There are several ways that MCTs may help with weight loss, including:
- Lower Energy Density: MCTs provide around 10% fewer calories than LCTs, or 8.4 calories per gram for MCTs versus 9.2 calories per gram for LCTs (10) .
- Increase Fullness: One study found that compared to LCTs, MCTs resulted in greater increases in peptide YY and leptin , two hormones that help reduce appetite and increase feelings of fullness .
- Fat Storage: Given that MCTs are absorbed and used more rapidly than LCTs, they are less likely to be stored as body fat .
- Burn Calories: Studies in animals and humans show that MCTs (mainly C8 and C10) may increase the body’s ability to burn fat and calories .
- Greater Fat Loss: One study found that an MCT-rich diet caused greater fat burning and fat loss than a diet higher in LCTs. However, these effects may disappear after 2–3 weeks once the body has adapted .
- Low-carb Diets: Very low-carb or ketogenic diets are a effective ways to lose weight. Given that MCTs produce ketones, adding them to your diet can increase the number of carbs you can eat while staying in ketosis .
Bottom Line: MCTs may aid in weight loss through reduced calorie intake, increased fullness, less fat storage, improved calorie burning and increased ketones on low-carb diets.
Do MCTs Actually Cause Weight Loss?
While many studies have found positive effects of MCTs on weight loss, other studies have found no effects.
In a review of 14 studies, 7 evaluated fullness, 8 measured weight loss and 6 assessed calorie-burning.
Only one study found increases in fullness, while 6 studies found reductions in weight and 4 found increased calorie burning
In another review of 12 animal studies, 7 reported a decrease in weight gain and 5 found no differences. In terms of food intake, 4 detected a decrease, 1 detected an increase and 7 found no differences .
In addition, the amount of weight loss caused by MCTs is actually very modest.
A review of 13 studies found that on average the amount of weight lost on a diet high in MCTs was only 1.1 lbs (0.5 kg) over 3 weeks or more when compared to a diet high in LCTs .
Another study found that a diet rich in medium-chain triglycerides resulted in a 2-lb (0.9-kg) greater weight loss than a diet rich in LCTs over a 12 week period .
Further high-quality studies are needed to determine how effective MCTs are for weight loss and what amounts need to be taken to experience benefits.
Bottom Line: A diet high in medium-chain triglycerides may help with weight loss, although the effect is generally quite modest.
Evidence for MCTs Enhancing Exercise Performance is Weak
MCTs are thought to increase energy levels during high-intensity exercise and serve as an alternative energy source, sparing glycogen stores.
This may positively affect endurance and have benefits for athletes on low carb diets
One animal study found that mice fed a diet rich in medium-chain triglycerides did much better in swimming tests than mice fed a diet rich in LCTs
Additionally, consuming food containing MCTs instead of LCTs for 2 weeks resulted in longer duration of high-intensity exercise among recreational athletes
Although the evidence seems positive, there are not enough studies available to confirm this benefit, and the overall link is weak
Bottom Line: The link between MCTs and improved exercise performance is weak and more studies are needed to confirm these claims.
Other Potential Health Benefits of MCT oil
The use of medium-chain triglycerides and MCT oil has been associated with several other health benefits.
MCTs have been linked to lower cholesterol levels in both animal and human studies.
For example, calves consuming MCT-rich milk had lower cholesterol than calves fed LCT-rich milk
Several studies in rats have linked coconut oil to improved cholesterol levels and higher antioxidant vitamin levels
A study in 40 women found that consuming coconut oil along with a low-calorie diet reduced LDL cholesterol and increased HDL cholesterol, compared to women consuming soybean oil
Improvements in cholesterol and antioxidant levels may lead to a reduced risk of heart disease over the long term.
However, it is important to note that some older studies report that MCT supplements had no effects or even negative effects on cholesterol
One study in 14 healthy men reported that MCT supplements negatively affected cholesterol, increasing total cholesterol and LDL cholesterol .
Bottom Line: Diets high in MCT-rich foods like coconut oil may have benefits for cholesterol levels. However, the evidence is mixed.
MCTs may also help lower blood sugar levels. In one study, diets rich in MCTs increased insulin sensitivity in adults with type 2 diabetes
Another study in 40 overweight individuals with type 2 diabetes found that supplementing with MCTs improved diabetes risk factors. It reduced body weight, waist circumference and insulin resistance .
However, evidence for the use of medium-chain triglycerides in diabetes is limited. More research is needed to determine its full effects.
Bottom Line: MCTs may help lower blood sugar levels by reducing insulin resistance. However, more research is needed to confirm this benefit.
MCTs produce ketones, which act as an alternative energy source for the brain and can therefore improve brain function.
Recently there has been more interest in the use of MCTs to treat or prevent brain disorders like Alzheimer’s disease and dementia .
One major study found that MCTs improved learning, memory and brain processing in people with mild to moderate Alzheimer’s disease. However, this was only effective in people containing a particular gene, the APOE4 gene .
Overall, the evidence is limited to short studies with small sample sizes, so more research is needed.
Bottom Line: MCTs may improve brain function in people with Alzheimer’s disease who have a particular genetic make-up. More research is needed.
Other Medical Conditions
Because MCTs are an easily absorbed and digested energy source, they’ve been used for years to treat malnutrition and disorders that hinder nutrient absorption.
Conditions that benefit from medium-chain triglyceride supplements include diarrhea, steatorrhea (fat indigestion) and liver disease. Patients undergoing bowel or stomach surgery may also benefit.
Evidence also supports the use of MCTs in ketogenic diets treating epilepsy
The use of MCTs allows children suffering from seizures to eat larger portions and tolerate more calories and carbs than on classic ketogenic diets
Bottom Line: MCTs are effective at treating a number of clinical conditions including malnutrition, malabsorption disorders and epilepsy.
Dosage, Safety and Side Effects
MCT oil appears to be safe for most people.
It is not clear what dose is needed to obtain potential health benefits, but many supplement labels suggest 1–3 tablespoons daily.
There are currently no reported adverse interactions with medications or other serious side effects.
However, some minor side effects have been reported and include nausea, vomiting, diarrhea and an upset stomach.
These can be avoided by starting with small doses, such as 1 teaspoon, and increasing intake slowly. Once tolerated, MCT oil can be taken by the tablespoon.
Type 1 Diabetes and MCTs
Some sources discourage people with type 1 diabetes from taking medium-chain triglycerides due to the accompanying production of ketones.
It is thought that high levels of ketones in the blood may increase the risk of ketoacidosis, a very serious condition that can occur in type 1 diabetics.
However, the nutritional ketosis caused by a low-carb diet is completely different than diabetic ketoacidosis, a very serious condition caused by a lack of insulin.
In people with well-controlled diabetes and healthy blood sugar levels , the amount of ketones remain within a safe range even during ketosis.
There are limited studies available that explore the use of MCTs in type 1 diabetes. However, some have been conducted with no harmful effects .