Waist | |
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The human waist
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Identifiers | |
FMA | 228775 |
Anatomical terminology
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The waist is the part of the abdomen between the rib cage and hips. On people with slim bodies, the waist is the narrowest part of the torso.
The waistline refers to the horizontal line where the waist is narrowest, or to the general appearance of the waist.
Because of this and because the waist is often synonymous with the stomach, one can become confused as to the exact location of the waist. Another confusing factor is that the waistline differs on different people. To locate the natural waistline, one need simply stand upright and then tilt over to the side keeping the legs and hips straight. Where the torso creases is the natural waistline.
Strictly, the waist circumference is measured at a level midway between the lowest rib and the iliac crest. The waist-hip ratio equals the waist circumference divided by the hip circumference. Practically, however, the waist is usually measured at the smallest circumference of the natural waist, usually just above the belly button for women and just below the belly button for men. In case the waist is convex rather than concave, such as is the case in pregnancy and obesity, the waist may be measured at a vertical level 1 inch above the navel.
The size of a person's waist or waist circumference, indicates abdominal obesity. Excess abdominal fat is a risk factor for developing heart disease and other obesity related diseases. The National Heart, Lung, and Blood Institute (NHLBI) classifies the risk of obesity-related diseases as high if men have a waist circumference greater than 102 cm (40 in) and women have a waist circumference greater than 88 cm (35 in).
A study published in the European Heart Journal April 2007 showed that waist circumference and waist-hip ratio were predictors of cardiovascular events.
Waist–hip ratio 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.
Waist–hip ratios of 0.7 for women and 0.9 for men have been shown to correlate strongly with general health and fertility. Colloquially this shape is compared to the hourglass shape.