fatty acids (i.e. vegetable oils) and water-soluble, they are metabolized differently in the body. Once absorbed into the bloodstream, MCTs bypass the digestion process of longer chain fatty acids and go directly to the liver where they are rapidly broken down and thus, provide a quick source of energy and are less likely to be stored in fat cells. This is why it is often said MCTs act more like a carbohydrate than a fat.
Benefits of MCTs For Weight/Fat Loss: Multiple studies suggest that substituting MCTs for other fats in a healthy diet may support healthy weight and body composition when combined with exercise. This is due to MCTs:
- Lower energy density: MCTs contain 8.4 calories per gram versus 9.2 calories per gram for long chain fatty acids. Substituting MCTs for other fats may create a calorie deficit and lead to small, but significant changes in body weight.
- Thermic effect: When MCTs are combined with carbohydrates and proteins, there is a significant thermogenic effect that leads to more calories being burned and fewer calories being stored as fat, which in turn may help reduce weight/body fat levels.
- Satiating effect: MCTs may increase peptide YY and leptin to a greater extent than long chain fatty acids. These two hormones help reduce appetite and create a feeling of fullness.
- Aversion to being stored as fat: MCTs are less likely to be stored as fat compared to long chain fatty acids due to being more rapidly absorbed and used as energy in the body.
While many studies have demonstrated MCTs are beneficial for weight/fat loss, other research has found no effects. Additionally, weight loss due to MCT supplementation can vary widely with most clinical trials showing a 1 to a 5-pound loss in weight over periods lasting 3 to 12 weeks. At this point, more studies need to be conducted to determine how effective MCTs are for weight loss and how much should be taken to derive the greatest benefits.
For Athletic Performance: Due to limited studies conducted, the evidence linking MCT consumption to enhanced performance is weak. However, MCTs can still be of benefit to athletes in the following ways:
- MCTs may have a protein and carbohydrate sparing effect within the body since they can be used for energy. This means greater reserves of amino acids to promote growth and recovery and increased glycogen stores to fuel prolonged efforts. In summary, MCTs provide fats in the diet that can be used to support activity or growth without contributing to stored adipose tissue like other fat
- MCTs are a calorie-dense option for athletes who need to gain weight or whose sport has higher energy demands.
- MCTs act as an ideal energy source for those adhering to a ketogenic diet or for individuals trying to cut carbs who want to maintain total daily calories.
For Health: MCT supplementation may also confer some health benefits. These are:
- MCTs have been linked to lower cholesterol levels in both human and animal studies. However, other studies have shown no effect or adverse effects on cholesterol when supplementing with MCTs.
- MCTs may help lower blood sugar and may increase insulin sensitivity. However, more research is needed to confirm these benefits.
- MCTs may improve brain function. Because MCTs produce ketones, they can be used as an energy source for the brain. However, more research is needed to confirm this benefit.
What does the Research Say About Medium Chain Triglycerides? Below is a brief review of the studies linking MCT supplementation to weight/fat loss and performance benefits:
- A 2003 study by St-Onge et al. discovered that subjects who consumed MCTs for 28 days lost more adipose tissue and had increased energy expenditure and fat oxidation levels compared to individuals who consumed long-chain triglycerides. From the results, the researcher concluded that MCTs might aid in the prevention of obesity and stimulate weight loss.
- Tsuji et al. (2001) found individuals who supplemented with MCTs over the course of 12 weeks were able to significantly decrease body weight, overall body fat, and subcutaneous fat compared to a group who consumed long-chain triglycerides.
- Dulloo et al. (1996) discovered relatively low-to-moderate intake of MCTs (15-30 g per day) as part of habitual diet may play a role in the control of human body composition by enhancing daily calorie expenditure.
- Costa (2012) performed a review of 14 articles on short and long term MCT supplementation and found six showed a decrease in body mass of individuals, with consequent loss of weight. One showed a positive effect on satiation (feeling of fullness) and four showed an increase in daily calorie expenditure.
- A 2001 study by Oopik et al. found that runners who supplemented with MCTs for seven days increased the availability of ketone bodies for oxidation in working muscles during high-intensity exercise. The researchers concluded that this could improve performance by prolonging time to exhaustion.
MCT Dosage, Safety, & Side Effects Research seems to indicate that 5-30 grams of MCTs daily are most effective in producing weight loss benefits. More studies need to be conducted to determine the optimal amount to provide (if any) enhancements in performance. At present MCT supplementation has not been reported to have any serious side effects or adverse interactions with medications. Some minor side effects may include nausea, vomiting, diarrhea, and upset stomach. These can be avoided by starting with smaller doses and increasing intake slowly.
Bottom line of MCTs MCTs may have a small, but significant impact on weight and body fat loss. They may also provide some endurance exercise benefits. For these reasons, adding MCTs to your diet may be worth a try. However, more studies need to be conducted on MCTs to further demonstrate these effects.
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