Waist-to-Hip Ratio

Waist-to-hip ratio (WHR) is used as measurement for body composition to determine how much fat a person has around his or her abdomen (stomach area). This measurement is obtained by determining the circumference of both the waist and the hips in centimeters or inches and then dividing the value for the waist by the value for the hips. People who have a high WHR tend to have more of their body weight deposited around their abdomen. This is sometimes referred to as an anoid or apple-shaped body. People who have a low WHR tend to have more of their body weight deposited in the lower portion of their body. This is sometimes referred to as a gynoid or pear-shaped body. When males gain weight, it tends to be around their abdomen and thus are more likely to have a high WHR when they become overweight or obese. Some women will also gain weight around their abdomen, but women may also gain weight in the lower portion of the body (i.e., around their thighs and buttocks) and these women would have a low WHR. Other tests may also be used to determine how much fat a person deposits around his or her abdomen and these include skin fold measurements, bioelectrical impedance analysis (BIA), magnetic resonance imaging (MRI) scans, computed tomography (CT) scans, and dual energy X-ray absorptiometry (DEXA) scans.

Numerous studies have explored the use of the WHR for both clinical and research purposes. There appears to be an increased risk of developing certain diseases such as heart disease and Type 2 diabetes mellitus with an increased WHR. Likewise, having a low WHR is protective against the development of these diseases. WHR is good predictor for the development of these diseases. Body mass index (BMI) is another body composition measure. BMI is also a ratio; BMI is a person's weight per the amount of height (the height is squared). WHR is a better predictor than BMI for heart disease and Type 2 diabetes mellitus, but BMI is a very good predictor of many other diseases including kidney disease. A high WHR can also be associated with elevated levels of many of the proinflammatory proteins in the body including C-reactive protein, tumor necrosis factor-alpha, and the interleukins. Elevated levels of these inflammatory proteins are usually associated with increased risk of developing heart disease. Several cancers including breast, colon, and prostate are more likely to develop in people who have a high WHR.

There are several advantages and disadvantages for using WHR as a tool to measure how much fat is around the abdomen. One advantage of using WHR is that it is a simple measurement to acquire. Once a researcher has been properly trained, he or she can easily measure the WHR of many subjects. Additionally, this measurement is very useful for physicians. Physicians do not need to buy expensive equipment or to send their patients for expensive tests to acquire these measurements. Physicians can assess the risk that patients have for developing diseases such as heart disease and Type 2 diabetes mellitus with just a simple tape measure. The WHR measurements can be performed during an annual physical exam as a marker of general [Page 786]health status and be used to evaluate the change in a patient's body composition over time.

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