Waist-to-hip ratio

Method

Waist girth divided by hip girth from tape anthropometry at the landmarks stated by the source protocol - WHO specifies the waist at the midpoint between the lowest rib and the iliac crest and the hip at the widest gluteal circumference. The landmark convention is recorded on the edge; umbilical and narrowest-point waist conventions give different values.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

Its near-miss is CAT:outcome/waist-circumference, and the confusion is quantitatively consequential rather than merely definitional: this is a ratio whose numerator and denominator both shrink under caloric restriction, so it is systematically less sensitive to the same intervention. Both meta-analyses in this round found significant circumference effects alongside null ratio effects - mapping one to the other manufactures a null. Distinct also from waist-to-height ratio and from body mass index, and it carries no information about total adiposity, only about fat distribution.