Burn the Fat, Feed the Muscle

By: David Bradley

Where fat comes from determines whether the body can metabolize it effectively. Researchers at Washington University School of Medicine in St. Louis have found that the "old" fat stored in the body's peripheral tissues that is, around the stomach, thighs or butt cannot be "burned" efficiently unless "new" fat is obtained from the diet or synthesized in the liver. In once sense this is good news for those hoping to "lose weight" but without sacrificing some of the fatty foods we all enjoy.

The researchers found that an important fat-making enzyme found in the liver, called Fatty Acid Synthase KnockOut in Liver (FASKOL), is essential for making new fatty acids, which are needed to keep your sugar, fat, and cholesterol levels healthy.

The effect of added dietary fat is also seen in lab mice lacking the FASKOL enzyme who are treated with a drug to activate a protein called PPAR-alpha. The researchers found that liver fat fell back to normal in the mice in just ten days if they were given this drug.

PPAR-alpha is found in all mammals, including humans, and is key to our metabolism allowing us to extract energy from carbohydrates and fats in our diet. "Scientists have argued that PPAR-alpha is activated by fats," explains team leader Clay Semenkovich, "But we've never known which fats or where they come from. This study suggests that new fat is a 'key' that unlocks the 'door' for PPAR-alpha in the liver."


The liver is very important for processing nutrients consumed in the diet and sending them on to the rest of the body. Abnormal processing of glucose or lipids in the liver contributes to problems of type 2 diabetes and atherosclerosis, and fatty liver disease often is seen in people who are obese or suffer from insulin resistance. The liver is also thought to play a key role in controlling the risk of heart disease.

The research team is now trying to identify which fats given in small amounts could activate the PPAR-alpha. They also are studying liver cells and fat cells to see how the liver can tell the difference between old fat and new fat.

Semenkovich believes the findings could one day lead to a new way to treat obesity, type 2 diabetes and metabolic disorders. For now, he says that dieters who want to lose fat stored in peripheral tissues may find it useful to take in small amounts of dietary fats, such as fish oils, that might more effectively activate PPAR-alpha and fat burning pathways through the liver.

This research is only in the early stages and new treatments are yet to be derived from it. However, it's never too late to take control of your own metabolism and help reduce your risk of diabetes and other health problems associated with being over weight by looking closely at your diet and the amount of exercise you do.