Waist-hip ratio

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The waist-hip ratio in women is often considered a key feature in physical attractiveness. Measured directly from this image, the frontal WHR of the model in this image is approximately 0.69.

Men generally have much less pronounced hips, relative to waist size.

Waist-hip ratio or Waist-to-hip ratio (WHR) is the ratio of the circumference of the waist to that of the hips. It is calculated by measuring the waist circumference (located just above the upper hip bone) and dividing by the hip circumference at its widest part (waist/hip). The concept and significance of WHR was first theorized by evolutionary psychologist Dr. Devendra Singh at the University of Texas at Austin in 1993. ^[1][2]

[edit] Use of WHR

[edit] Health

Studies show that 80 percent of women over the age of 18 have a WHR of at least 0.9^{[citation needed]}. This is a 40 percent increase since 2002, and it keeps increasing. A WHR of 0.7 for women and 0.9 for men have been shown to correlate strongly with general health and fertility. Women within the 0.7 range have optimal levels of estrogen and are less susceptible to major diseases such as diabetes, cardiovascular disorders and ovarian cancers.^[3] Men with WHRs around 0.9, similarly, have been shown to be more healthy and fertile with less prostate cancer and testicular cancer.^[4]

WHR has been found to be a more efficient predictor of mortality in older people than waist circumference or body mass index (BMI)^[5] If obesity is redefined using WHR instead of BMI, the proportion of people categorized as at risk of heart attack worldwide increases threefold.^[6] The body fat percentage is considered to be an even more accurate measure of relative weight. Of these three measurements, only the waist-hip ratio takes account of the differences in body structure. Hence, it is possible for two women to have vastly different body mass indices but the same waist-hip ratio, or to have the same body mass index but vastly different waist-hip ratios.

The ideal ratio for women is about 0.7.^[7]

Other studies have found that waist circumference, not WHR, to be a good indicator of cardiovascular risk factors,^[8] body fat distribution,^[9] and hypertension in type 2 diabetes.^[10]

[edit] Attractiveness

Scientists have discovered that the waist-hip ratio (WHR) is a significant factor in judging female attractiveness. Women with a 0.7 WHR (waist circumference that is 70% of the hip circumference) are usually rated as more attractive by men from European cultures^[11]. Such diverse beauty icons as Audrey Hepburn, Marilyn Monroe, Sophia Loren and even the Venus de Milo all have or had ratios close to 0.7, even though they all have different weights and heights. In other cultures, preferences appear to vary according to some studies,^[12] ranging from 0.6 in China,^[13] to 0.8 or 0.9 in parts of South America and Africa,^[14][15][16] and divergent preferences based on ethnicity, rather than nationality, have also been noted.^{[17] [18]}

Note: In the studies referenced above, only frontal WHR preferences differed significantly among racial and cultural groups. When actual (circumferential) measurements were made, the preferred WHR tended toward the expected value of 0.7 universally. The apparent differences are most likely due to the different body fat storage patterns in different population groups. For example, women of African descent tend to store their fat in their buttocks more than women of other groups. Therefore, their WHR as viewed from the front may appear to be much greater than when viewed from the side. The inverse may be true of women of East Asian ancestry. Therefore, African men appear to value a woman's small WHR in profile and Asian men may place more value on an exaggerated frontal WHR compared to European men.

It appears that men are more influenced by female waist-size than hip-size :

"Hip size indicates pelvic size and the amount of additional fat storage that can be used as a source of energy. Waist size conveys information such as current reproductive status or health status ... in westernized societies with no risk of seasonal lack of food, the waist, conveying information about fecundity and health status, will be more important than hip size for assessing a female's attractiveness."

—Journal of Biological Psychology, ^[19]

Another reason that men may favour a lower waist-hip ratio is that in stressful situations, women's hormones may decrease their WHR; the same hormones that act to make a woman physically stronger also make her WHR lower. ^[20]

[edit] Intelligence

While the study is still being reviewed, there is a moderate correlation between WHR and intelligence of offspring. Using data from the U.S. National Center for Health Statistics, William Lassek at the University of Pittsburgh in Pennsylvania and Steven Gaulin of the University of California, Santa Barbara, found a child's performance in cognition tests was linked to their mother's waist-hip ratio, a proxy for how much fat she stores on her hips.^[21]

Children whose mothers had wide hips and a low waist-hip ratio scored highest, leading Lassek and Gaulin to suggest that fetuses benefit from hip fat that contains polyunsaturated fatty acids critical for the development of the fetus's brain.^[21]

[edit] Artificial alteration

Many methods have been used to artificially alter a person's apparent WHR. These include corsets used to reduce the waist size and hip and buttock padding used by some transgendered people to increase the apparent size of the hips and buttocks.

[edit] See also

• Body fat percentage
• Body Mass Index
• Sagittal Abdominal Diameter (SAD)
• Central obesity
• Physical attractiveness
• Sexual attraction

[edit] References

[edit] External links

• Waist-hip ratio should replace body mass index as indicator of mortality risk in older people EurekAlert August 8, 2006
• Waist-to-hip ratio