In today's oversaturated wellness world, there are as many types of oils out there as there are milk alternatives. Alongside coconut and olive oils, one trendy option you might come across is "MCT oil." Many people, particularly proponents of the bulletproof diet and lifestyle, claim that consuming MCT oils can increase energy, while also reducing cravings for food. Some people put MCT oil directly into bulletproof coffee or on top of salads, while others take MCT supplements.
What, you ask, is MCT oil? MCT stands for "medium-chain triglycerides," and it's essentially a type of fat, explains Kris Sollid, RD, a registered dietitian and senior director in nutrition communications at the International Food Information Council Foundation. "Triglycerides are a type of fat that are made up of a glycerol molecule and three fatty acids," he says. Fatty acids come in different lengths of "chains": short, medium, or long. "Medium-chain triglycerides refers to saturated fatty acids that are six-to-12 carbons in length," he says. To get technical, they're called caproic acid, caprylic acid, capric acid, and lauric acid, he says. When you see "MCT oil" sold in bottles, it's MCTs that have been extracted from another type of oil, like coconut oil.
Although MCT oil is often marketed and manufactured as a wellness product, MCTs are traditionally used in a clinical setting for a variety of reasons, Sollid says. For example, MCTs can be used as part of treatment for gastrointestinal disorders that affect the body's ability to absorb dietary fat (such as celiac disease or even diarrhea), he says. However, given that MCTs are more easily digested than other types of fat that we eat, "consuming too much of it at one time has the potential to cause discomfort, cramping, gas, bloating, and yes, even diarrhea," he says. So, you have to be careful not to overdo it — especially if you're putting it in coffee, which is also known to increase people's urge to go, he says.
In addition to these GI uses, MCTs have been researched for their potential as a weight-loss tool. "It's been suggested that they may help increase the number of calories we burn and satiety, resulting in reductions in the amount of food we eat," Sollid says. But here's the thing: these studies have shown mixed results, and haven't been replicated in diverse populations, he says, so it's tough to say whether or not this is truly a safe and effective application for MCT oil. While burning more calories or obliterating cravings might sound promising to a person trying to lose weight, keep in mind that we need calories just to stay alive. Not to mention, your body's hunger and satiety cues are super important, because they're your body's way of signaling that you need fuel.
So, considering how little we know about MCT products or supplements, and how icky straight-up MCTs can make you feel, you might be better off opting for a different kind of oil. "Common cooking oils like olive, canola, and soybean oils have superior nutritional attributes that are known to benefit heart health," Sollid says. And they tend to be tastier than this ultra-processed stuff, too.