Study Finds Losing Belly Fat Helps Improve Blood Vessel Function

Posted on March 23, 2012

A new study from Johns Hopkins researchers has found that losing belly fat, whether from a low-carb or a low-fat diet, helps improve blood vessel function. The results of the study were presented at an American Heart Association scientific meeting in San Diego on March 13.

In the six-month weight-loss study, Hopkins researchers found that the more belly fat the participants lost, the better their arteries were able to expand when needed, allowing more blood to flow more freely. The researchers also found that participants in the study who were on a low-carb diet lost about ten pounds more, on average, than those who were on a low-fat diet.

Kerry J. Stewart, Ed.D., a professor of medicine at the Johns Hopkins University School of Medicine and lead author of the study, says, "After six months, those who were on the low-carb diet lost an average of 28.9 pounds versus 18.7 pounds among those on the low-fat diet."

Stewart and his colleagues studied 60 men and women who weighed an average of 215 pounds at the start of the program. Half of the participants went on a low-carb diet while the others followed a low-fat diet. All took part in moderate exercise and their diets provided a similar amount of calories each day.

The researchers used a blood flow test by constricting circulation in the upper arm for five minutes with a blood pressure cuff to evaluate the health of the participants' blood vessels before and after the weight loss program. With this type of test, when the cuff is released, a healthier artery will expand more, allowing more blood to flow through the artery. The researchers measured how much blood reached the fingertips before, during, and after the constriction of the artery. Stewart says this test can give an indication of the overall health of the vascular system throughout the body. The researchers found that the more belly fat a person had lost, the greater the blood flow to the finger.

Stewart says, "Our study demonstrated that the amount of improvement in the vessels was directly linked to how much central, or belly fat, the individuals lost, regardless of which diet they were on. This is important since there have been concerns that a low-carb diet, which means eating more fat, may have a harmful effect on cardiovascular health. These results showed no harmful effects from the low-carb diet."