Waist-to-Hip Ratio: NHANES Microdata Derivation
FitnessNorms derived WHR from the CDC public body-measures and demographics files because NCHS does not publish this sex-by-age ratio table. The displayed values are transparent internal calculations, not official CDC estimates.
- Cohort: adults aged 20 and older with positive
BMXWAIST,BMXHIP, andWTMEC2YR; known pregnancies inRIDEXPRGare excluded. Final n=5,657; the smallest sex-by-age cell contains 134 people. - Calculation: WHR equals
BMXWAISTdivided byBMXHIP. Both inputs are centimetres. - Quantiles: P5, P25, P50, P75, and P95 use linear interpolation on midpoint cumulative-weight positions within each sex and 5-year age group.
- Survey design: MEC weights are applied to point estimates. Strata, clusters, and survey-design standard errors are not calculated.
Why the earlier pool was retired
The former page pooled 2017-March 2020 and 2021-2023. Review corrected its common-divisor weighting to observation-period fractions of 3.2/5.2 and 2/5.2. The all-quantile sensitivity check finds three differences over 0.02, all in female ages 20-24, with a maximum of 0.022. The latest release remains primary and the period-adjusted pool is sensitivity evidence only.
Public age is top-coded at 80. The 80+ trend coordinate at age 85 is a display anchor, not a mean observed age. NHANES measures waist at the iliac crest and hip at the maximum buttocks circumference. The WHO report uses a different waist landmark, so its cut-offs are not directly interchangeable with these percentiles. See the reference page for the remaining limitations.