There are two kinds of body fat—subcutaneous fat and visceral fat. Subcutaneous fat sits just below the skin; you can pinch it (think muffin top). Although visceral or abdominal fat, is found deep inside your gut, it's the reason your belly protrudes. Since it pads the body's organs, it can't be seen or touched. But here's the fat truth: visceral fat increases your risk for cardiovascular disease, type 2 diabetes, colorectal cancer, sleep apnea, and more. Plus, it raises the risk of breast cancer in women.

Abdominal fat accumulates when we consume more calories than we expend. And the aging process doesn't help the situation either since as we get older, we lose muscle, especially if we're not physically active. This loss of muscle mass means our body uses calories less efficiently, so it can become more challenging to maintain a healthy weight. For some people (especially men), fat cells in the arms and legs lose their ability to store fat, which causes excess fat to go the abdomen.

Visceral fat cells are also biologically active, which means they disrupt the normal balance and functioning of hormones, especially cytokines, which contributes to a greater risk of cardiovascular disease. To make matters worse, visceral fat releases fatty acids into the bloodstream where it can negatively impact the production of blood lipids in the liver. It's also connected to higher total cholesterol, higher LDL (bad cholesterol), lower HDL (good cholesterol) and insulin resistance, raising the risk for type 2 diabetes.

If that's not reason enough to trim your tummy, consider that abdominal fat seems to lower brain volume, which is associated with a higher risk of dementia. Researchers aren't sure why this is, but speculate it's related to inflammation. A large, population-based study found that the presence of central obesity in midlife almost triples the risk of dementia in later life, independent of diabetes, stroke, hypertension, and heart disease.

Although there are several ways to gauge how much abdominal fat you have, the easiest way is to measure your waist circumference just above your hip bones. The measuring tape should fit snugly, but not push into the skin. Make sure it is level all the way around. Relax, exhale, and measure. A waist size of 35 inches or higher for women or 40 for men is too high.

Fortunately reducing the amount of belly fat you have is within your control since it responds well to diet and exercise. Losing even 5 to 10 percent will help lower your risk for disease. Engage in moderate intensity exercise, including strength training. Watch portion sizes. Consume a diet that emphasizes complex carbohydrates and replaces saturated fats with polyunsaturated fats and watch your waistline shrink.

Allison Massey, MS, RD, LDN, CDE, reviewed this article.



Sources:


The Harvard Medical School Family Health Guide
"Abdominal Fat and What to Do About It," accessed 11 Aug 2013 http://www.health.harvard.edu/fhg/updates/Abdominal-fat-and-what-to-do-about-it.shtml

Medscape Medical News
"Central Obesity in Midlife an Independent Risk Factor for Dementia," Caroline Cassels
27 March 2008
http://www.medscape.com/viewarticle/572067

"Abdominal Obesity Linked to Lower Total Brain Volume in Healthy Middle-Aged Adults," Pam Harrison
26 May 2010
http://www.medscape.com/viewarticle/722471

National Heart Lung & Blood Institute
"Assessing Your Weight and Health Risk," accessed 11 Aug 2013
http://www.nhlbi.nih.gov/health/public/heart/obesity/lose_wt/risk.htm

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"Belly Fat In Men: Why Weight Loss Matters," 5 Feb 2011
http://www.mayoclinic.com/health/belly-fat/MC00054