A normal BMI isn't the full story. Your waist matters too.
People say: “BMI is the number most used to judge obesity” We read the study.
Cohort study. 260,959 people. median follow-up 20.0 years (IQR 12.7-23.5); waist and hips measured once at baseline.
People were watched for years. Nobody was told what to do. A clue, not proof.
Who: Adults from 15 NIH/NHLBI-type cohorts (ARIC, CARDIA, CHS, CRIC, DHS, ELSA-Brasil, FHS, JHS, MESA, REGARDS, Rancho Bernardo, Strong Heart, SOF, SWAN, WHI), predominantly US (ELSA-Brasil from Brazil), predominantly female (~84% in Table 1), mean age ~60-63 by group; no reported coronary heart disease at baseline, BMI >= 18.5. 260,861 with waist circumference, 220,370 with waist-to-hip ratio
- Big waist, BMI < 30+15–50%most of 9 outcomes
- Obese, normal waistnoneno clear risk rise
More to know, from our read of the paper:
- Observational: association, not causation; authors: 'cannot exclude residual confounding and cannot establish causality'
- No measures of physical activity, diet or genetic obesity risk in the analysis (authors' limitation)
- Waist and hips measured only once at baseline; cohorts began decades ago, so may under-represent today's obesity patterns (authors' limitation)
- '15-50% greater risk for most outcomes' is the abstract's pooled summary for normal weight OR overweight with clinically high waist circumference or waist-to-hip ratio. Not every outcome in every subgroup: e.g. men with normal weight and high WC were only significantly higher for CVD death and all-cause death (Supplemental Fig 5). Keep the 'most outcomes' wording
- Obesity + low WC 'not significantly different' is NOT 'same risk' (absence of evidence). It applied to only 9% of people with obesity. By waist-to-hip ratio it did not hold for women: women with obesity and low WHR still had significantly higher risk for all outcomes (Abstract; Results), though lower than those with high WHR
Your waist shows what BMI misses.
- Check your waist, not just BMIHigh here: over 88 cm (women), 102 cm (men).
This study pooled 15 long-running cohorts, mostly in the US, with about 261,000 adults (mostly women) without heart disease at the start, followed for a median of 20 years. With a normal or overweight BMI, a high waist size or waist-to-hip ratio was linked to 15-50% higher risk for most of 9 heart and death outcomes. People with obesity but a waist under the cutoff (only 9% of them) showed no clear extra risk for most outcomes versus normal weight; by waist-to-hip ratio, women with obesity still had higher risk. Observational: linked, not proven.
Dardari ZA, Yao Z, Zhang J, Bakoyannis G, Nan H, Staten LK, Jha KK, Tasdighi E, Jelwan Y, Burka S, Matsushita K, Lima JAC, Psaty BM, Fretts AM, Lemaitre RN, Cohen DL, Appel LJ, Khera A, Shah AM, Hall ME, Judd SE, Safford MM, Cole SA, Vasan RS, Benjamin EJ, Cawthon PM, Orwoll E, LaMonte MJ, Eaton CB, El Khoudary SR, Jackson EA, Janssen I, Lotufo PA, Bensenor IM, Bittencourt MS, Bhatt AS, Ricardo AC, Blaha MJ (2026). Risk Reclassification Beyond BMI by Waist Circumference and Waist-to-Hip Ratio Across 9 Cardiovascular Outcomes: Results From the Cross-Cohort Collaboration. Journal of the American College of Cardiology.
Design: Cohort study · pooled analysis of 15 prospective cohorts (Cross-Cohort Collaboration), multivariable Cox models with a shared frailty term; observational (linked, not proven)
DOI: 10.1016/j.jacc.2026.05.050
Goals:
We read the abstract and the full text of this paper and checked every number on this page against it (18 facts, checked on 2026-10-29). The study design is named above. Cohort and other observational studies are described as linked, not proven. Found an error? Email theis@onestudyaday.com.
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