Is Waist-to-Hip Ratio a Better Predictor of Health Risk Than BMI? A Look at the Latest Research
- Alastair Hunt
- Jun 11
- 6 min read
Updated: Jun 15
As science refines our understanding of health risks related to body fat, there's growing attention on where fat is stored in the body - not just how much we carry. Body mass index (BMI), the traditional tool for assessing obesity, has its limitations. A series of major new studies and analyses shed light on the waist-to-hip ratio (WHR) as a potentially more accurate and powerful predictor of premature death and cardiovascular events, including heart attacks.
As ever, please talk to your doctor or medical practitioner most familiar with your medical history before implementing any changes in diet, exercise or lifestyle, especially if you are under treatment. Links to all studies at bottom of page.
What is Waist-to-Hip Ratio, and Why Does It Matter?
Waist-to-hip ratio (WHR) is calculated by dividing the circumference of the waist by that of the hips. It gives a snapshot of fat distribution, particularly central (abdominal) fat, which is often more metabolically active and potentially harmful than fat stored elsewhere. While BMI simply relates weight to height, it doesn't reveal how fat is distributed—or differentiate between muscle and fat.
The World Health Organization defines abdominal obesity as a WHR of ≥0.90 for men and ≥0.85 for women. But these thresholds are under renewed scrutiny, as researchers investigate the relationship between WHR and major health outcomes.
'Central Fatness' and All-Cause Mortality
A comprehensive 2020 meta-analysis published in The BMJ examined 72 prospective cohort studies involving over 2.5 million participants. The authors found that increased WHR was associated with a significantly higher risk of dying from any cause—even after adjusting for BMI. Specifically, each 0.1 unit increase in WHR was linked to a 20% increase in the risk of death from any cause.
This relationship was stronger than that seen with BMI or even waist circumference alone. Importantly, the data revealed a steady, linear relationship: as WHR increased, so did mortality risk, without a clear "safe" range above which risk sharply rises.
The analysis also found that while larger waist circumference was associated with higher mortality, greater thigh and hip circumferences were linked with lower mortality. This supports the idea that not all fat is equal—fat stored in the hips and thighs may even be protective.
Genetic Evidence Strengthens the Case for WHR
In a 2023 UK Biobank study of nearly 388,000 adults, researchers compared the predictive power of BMI, fat mass index (FMI), and WHR using both observational data and genetic methods. The findings were striking: WHR had the strongest and most consistent association with all-cause mortality, outperforming both BMI and FMI.
For every standard deviation increase in WHR, the risk of death rose by 41% in observational data and 51% in genetic (Mendelian randomisation) analysis. Notably, WHR remained a strong predictor regardless of the person’s BMI. In other words, even individuals with a "normal" BMI but a high WHR were at elevated risk.
The association was particularly pronounced in men, where a higher WHR was linked with almost 90% greater odds of early death, compared to about 20% in women. This could reflect sex differences in fat distribution—men typically accumulate more visceral fat, while women have more subcutaneous fat.
WHR and Heart Attack Risk
The most recent addition to this growing body of evidence is a December 2024 meta-analysis focusing specifically on myocardial infarction (MI), or heart attack. Reviewing 22 studies involving over 709,000 participants, the analysis found that a higher WHR nearly doubled the risk of MI (98% increase).
Again, women appeared particularly affected: WHR was more strongly associated with heart attack risk in women than in men. This suggests WHR could be a powerful tool for identifying cardiovascular risk in populations traditionally underdiagnosed, such as women.
The study also found geographic variation in risk. The association between WHR and MI was strongest in Asian populations, followed by Europe and the Americas. Subgroup analyses suggested that higher WHR thresholds (≥0.93) carried even greater risk, hinting at a possible dose-response relationship.
Why WHR May Be Better Than BMI
Together, these studies highlight a critical point: where fat is stored may matter more than how much fat is present. Central fat is more metabolically active and linked to insulin resistance, chronic inflammation, and hormonal imbalances - all key drivers of cardiovascular disease and premature death.
In contrast, BMI can obscure risk in individuals with normal weight but high central fat ("normal weight obesity"), and it may overestimate risk in muscular individuals with high BMI but low body fat.
The genetic study adds weight to this argument by showing that WHR is not only a strong predictor but also likely plays a causal role in early mortality. The evidence supports WHR as a more useful tool for identifying high-risk individuals, particularly among those with misleading BMI scores.
How to Measure Your WHR
WHR is a simple, inexpensive measure requiring only a tape measure. It's accessible for both clinicians and individuals and may provide critical insight into health risks that BMI alone cannot.
To measure the WHR:
Waist: Measure at the narrowest part of your torso, usually just above the belly button. If unclear, use the midpoint between the bottom of the ribcage and the top of the hip bone.
Hip: Measure at the widest part of the buttocks, not at the hip bones.
Stand relaxed, feet together, and keep the tape snug and level.
For adults, a healthy WHR is:
For women, below 0.85
For men, below 0.90
However, as recent research suggests, even modest increases above these levels may be associated with rising health risks.
Final Thoughts
The evidence from these three major analyses is clear: waist-to-hip ratio offers a more precise, reliable view of health risks than BMI alone. Whether for predicting death from any cause or the likelihood of a heart attack, WHR has emerged as a critical marker - especially when considering its consistency across populations, sexes, and measurement methods. Another measurement that can be taken at home is the waist-to-height ratio. Learn more here.
While BMI will likely remain a useful screening tool, it may be time for waist-to-hip ratio to take a front seat in both clinical assessments and public health messaging. If you’re monitoring your health, it could be wise to grab a tape measure and keep an eye on your waist-to-hip ratio.
Improving health is about finding motivation, prioritising self-care and taking action. If you want to take effective and targeted steps that fit into your unique lifestyle, The Whole Health If your interest is weight loss, healthspan and longevity, to beat chronic illness or to enhance your mental health and wellbeing, our consultations and programs deliver results that are customised to your needs.
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Stay Healthy,
Alastair
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Related Studies and Resources
Khan I, Chong M, Le A, et al. Surrogate Adiposity Markers and Mortality. JAMA Netw Open. 2023;6(9):e2334836. doi:10.1001/jamanetworkopen.2023.34836
Lind L, Ahmad S, Elmståhl S, Fall T. The metabolic profile of waist to hip ratio-A multi-cohort study. PLoS One. 2023 Feb 27;18(2):e0282433. doi: 10.1371/journal.pone.0282433. PMID: 36848351; PMCID: PMC9970070.
Lind L, Ahmad S, Elmståhl S, Fall T. The metabolic profile of waist to hip ratio-A multi-cohort study. PLoS One. 2023 Feb 27;18(2):e0282433. doi: 10.1371/journal.pone.0282433. PMID: 36848351; PMCID: PMC9970070.
Liu Z, Yang H, Chen S, Cai J, Huang Z. The association between body mass index, waist circumference, waist-hip ratio and cognitive disorder in older adults. J Public Health (Oxf). 2019 Jun 1;41(2):305-312. doi: 10.1093/pubmed/fdy121. PMID: 30020483.
Jayedi A, Soltani S, Zargar MS, Khan TA, Shab-Bidar S. Central fatness and risk of all cause mortality: systematic review and dose-response meta-analysis of 72 prospective cohort studies. BMJ. 2020 Sep 23;370:m3324. doi: 10.1136/bmj.m3324. PMID: 32967840; PMCID: PMC7509947.
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