A new study suggests body shape may predict heart disease risk more accurately than body mass index (BMI). Specifically, measuring waist-to-height ratio (WHtR) — waist circumference divided by height — may identify people at higher risk for coronary artery calcium (CAC) buildup even when BMI appears normal.
Researchers published their findings in The Lancet Regional Health after following 2,721 adults in São Paulo, Brazil. Participants averaged about 48 years old, were roughly two-thirds female, and the group was racially diverse. All had no detectable CAC at baseline. Investigators recorded BMI, waist circumference, and WHtR, then rechecked CAC after five years.
About 15% of participants developed CAC over five years. While BMI, waist circumference, and WHtR all correlated with CAC in unadjusted analyses, only WHtR remained an independent predictor after accounting for traditional cardiovascular risk factors such as high blood pressure, elevated cholesterol, and diabetes. Those with a WHtR of 0.5 or greater had CAC buildup in about 18% of cases versus 10% for those with WHtR below 0.5. For each moderate increase in waist relative to height, the risk of developing coronary artery calcium rose by roughly 18%.
Study authors and outside experts note WHtR likely reflects visceral abdominal fat, which is metabolically active and linked to inflammation, atherosclerosis, diabetes, and other conditions. Because WHtR can reveal excess abdominal fat even in people whose BMI falls in the normal or overweight ranges (including BMI 25–29.9), it may flag individuals who would otherwise be missed by BMI-based screening.
Marcio Sommer Bittencourt, MD, PhD, noted the field is shifting from BMI to WHtR for cardiovascular outcomes related to metabolic and atherosclerotic disease. Thiago Bosco Mendes, MD, emphasized that WHtR identified higher risk for arterial sclerosis development after five years even after adjusting for classic cardiovascular risk factors. Yu-Ming Ni, MD, a cardiologist not involved in the study, agreed that waist-based measures are useful markers of metabolic dysfunction and heart risk.
Why WHtR may outperform BMI
– BMI estimates body fat from height and weight but does not capture fat distribution. Two people with identical BMI can have very different amounts of abdominal (visceral) fat.
– WHtR directly reflects abdominal fat relative to body size, which is more closely tied to metabolic dysfunction, inflammation, and atherosclerotic plaque formation.
– In the study, the association between larger WHtR and CAC was not fully explained by traditional metabolic measures, suggesting additional harmful effects of abdominal fat.
Clinical and public-health implications
WHtR is simple to measure and could become a routine screening tool to detect cardiovascular risk missed by BMI, especially in people who appear healthy by weight alone. That said, clinicians still recommend established prevention measures — healthy diet, regular exercise, reduced caloric intake when needed, and limiting ultra-processed foods — to lower abdominal size, WHtR, and overall risk.
How to measure your waist-to-height ratio at home
1. Use a tape measure long enough for your height.
2. Measure your height without shoes and record it in inches or centimeters.
3. Measure your waist around the bare abdomen at the level of the belly button, breathing out normally.
4. Divide your waist measurement by your height using the same units.
5. Example: waist 34 inches ÷ height 68 inches = 0.5.
6. Rule of thumb: keep your waist less than half your height; WHtR ≥ 0.5 suggests increased risk.
Bottom line
WHtR offers a quick, inexpensive way to gauge risk for coronary artery calcium and future heart disease beyond BMI or waist circumference alone. It may be particularly valuable for spotting risk in people whose BMI suggests they are healthy, highlighting the importance of abdominal fat as a target for prevention.
