Published: April 9, 2003

Most people know it's unhealthy to be overweight, but researchers now say it's important not only how much body fat you have, but where you have it.

According to CU-Boulder Kinesiology Professor Robert Mazzeo, studies show that the bigger the belly the more likely a person is to develop diabetes, heart disease and other health problems.

"Abdominal, or visceral, fat is fat that surrounds your internal organs," said Mazzeo. "The health concern with the accumulation of visceral fat is the development of diabetes, and you're also at a greater risk for heart disease, stroke and hypertension."

So far, researchers do not know the exact reason why visceral fat causes diabetes and other diseases. According to Mazzeo, a couple of theories suggest visceral fat interferes with insulin production in the pancreas. High levels of dangerous cholesterol and triglycerides may be secreted by the visceral fat and absorbed by the liver and other internal organs, eventually making their way into the bloodstream.

About 90 percent of all diabetics have type 2 diabetes, which impairs a person's ability to process glucose or blood sugars and is associated with obesity.

According to Mazzeo, people can reverse the effects of unhealthy visceral fat by exercising three to four times a week. He recommends aerobic exercise lasting 30 minutes to 45 minutes for each session.

"The best type of exercise is one that burns a lot of calories. An aerobic type of exercise, where you're recruiting large muscle groups for a prolonged period of time, is better at burning calories than short bouts of exercise or even resistance training."

To help in the battle of the bulge, Mazzeo recommends the following diet and exercise habits:

* avoid foods high in saturated fats and trans-fatty acids -- solid fats produced artificially by heating liquid vegetable oils. Some studies have shown that trans-fatty acids raise the LDL cholesterol levels, the so-called "bad" cholesterol, and lower HDL or "good" cholesterol.

* consume fish high in omega-3 fatty acids and olive oil because they appear to have a beneficial effect on reducing visceral fat.

* create a negative energy balance by burning more calories than you take in either by dieting, exercising or a combination of both.

For more information contact Robert Mazzeo at (303) 492-1509 or Dirk Martin in the CU-Boulder Office of News Services at (303) 492-3140.