Joan Endyke: Lower your carb intake to burn belly fat

Joan Endyke

Q: I read in a wellness magazine about the wonders of MCT oil, especially to combat belly fat. Do you have any information on this product?

Debbie in Milton, Mass.

A: Coconut and palm kernel oil are sources of MCT oil. Medium-chain triglycerides are fats that are absorbed and processed differently in the body than other fats and oils. Some studies suggest MCT is beneficial for weight loss, but the jury is still out.

Fats and oils are triglycerides made of a glycerol backbone with three fatty acids attached. Most vegetable and animal oils have fatty acids with long carbon chains, 12 or more, and are called long-chain triglycerides. Medium-chain triglycerides have 6 to 10 carbons.

Long-chain triglycerides are absorbed slowly and shuttled to fat cells to be stored or burned for energy. MCTs, which are more water-soluble, do not need bile acid for absorption. They are routed quickly to the liver and can be burned immediately for energy, similar to carbohydrates, but they do not stimulate insulin production, which promotes fat storage. This process requires more work and raises metabolism slightly, which could help with weight loss.

A few studies found that men lose an average of three pounds per month, women less than one pound, when MCT oil replaces some of the oils in the diet. But these studies were small and do not carry much significance unless replicated in larger groups.

Heart health is a concern with MCT oil. Coconut and palm kernel oil are highly saturated fats. Both contain 12 grams of saturated fat per tablespoon, compared to butter, which has seven grams. When you consider that heart disease is the leading killer of women, and that most adult women should limit total saturated fat to avoid raising bad (LDL) cholesterol, it’s important to use caution with MCT oils.

Proponents on websites claim coconut oil does not affect cholesterol. A study published in The American Journal of Clinical Nutrition in 2004, however, found a 12 percent increase in bad cholesterol and a 22 percent increase in triglycerides when subjects’ diets were changed form a neutral vegetable oil to 70 grams of MCT oil. Coconut oil contains lauric acid, a fatty acid that could benefit the heart in other ways, but more research is needed to determine if this outweighs the risks.

MCT oils do not contain any essential fatty acids and they are calorie-dense. Simply adding them to your diet without carefully cutting back calories from other foods will promote weight gain and belly fat.

A better way to burn belly fat is to lower carbohydrate intake to 40 to 45 percent of total daily calories and to choose the least processed, natural sources of carbohydrates. Both tactics will reduce insulin production.

Incorporate healthy fats to make up approximately 30 percent of calories and most importantly, keep total calories below energy expenditure. How? Why not try an Internet tool like Sponsored by Lance Armstrong, this free service will provide a calorie aim for weight loss. It’s easy to log your foods and at the end of the day a percent of carbohydrate, protein and fat is calculated for you. Keep all your numbers at goal – consistently – and you should see results.

Joan Endyke is a registered dietitian with a master’s degree in nutrition and food science, and also a certified personal trainer. She is the nutrition director at Fitness Unlimited. Readers may send questions about nutrition to Endyke at Fitness Unlimited, 364 Granite Ave., Milton, MA 02186 or by E-mail to The information in this column is not intended to diagnose individual conditions. Readers should see their doctors about specific problems.