WEDNESDAY, July 10 (HealthDay News) -- People with excessive belly fat have a greater risk of heart disease and cancer than those who have fat in other body areas, a new study finds.

Researchers used CT scans to assess fat in the abdomen, around the heart tissue and around the aortic artery in more than 3,000 Americans, average age 50. They were then followed for up to seven years.

During the follow-up, there were 90 cardiovascular events, 141 cancer cases and 71 deaths. Abdominal fat -- which typically indicates fat around internal organs -- was associated with an increased risk of heart disease and cancer, the investigators found.

The findings, published online July 10 in the Journal of the American College of Cardiology, might explain why people with a similar body mass index (BMI) but different body types have varied obesity-related health problems. BMI is a measure of body fat based on height and weight.

"Contrary to previously published studies comparing BMI and waist circumference, the presence of abdominal fat improved the ability to predict for cardiovascular disease, supporting the hypothesis that abdominal fat may partially underlie the association of body fat and heart disease and cancer," study senior author Dr. Caroline Fox, a senior investigator at the U.S. National Heart, Lung, and Blood Institute's Laboratory for Metabolic and Population Health, said in a journal news release.

"Given the worldwide obesity epidemic, identification of high-risk individuals is important, as it allows targeting of preventive and therapeutic measures," study author Dr. Kathryn Britton, an instructor of medicine at Brigham and Women's Hospital in Boston, said in the news release.

Although the study found an association between having more abdominal fat and the development of heart disease and cancer, it did not prove a cause-and-effect relationship.

More information

The U.S. National Institutes of Health outlines what you can do to reduce heart risks.