Belly fat predicts heart disease risk better than BMI, study finds
A 20-year analysis finds waist measurements can expose major differences in heart risk among people with similar BMI scores
Edited By: Joseph Shavit/
American College of Cardiology Writer: Olivia Walther
Published Aug 13, 2026 11:07 AM PDT
Waist size and cardiovascular risk are closely linked, and measuring the midsection may identify dangers that BMI alone misses. (CREDIT:
- A normal BMI can still miss abdominal fat patterns linked to a higher risk of heart disease, stroke, heart failure and other cardiovascular problems.
- In nearly 260,000 people followed for about 20 years, waist size and waist-to-hip ratio helped separate higher-risk and lower-risk people within the same BMI categories.
- The findings support using simple waist measurements alongside BMI, although the observational study cannot prove that abdominal fat directly caused cardiovascular disease.
A person can fall within the “normal” body mass index range and still carry a pattern of abdominal fat linked to higher cardiovascular risk. A large long-term analysis suggests that waist measurements can expose risk that BMI alone may miss
The study, published in JACC and led by researchers working through the Cross Cohort Collaboration, examined nearly 260,000 people without a reported history of coronary heart disease. Participants were followed for an average of about 20 years
BMI remains one of the most familiar clinical measures for classifying normal weight, overweight and obesity. It is calculated by dividing weight in kilograms by height in meters squared. The World Health Organization endorses BMI as a clinical tool for diagnosing obesity, but the measure does not show where body fat is stored
That distinction matters because abdominal fat includes visceral fat, which surrounds internal organs, and subcutaneous fat beneath the skin. Visceral fat is more metabolically active and has been linked to processes associated with diabetes, hypertension, abnormal cholesterol levels, atherosclerotic plaque formation and other metabolic disorders
Normal BMI did not always mean lower risk
The researchers compared BMI with waist circumference and waist-to-hip ratio, two measures used to estimate central adiposity, or fat concentrated around the abdomen
Their final analysis included 259,351 people with waist circumference data and 218,984 with waist-to-hip ratio data. The team assessed nine cardiovascular and mortality outcomes, including heart attack, stroke, heart failure, atrial fibrillation, coronary heart disease, cardiovascular disease, cardiovascular deaths, coronary deaths and death from any cause
Among people classified as normal weight by BMI, 5% had a high waist circumference and 18% had a high waist-to-hip ratio. Among those classified as overweight, 39% had a high waist circumference and 40% had a high waist-to-hip ratio
The mismatch also appeared among people with obesity. Nine percent had a low waist circumference, while 45% had a low waist-to-hip ratio
“Indeed, it appears that WC and WHR reclassify risk defined by traditional BMI thresholds,” said Michael J. Blaha, MD, MPH, senior author of the study and director of clinical research at Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease. “We saw individuals with clinically determined normal weight who had elevated central adiposity and high WHR, associating them with higher risk across most outcomes.”
Waist measurements changed the risk picture
People with normal weight or overweight who also had clinically defined high waist circumference or waist-to-hip ratio were associated with a 15% to 50% greater risk for most of the nine outcomes
Within every BMI category, higher waist circumference and higher waist-to-hip ratio were also associated with higher adjusted incidence rates for each outcome
The researchers used clinical cutoffs that defined high waist circumference as greater than 88 centimeters for women and greater than 102 centimeters for men. A high waist-to-hip ratio was greater than 0.85 for women and greater than 0.90 for men
The pattern was especially striking in people whose BMI suggested normal weight. Higher waist circumference quartiles were significantly associated with greater risk for all nine outcomes. Higher waist-to-hip ratio quartiles were associated with greater risk for all outcomes except atrial fibrillation
At the other end of the BMI range, people with obesity and low waist circumference generally did not have significantly different risks from people with normal weight and low waist circumference. The exception was all-cause mortality, which was significantly lower
“Our findings emphasize the critical role of identifying elevated central adiposity, even in individuals with a normal BMI or with a BMI in the overweight range. Relying solely on BMI may result in misclassification of cardiovascular risk across a wide range of cardiovascular outcomes,” said Zeina A. Dardari, PhD, MS, lead author of the study. “We encourage clinicians to consider central adiposity distribution across the entire BMI spectrum when evaluating cardiovascular risk in primary prevention settings.”
Abdominal fat carried a substantial population burden
The analysis also estimated the proportion of events associated with high waist measurements within each BMI category
Among people with obesity, high waist circumference accounted for the largest estimated fractions. The population attributable fraction reached 48.9% for heart failure and 46.2% for atrial fibrillation. It was 35.4% for coronary heart disease and 36.3% for coronary heart disease mortality
Among people classified as overweight, high waist-to-hip ratio produced the largest estimates for heart failure and heart attack. The corresponding population attributable fractions were 23.7% and 22.2%
These estimates do not prove that abdominal fat directly caused those events. The research was observational, so it cannot establish causality
The study also lacked measurements of physical activity, diet and genetic obesity risk, all of which can influence cardiovascular disease. Researchers measured waist circumference and waist-to-hip ratio only once, limiting their ability to track how changes in abdominal fat over time might affect later risk
“It is time to abandon a sole focus on body mass index,” said Harlan M. Krumholz, MD, FACC, Editor-in-Chief of JACC and the Harold H. Hines, Jr Professor at the Yale School of Medicine
Practical implications of the research
The findings support using waist measurements alongside BMI when clinicians assess cardiovascular risk, especially when a patient’s BMI appears reassuring
A normal BMI did not consistently identify people with lower central fat levels, while obesity by BMI did not always correspond to the same level of risk when waist circumference was considered. That means two people in the same BMI category may have substantially different cardiovascular profiles
Waist circumference and waist-to-hip ratio are also relatively simple measurements. The study suggests they can add information that BMI cannot provide about fat distribution
For prevention, that added information could help clinicians identify people whose abdominal fat places them in a higher-risk group despite a normal or overweight BMI. It could also sharpen risk assessment across the obesity range
The authors argue that cardiovascular evaluation should account for where fat is stored, not only how much a person weighs relative to height
Dig deeper into abdominal fat, BMI limits and cardiovascular risk
These renewer obesity definitions can improve risk assessment beyond BMI alone
Adiposity-based obesity classification and cardiometabolic and kidney outcomes: a longitudinal UK Biobank analysisFollowing 489,311 UK Biobank participants, researchers found that combining body-fat percentage with waist circumference separated people into substantially different risks for cardiovascular events, type 2 diabetes and chronic kidney disease. Nearly one-third of people in the highest-risk adiposity group still had BMI values in the normal-to-overweight range. (eBioMedicine, 2026)
Definition and diagnostic criteria of clinical obesityThis international commission proposed moving beyond BMI alone by confirming excess body fat through direct measurement or measures such as waist circumference, waist-to-hip ratio or waist-to-height ratio. It also distinguishes clinical obesity from excess adiposity that has not yet produced organ dysfunction or physical limitations. (The Lancet Diabetes & Endocrinology, 2025)
Normal-weight obesity subtypes and 10-year risks of major vascular diseases in 0.3 million adultsA prospective analysis of more than 308,000 adults found that central obesity among people with normal BMI was associated with increased risks of major vascular events. Waist circumference was particularly informative for ischemic heart disease risk, reinforcing the importance of looking beyond body weight alone. (Clinical Nutrition, 2025)
Association of combined body mass index and central obesity with cardiovascular disease in middle-aged and older adults: a population-based prospective cohort studyThis prospective study examined BMI together with abdominal obesity and found that cardiovascular risk differed meaningfully when the two measures were considered together. The results support assessing both general body size and central fat accumulation when evaluating cardiovascular health. (BMC Cardiovascular Disorders, 2024)
Surrogate Adiposity Markers and MortalityUsing data from 387,672 UK Biobank participants along with genetic analyses, researchers compared BMI, fat mass index and waist-to-hip ratio. Waist-to-hip ratio showed the strongest and most consistent association with all-cause mortality, providing additional evidence that fat distribution can carry information BMI misses. (JAMA Network Open, 2023)
Research findings are available online in the Journal of the American College of Cardiology
The original story “Belly fat predicts heart disease risk better than BMI, study finds” is published in The Brighter Side of News
- Study finds BMI isn’t a reliable health tool after all
- Internal fat may be the leading cause of heart failure, study finds
- Hidden muscle fat significantly raises heart disease risk, study finds
Like these kind of feel good stories? Get The Brighter Side of News’ newsletter
abdominal fatAtrial FibrillationBelly FatBMICardiovascular Diseasecardiovascular riskCross Cohort CollaborationHealth NewsHeart AttackHeart DiseaseHeart FailureJohns Hopkins UniversityMedical Good NewsObesityResearchSciencestrokevisceral fatwaist circumferencewaist-to-hip ratio
Joseph ShavitScience News Writer, Editor and Publisher
Joseph ShavitWriter, Editor-At-Large and Publisher
Joseph Shavit, based in Los Angeles, is a seasoned science journalist, editor and co-founder of The Brighter Side of News, where he transforms complex discoveries into clear, engaging stories for general readers. With vast experience at major media companies like The Los Angeles Times, Times Mirror and Tribune Publishing, he writes with both authority and curiosity. His writing focuses on space science, planetary science, quantum mechanics, geology. Known for linking breakthroughs to real-world markets, he highlights how research transitions into products and industries that shape daily life.
Latest Stories
Good NewsRutendo Shadaya wrote a fantasy book at age 9. Now she is one of Time’s Girls of the YearRebecca Shavit
SpaceDark matter and star clusters work together to reshape the centers of galaxiesJoseph Shavit
DiscoveriesETH Zurich researchers detect a possible fifth force of natureJoseph Shavit
