Waist-hip ratio

Waist-hip ratio or Waist-to-hip ratio (WHR) is the ratio of the circumference of the waist to that of the hips. It measures the proportion by which fat is distributed around the torso. The concept and significance of WHR was first theorized by evolutionary psychologist Dr. Devendra Singh at the University of Texas at Austin in 1993.

Measuring
To calculate the ratio, use a non-stretchable tape. Make sure it is level around the body, parallel to the floor, and tighten it without depressing the skin. Measure the waist at its narrowest point width-wise, usually just above the belly button. Measure the hips around the widest part of the hip bones. Then divide the waist measurement by the hip measurement.

Health
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. Men with WHRs around 0.9, similarly, have been shown to be more healthy and fertile with less prostate cancer and testicular cancer.

WHR is a better measure of assessing a person’s risk of heart attack than Body mass index (BMI). If obesity is redefined using WHR instead of BMI, the proportion of people at risk of heart attack worldwide increases threefold.

Attractiveness
WHR is considered to be factor in a person's attractiveness. Devendra Singh originally argued that, on evolutionary grounds, men would find women with .70 WHRs more attractive. He argued this based on a study of the WHRs of Playboy models. However, later research found that his study was incorrect.

Women with a 0.7 WHR (waist circumference being 70% of the hip circumference) are sometimes rated as more attractive by men. Such diverse beauty icons as Marilyn Monroe, Sophia Loren, and even the Venus de Milo all have ratios around 0.7, even though they have significantly different weights.

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 cross-dressers to increase the apparent size of the hips and buttocks.