Until recently, fats have gotten a bad rap, blamed for everything from weight gain to heart disease. At last, some forms of fat are being vindicated. Not all fats behave the same way. Most fats are made up of a glycerol backbone and fatty acids that have very long, carbon chains. To be absorbed by the intestines, these lengthy chains have to be broken down by enzymes in the small intestine into smaller, more manageable pieces.
However, medium-chain triglycerides are different. Medium chain triglyceride, or MCT, are a type of fat where the fatty acid branches are short enough that they don’t have to be chopped into fragments by intestinal enzymes to be absorbed. Instead, they enter the bloodstream and move directly to the liver where they can be oxidized and used for energy. In this way, they function more like carbohydrates than fats and are less likely to be stored as fat than long-chain triglycerides. Some research suggests medium chain triglycerides also promote weight loss and enhance exercise endurance.
Medium-Chain Triglycerides: Do They Help with Weight Loss?
There’s some evidence that medium chain triglycerides increase thermogenesis more than long-chain triglycerides do and are less likely to be stored as fat. They’re used directly as energy rather than being stored on hips, thighs, and tummies. Even more exciting, some research implies that getting more medium-chain triglycerides in the diet helps the body burn long-chain fatty acids more efficiently.
Medium-chain triglycerides, like all fats, give foods texture and increase satiety. One way fats increase satiety is by slowing down gastric emptying, the rate at which foods leaves the stomach. When food stays in your stomach longer, you feel fuller faster and are less likely to overeat. Interestingly, MCT’s are slightly lower in calories relative to long-chain fats, 8.3 calories per gram versus 9 calories per gram. In addition, some studies show that MCT’s increase thermogenesis and are less likely to be stored as fat relative to long-chain triglycerides.
Can Medium-Chain Triglycerides Boost Endurance in Athletes?
Because medium-chain triglycerides can be used directly as fuel by the liver, they may reduce glycogen breakdown during endurance exercise. By preserving muscle glycogen stores, they may increase exercise endurance. Bodybuilders are intrigued by the possibility that consuming medium-train triglycerides spares muscle breakdown by serving as a readily available source of fuel. Some athletes and bodybuilders on low-carb diets use medium-chain triglycerides as an alternative fuel source to carbs
But the news isn’t all so optimistic. Studies looking at the effects of medium-chain triglycerides on endurance and athletic performance have been mixed. Moderate amounts of MCT’s don’t seem to have a strong glycogen-sparing effect, although research shows higher doses may. The problem is higher doses can cause stomach upset.
There’s also the issue of heart health. Whether or not medium-chain triglycerides are heart unhealthy remains to be seen, but some proponents point out that cultures that eat large amounts of MCT’s, in the form of coconut oil, enjoy greater longevity. Plus, research shows medium-chain triglycerides have an anti-coagulant effect, helping to prevent blood clots that can lead to a heart attack or stroke. Plus, they have a modest glucose-lowering effect.
What Are the Best Sources of Medium-Chain Triglycerides?
The best sources of medium-chain triglycerides are coconut oil and palm oil. Coconut oil is growing in popularity because it has a medium-chain triglyceride content of about 66%. Some people take a MCT supplement, but it makes more sense to get medium-chain triglycerides by using coconut oil as a substitute for butter or other cooking oils.
Medium-Chain Triglycerides: Hope or Hype?
Whether or not medium-chain triglycerides boost endurance or enhance weight loss is still unclear. There’s more evidence supporting the benefits of MCT’s for fat loss than exercise endurance. According to some studies, medium-chain triglycerides are more satiating than long-chain ones. Add to that the fact that they boost thermogenesis and you can see how consuming MCT’s in place of long-chain fats favor fat loss.
Indeed there is some evidence that medium-chain triglycerides boost fat loss. In one study published in the American Journal of Clinical Nutrition, men and women who consumed MCT oil versus an equivalent amount of olive oil as part of a weight loss program, lost more weight over a 16 week period. Another study found obese men who consumed coconut oil rich in medium-chain triglycerides, experienced an increase in thermogenesis and reduced fat storage.
Although MCT-rich sources like coconut oil may be beneficial for fat loss, it’s too early to recommend eating large quantities of medium-chain triglycerides. If you do add coconut oil or other medium-chain triglycerides to your diet reduce the amount of fat you would otherwise eat to lower your total calorie intake. Talk to your doctor first if you have elevated lipid levels or are at high risk for heart disease.
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