Subcutaneous fat is present directly under the skin, and Dr. Greuner says it's much easier to burn than the other two types. "It is simple to rid yourself of, as it burns quickly but serves two important purposes: to be a cushion for the rest of your body and to supply the skin with oxygen through its blood vessels," he says. "All fats can be prevented through diet and exercise, but visceral and subcutaneous are the most crucial to shed, as they can be the main cause of disease."
As men age, they're more likely to develop big bellies. After age 40, the natural reduction in testosterone means excess calories are often stored as visceral fat. Aging also makes you naturally lose muscle mass. Muscle keeps your metabolism burning at a solid rate. When you lose this muscle -- about 1 pound per year after age 30 -- your metabolism declines, and it becomes easier to gain fat, which often goes straight to the belly in men.
The stress hormone cortisol can really screw with your belly. The problem with cortisol is two-fold: First, the chemical makeup of cortisol causes the body to store visceral fat. Visceral fat is stored between your main organs and in the midsection and is the most dangerous type of fat. Experts state that visceral fat increases the risk of diabetes and heart disease.