Why worry about your back?

Excess fat around your midsection is particularly dangerous to your heart.

For a long time, experts have warned that an enormous belly is more harmful to your heart than extra padding in your hips and thighs. According to the most recent statistics from the CDC, an increasing variety of Americans at the moment are sporting this unhealthy “apple-shaped” profile.

The average waist circumference for men is now 40.2 inches, up from 39 inches recorded within the previous survey, conducted in 1999-2000. Women's waist measurements also increased – from 36.3 to 38.6 inches on average. That means most Americans now have stomach sizes that put them at high risk (see “Gut Check: How to Measure Your Midsection”).

Gut Check: How to Measure Your Midsection To measure your waist accurately, exhale and wrap the measuring tape around your bare stomach just above the upper border of your hips, which you’ll easily feel on either side. Do not suck into your gut or pull the tape so tight as to squeeze the realm. To calculate your waist-to-hip ratio, first measure your hips by placing a tape measure across the widest a part of your hips. Place the tape measure level. Then, divide your waist size by your hip size.
Measurements that indicate high risk.
	waist (inches)	Waist to hip ratio
Women	35 or more	0.9 or higher
Men	40 or more	1.0 or higher

Location matters.

Visceral fat accumulates deep inside the abdominal cavity, filling the space between the organs. When these fat cells break down, they flood the portal vein (the vein that carries blood from the intestinal tract to the liver) with free fatty acids and other substances. The resulting condition, “lipotoxicity,” affects the nearby pancreas, inhibiting its ability to supply insulin, the hormone that transports glucose into the body's cells. Lipotoxicity also promotes insulin resistance, during which the body's muscle and liver cells don’t respond adequately to normal levels of insulin. As a result, blood sugar levels rise, increasing the chance of type 2 diabetes.

Also, when these misplaced fat cells die, the cells that act as cleanup crews release inflammatory substances called cytokines. “Those cytokines are one of the reasons people develop atherosclerosis, which is the main cause of heart disease,” says Dr. Hamdi.

In contrast, fat collected within the hips and thighs appears to be less harmful. People with this “pear-shaped” profile of fat distribution are less liable to diabetes and heart disease than individuals with a bigger belly.

Who is weak?

Your genes, ethnic background, and gender all affect how likely you’re to build up visceral fat. This problem is less common in people in Mediterranean countries, where heart disease can also be less common. But Native Americans, Pima Indians, Hispanics, and other people living in India and South Asia usually tend to have abdominal obesity (in addition to type 2 diabetes). Finally, white men and black women accumulate relatively more visceral fat than black men and white women.

Girth control

While there's no magic formula for losing belly fat, a low-carb food regimen might be helpful, especially if you may have type 2 diabetes, says Dr. Hamdi. You don't need to avoid all carbs—just steer clear of those that spike your blood sugar levels and encourage your body to store fat. These three sources are major culprits:

1. Sugar. Anything made with added sugar — cookies, cakes, pastries, ice cream, soft drinks, canned juices, and the like.

2. white flour. The mostly used examples (and worst offenders) are what Dr. Hamdi calls the “P's and B's”: pasta, pizza, bread, and bagels.

3. Starchy foods. White potatoes, rice and corn.

Intermittent fasting or timed eating may help improve your body's insulin response and reduce visceral fat. The basic idea is to limit your food intake to lower than usual. For example, you’ll be able to only eat between 8am and 2pm after which fast until the following morning, or abstain from eating for not less than 14 hours after your last meal of the day. . Do this three days per week after which eat as normal for the remaining 4 days, Dr. Hamdi recommends. And don't forget to get regular exercise (each aerobic and muscle-strengthening), which might enable you to burn extra calories and help preserve lean muscle.

Photo: © Martin/Getty Images