Specific Type of Fat Could Increase Weight Loss by Modifying Metabolism

Eating a high fat diet is usually associated with weight gain. Now, though, scientists have announced that a certain type of fat may actually increase metabolism. The findings reveal a little bit more about how what you eat drastically impacts your body.

Scientists have noted in the past that the skeletal muscles of obese people contain a certain type of enzyme that breaks down saturated fats. In order to investigate this enzyme a bit further, the researchers genetically modified mice so that their muscles would constantly produce this enzyme. This allowed them to see what effect this enzyme had on the health of the rodents.

The enzyme itself is called SCD1. It has the ability to convert saturated fat into monosaturated fat, which is easier to metabolize. The liver will produce this enzyme only depending on the fat content of the food that's consumed. In fact, the researchers found that the mice that produced this enzyme seemed to have a faster metabolism.

"What we found in those animals is that they had a hypermetabolic rate compared to the wild mice, increased energy consumption and greatly increased these animals' exercise capacity," said Chad Paton, one of the researchers, in a news release.

After examining the skeletal muscles of the genetically modified mice compared to that of the wild mice, the researchers discovered higher levels of polyunsaturated fats. More specifically, they found linoleic acid, which is received only through diet. These higher levels of linoleic acid could only mean one thing--the modified mice were eating more food even though they actually weighed less. In fact, the modified mice's ability to exercise actually increased.

"They were increasing their energy consumption, and they greatly increased exercise capacity," said Paton. "For example, on the exercise wheels, normal mice fatigue after 7 to 10 minutes. These genetically modified animals wouldn't fatigue for about 70 minutes. So they were running a lot longer. Sedentary mice looked more like exercise-trained mice. This really made us look in a lot more detail what was happening in the skeletal muscle."

So what was happening exactly? More of the SCD1 enzyme and a great appetite meant more linoleic acid in the tissues. The linoleic acid switched on part of the muscle cell's DNA that encouraged the cells to make more mitochondria and to turn on a protein that encouraged the cell to burn off excess energy from the extra food as heat.

The findings could lead to a better understanding of how to modify human diet to achieve the same results. While genetically modifying humans isn't an option, it might be possible in the future to activate the same part of the DNA in human in skeletal muscles that burn off excess energy as heat instead of storing it.

The findings are published in the Journal of Lipid Research.