Coconut oil is widely promoted for weight-loss, but while the promises of coconut oil's benefit sound great, the research is less clear.
A few studies have looked at the benefit of coconut oil on weight loss, and results have been mixed. Though some studies have reported a decrease in participants' body mass index (BMI) and waist size, others have not. All of the studies have been short-term. And it's important to note that the better designed studies have evaluated coconut oil as part of a reduced-calorie diet and exercise plan. There is no evidence that coconut oil will have a beneficial effect on weight loss if you simply add it to your diet.
Coconut oil is from the dried fruit (nut) of the coconut palm tree. Although it's called an oil, it's essentially solid at room temperature, more like the texture and consistency of vegetable shortening. Coconut oil is nearly 100 percent fat, and 82 to 92 percent of that is saturated fat. One tablespoon of coconut oil contains 11 grams of saturated fat.
All fats are not the same
Fats can be characterized as saturated or unsaturated. Saturated fats can be further divided into short-, medium- and long-chain fatty acids. These types of fats have different effects in the body. Unlike long-chain fatty acids, medium-chain fatty acids are absorbed directly into the bloodstream. They don't raise blood cholesterol as much as long-chain fatty acids do, and they don't appear to be stored in the body's fat tissue as readily as long-chain fatty acids are.
Coconut oil has been of interest because it contains both medium-chain and long-chain fatty acids. The primary component, however, is lauric acid. Based on its structure and function, lauric acid lands in the middle, behaving in some ways like a medium-chain fatty acid and in others like a long-chain fatty acid.
Many studies of medium-chain fatty acids and health benefits have been conducted with manufactured oils – derived in part from coconut oil or other plant oils – that don't contain lauric acid. Therefore, it's important not to draw conclusions about the benefits of coconut oil based on studies with oils called medium-chain triglyceride (MCT) oils.
Other research findings
Researchers have also looked at the effect of coconut oil on blood cholesterol levels. Coconut oil appears to raise low-density lipoprotein (LDL) cholesterol – the "bad" cholesterol – but not as much as foods that contain long-chain fatty acids, such as meat or full-fat dairy products. Some studies show that coconut oil may increase high-density lipoprotein (HDL) cholesterol – the "good" cholesterol – but whether this has a beneficial effect on heart disease is not known.
The entire body of evidence regarding dietary fats still supports the use of unsaturated oils, such as olive, canola, safflower or sunflower oil, instead of saturated fats or coconut oil for the management of cardiovascular risk factors.
Coconut oil also adds calories to your diet, about 120 calories per tablespoon of coconut oil, which is why it will likely not aid weight loss if it's not used with a calorie-controlled diet and physical activity.
The bottom line
Research about the potential benefits of coconut oil asks important questions, but it's too soon to draw clear conclusions. More research is needed with larger study groups and long-term follow-up to understand the impact of coconut oil on weight loss, blood cholesterol, and cardiovascular risk factors. And those results will need to be compared with the overall body of information about nutrition and health.
Although eating coconut oil in moderation isn't going to result in great harm to your health, it's not likely to help you lose weight either. If you enjoy the flavor of coconut oil, use it sparingly as part of an overall healthy dietary pattern. For successful, long-term weight loss, stick to the basics – regular physical activity and an overall calorie-controlled, healthy-eating plan rich in fruits, vegetables and other plant products.