What it is
Waist circumference divided by height. Most people track weight or BMI. Where fat sits on the body matters too, and this ratio is a simple way to check central fat that a scale alone misses.
How it is modeled (not scored)
Technical notes
The curve is Jayedi 2020 BMJ: dose-response meta-analysis, 72 cohorts, 2,528,297 people. Per 0.1-unit increase in waist-to-height ratio, all-cause mortality HR 1.24 (1.12–1.36), a nearly J-shaped association that persisted after adjusting for BMI. Main source: Jayedi. Supporting: Abdi Dezfouli 2023 (20 studies, per-1-SD HR 1.16 (1.07–1.25) / highest-vs-lowest HR 1.23 (1.04–1.41), corroborates magnitude, does not reproduce Jayedi's J-shape or 0.1-unit curve) / Carmienke 2013 (an earlier, pre-Jayedi synthesis that characterized waist-to-height ratio as monotonically positive rather than J-shaped, no single pooled HR stated) / Ashwell & Gibson 2014 (the 0.5 screening threshold's own honesty point: BMI alone would misclassify roughly 10% of the whole UK population, and over 25% of UK adults who are "normal weight" by BMI, as not needing to take care).
How to improve it
- Combine aerobic activity with strength training
- Measure waist and height together — weight alone can miss this