In contrast, excess fat at the hips or thighs is unrelated to disease risk in women who have BMIs of 25 or less. One theory is that the chemical by-products of fat metabolism are emptied into the vessels of the abdomen and are circulated to the liver, where they influence the production of blood lipids. Visceral fat has also been associated with insulin resistance. In that condition, the body does not respond adequately to insulin, the pancreatic hormone that enables glucose to enter the cells. The glucose level in the blood rises and with it, the risk of diabetes.
Ethnicity also plays a role in fat distribution.
Extensive studies have been done over the last three decades comparing African-American and Caucasian women. Although African-American women tend to have greater bone density and muscle mass than Caucasian women, they also have a higher rate of obesity and a greater tendency to develop visceral fat and therefore a higher risk of heart disease and diabetes. The rounded abdomen is associated not only with the male physique but also with men's health risks. Exercise and diet changes may help to correct the situation. Exercise Regular activity is now accepted as the key to weight loss and control.