Waist-to-hip ratioWHR

Waist to hip ratio is waist circumference divided by hip circumference. It describes where you carry weight rather than how much of it there is, distinguishing an apple shaped distribution from a pear shaped one.

It matters because location carries more risk information than total weight. Fat around the abdomen, particularly the visceral fat inside it, is metabolically active and drains directly to the liver, and it tracks with insulin resistance and cardiovascular disease far more closely than fat on the hips and thighs.

The WHO expert consultation set the thresholds most widely used: 0.90 or above in men and 0.85 or above in women marks substantially increased risk of metabolic complications.

Measurement protocol matters more than people expect, and the same report specifies it: waist at the midpoint between the lowest rib and the top of the hip bone, hips at the widest point of the buttocks, tape parallel to the floor, measured at the end of a normal breath out. Sloppy technique moves the ratio more than a month of training does.

Its main rival is waist to height ratio, which needs only one measurement and a number you already know, and which a review of 78 studies found predicted cardiometabolic outcomes more often than BMI.

Neither is a diagnosis. They are cheap screening measures that tell you whether to look more closely, and they complement rather than replace blood pressure, glucose and lipids.

In practice, measure properly, track the trend, and use our waist to hip and waist to height calculators together with the scale rather than instead of it.

Sources

• World Health Organization. Waist circumference and waist-hip ratio: report of a WHO expert consultation (2008)
• Browning LM, Hsieh SD, Ashwell M. A systematic review of waist-to-height ratio as a screening tool for the prediction of cardiovascular disease and diabetes: 0.5 could be a suitable global boundary value. Nutr Res Rev 2010;23:247-269