This metric is a better predictor of heart failure than high BMI, new study finds

Extra belly fat may be a bigger red flag for heart health than body mass index (BMI), according to a new study.

BMI, a screening tool widely used to determine whether people are at a “normal” weight, may not be as useful in assessing health and cardiovascular risk as previously thought.

Researchers found that having higher levels of fat stored around the abdomen was more strongly associated with heart failure risk than a high bodyweight or BMI, according to an abstract presented at the American Heart Association EP Lifestyle Scientific Sessions 2026 on March 17.

Additionally, people with excess belly fat could still be at higher risk of heart failure even if their BMI is in the “healthy” range. The preliminary findings, which have not yet been peer-reviewed, suggest that inflammation plays a major role.

“The most important finding is that measures estimating (belly) fat appear to be a stronger predictor of future heart failure risk than overall bodyweight measured by BMI,” Szu-Han Chen, the study’s lead author and a medical student at National Yang Ming Chiao Tung University in Taiwan, tells TODAY.com.

In the study, researchers analyzed health data from nearly 2,000 African American adults ages 35–84 who did not have heart failure to begin with, per the AHA.

At the seven-year follow-up, 112 had developed heart failure. Higher measures of excess belly fat — including waist circumference and waist-to-height ratio — were linked to a higher risk of heart failure, while high BMI was not, researchers found.

Researchers also found that subjects with higher levels of inflammation (measured via blood tests), were more likely to develop heart failure. Inflammation accounted for about one-third of the link between belly fat and heart failure, per the AHA.

“(This) suggests that abdominal fat is not just a passive storage of energy, but a biologically active issue that can influence inflammatory processes and cardio-metabolic health,” says Chen.

The research may help scientists understand why many people develop heart failure despite being at a “normal” weight, and how to catch excess visceral fat before it becomes dangerous.

BMI vs. Belly Fat

BMI is calculated by dividing weight (in kilograms) by height squared (in meters). For adults, BMI falls into four categories: underweight (less than 18.5), healthy (18.5-24.9), overweight (25–29.9), and obese (greater than 30), per the National Institutes of Health.

“BMI is a simple measure based on height and weight, however, it cannot distinguish between muscle and fat or show where fat is stored in the body,” says Chen.

And all belly fat isn’t equal. There are two main types: subcutaneous fat and visceral fat.

Subcutaneous is right under the skin, which you can feel or pinch, and is considered less harmful for health, per the Cleveland Clinic. Visceral fat is located much deeper in the abdomen and wraps around the internal organs to cushion and protect them.

Some visceral fat is normal, but too much is linked to an increase risk of chronic disease. That’s because it’s made up of fat cells called adipocytes, which secrete hormones that affect metabolism and other processes.

Excess visceral fat can be measured through waist circumference, waist-to-height ratio, waist-to-hip ratio and other tools. These measures better capture fat distribution and are more closely linked to metabolic conditions, Chen notes.

It’s possible to have a healthy BMI yet still carry a risky amount of fat in the abdomen, which can happen when a person has a high body fat percentage and low muscle mass. This pattern, also called “normal-weight obesity,” can still be associated with a higher cardio-metabolic risk, says Chen.

The findings highlight the importance of integrating belly fat measures into routine preventive care for all adults, the study authors wrote.

Belly Fat and Inflammation

Systemic or chronic inflammation occurs when the immune system releases too many inflammatory cells in the absence of injury or infection, which damages healthy tissues, TODAY.com reported previously.

It’s a common risk factor for many chronic diseases. Persistent inflammation can place stress on the heart and blood vessels, contributing to heart failure, says Chen. Inflammation can also “disrupt the immune system,” according to a 2025 scientific statement from the AHA.

Visceral fat tends to be more “inflammatory,” than other types of fat, Dr. Sadiya S. Khan, an associate professor of cardiology and preventive medicine at Northwestern University’s Feinberg School of Medicine, tells TODAY.com.

Over time, excess belly weight can promote chronic, low-grade inflammation throughout the body. “This may partly explain why fat stored around the abdomen appears to be particularly harmful for cardiovascular health,” says Chen.

Khan adds: “The idea is that the more belly fat you have, the more inflammatory risk you have, and that can lead to heart failure.”

This type of excess belly fat is also associated with cardiovascular kidney metabolic syndrome, which refers to the overlap among heart disease, kidney disease, Type 2 diabetes and obesity, TODAY.com reported previously. CKM syndrome is a precursor for heart failure, Khan adds, and it affects millions of Americans.

That’s why the AHA includes a waist circumference measurement in it’s CKM syndrome staging, which is used to identify risk and treat these conditions early, Khan explains.

How To Measure Abdominal Fat

“We’ve known for a long time that weight is important for your health, but weight (or BMI) alone is insufficient to understand your health,” says Khan.

Estimating how much of your weight is fat or muscle, and where this fat is stored, is also crucial. One easy way to do this is by measuring your waist circumference.

Simply stand up and wrap a tape measure around your bare abdomen, above the hips and below the ribs, in line with the bellybutton.

A waist circumference which indicates excess visceral fat and an increased risk is 35-plus inches for women and 40-plus inches for men, per the Cleveland Clinic.

You can also calculate your waist-to-height ratio by dividing that circumference measure by your height. A healthy ratio is up to 0.49; 0.5 or higher indicates increased risk for chronic disease, per the British Heart Foundation.

Waist-to-hip ratio is another belly fat measure, which may predict heart attack risk better than BMI, especially in women, according to an earlier AHA study. To calculate it, divide your waist circumference by your hip measurement. A healthy waist-to-hip ratio is 0.85 or less for women and 0.90 or less for men, TODAY.com reported previously.

“Waist-based measures can provide additional information about cardiovascular risk beyond BMI alone,” Chen adds.

Losing excess belly fat doesn’t happen overnight, but it is possible through consistent lifestyle changes, including: