To Your Health

Q. A trainer where I work out has recommended a supplement called MCT oil. He says it will improve athletic performance and help with weight loss. How can increased fat in the diet help with weight loss?

A. MCT (medium chain triglycerides) oil, sometimes called "thin oil," is not your typical fat. Most fat is composed of fatty acids with a "long chain" of 14-22 carbons, while MCT fatty acids are 6-12 carbons. The difference in the number of carbons makes a world of difference in what happens to MCT in the body.

MCTs occur in small quantities (up to 15%) in a variety of foods such as coconut oil and breast milk. Pure MCT is a "designed" fat, commercially manufactured from coconut oil. Because of the short carbon chain, MCTs are rapidly absorbed and transported directly to the liver where they are converted to energy. This makes them metabolically more similar to carbohydrates than to other fats. MCTs have very little tendency to be stored as body fat.

Originally developed in the 1950s, MCTs are still used for people who require assistance in absorbing fat, such as AIDS and cancer patients, and children with cystic fibrosis. Especially when combined with pancreatic enzymes, MCTs are easily digested and absorbed, providing needed energy for people in delicate health, and as a bonus they do not contribute to heart disease.

Some of the recent claims for MCT oil, such as those advanced by your trainer, will require more research. Some research indicates that MCT promotes fat burning, increases metabolic rate, increases muscle mass, and improves endurance athletic performance. If MCT accomplishes some of these goals, it may indeed help with weight loss.

Most people believe that the only way to lose weight is to eat less or exercise more. This notion omits a very important factor: the basal metabolic rate (BMR). The BMR is the rate at which calories are burned to maintain life, calories we burn even while resting. One reason why over 90% of weight loss diets eventually fail is that the body tends to lower the BMR when calories are reduced. Thus when a person goes off the low calorie diet and back to a normal eating pattern, calorie requirements are still reduced and weight is gained on a diet that formerly would maintain a constant weight.

Fat tissue contributes very little to the BMR compared to muscle. Increasing muscle mass and reducing fat will increase BMR, and exercise does exactly that, but MCT may aid in the process. If so, it would indeed be worthwhile to include MCT in a weight loss program. Except for diabetics, MCT appears to be safe in amounts up to 50 grams per day (about three tablespoons).

It is always important to give your body all the nutrients it needs to be healthy. Trying to lose weight only by reducing calories will usually reduce nutrient intake also, but weight loss programs that enable you to raise your BMR allow you to raise your caloric (and therefore your nutrient) intake. If MCT can assist in this process, it can be a valuable addition to your weight loss program.