July 29, 2011
Dear Mayo Clinic:
What is it about belly fat that makes it more dangerous than fat in other places? I am considered to be at a healthy weight. But I do have somewhat of a belly, which concerns my physician. Isn't it just a normal part of getting older?
Belly fat is more dangerous than other types of fat, because it's associated with an increased risk of developing a range of serious health problems. Although belly fat can be more of a problem as we get older, it doesn't have to be part of the aging process. Regular exercise and a healthy diet can help you shed belly fat and keep you healthier as you age.
Belly fat is not the fat that lies just under the skin (subcutaneous fat). Instead, it's the fat that actually lies inside your abdomen and surrounds internal organs, such as your kidney and spleen. This is called visceral fat.
Subcutaneous fat and visceral fat are biochemically and functionally different. Visceral fat is more dangerous because it is more likely to produce substances that can damage your heart and blood vessels, and possibly interfere with your body's ability to use insulin. A large amount of belly fat can increase your risk for a number of diseases and medical conditions, including heart disease, high blood pressure, stroke, some types of cancer, type 2 diabetes, metabolic syndrome and sleep apnea.
Even though the belly fat that's dangerous is located within your abdomen, there is a strong correlation between your waist size and visceral fat. For most men, the health risk factors associated with visceral fat increase with a waist size greater than 40 inches. For women, a waist measurement of 35 inches or more typically indicates an unhealthy concentration of belly fat.
A formula called the body mass index (BMI) that compares your weight to your height may also be used to help assess body fat. The drawback to that method, though, is that your total weight includes muscle and fat. BMI measures both, without distinguishing between the two. You could be very muscular and have a high BMI. But the more muscle you have, the lower your overall cardiovascular risk. So a high BMI alone doesn't automatically mean your health risks are increased. To be meaningful when assessing body fat, BMI should be used along with a comparison of your waist and hip circumference (waist-to-hip ratio), as well as your overall waist size.
Aging may play a role in development of belly fat. Muscle mass gradually diminishes with age, and fat accounts for a greater percentage of your weight. Having less muscle mass decreases the rate at which your body uses calories, making it more challenging to maintain a healthy weight or lose excess pounds. But belly fat isn't inevitable.
The same techniques that work for other kinds of fat can help you get rid of excess belly fat. Eat a healthy diet, decrease your portion sizes and exercise every day. Sit-ups and other exercises targeted at your abdomen help tone your abdominal muscles, but they won't get rid of belly fat. If you have questions or concerns about the specific diet and exercises that are right for you, talk to your doctor.
— Virend Somers, M.D., Ph.D., Cardiovascular Diseases, Mayo Clinic, Rochester, Minn.