Belly Fat vs. BMI: Which Better Predicts Your Heart Disease Risk?

• A new study reports that the amount of belly fat a person is carrying may be a better predictor of future heart disease risk than their body mass index (BMI). 
• An unhealthy waist circumference or waist-to-hip ratio may increase your risk of heart disease by up to 50%. 
• Speak with your healthcare professional about how to measure your waist circumference correctly and for health tips to help lose belly fat.  

A new study has found that the amount of visceral, or belly, fat a person is carrying may be a better predictor of future heart disease risk than their body mass index (BMI) alone. 

The results of this study were published in JACC on August 11.

For many years, BMI, calculated from a person’s height and weight, has been widely used to assess whether a person’s weight may pose health risks.

However, measures such as waist circumference and waist-to-hip ratio can provide additional information about body composition and health risks.

“Abdominal fat is the fat distributed within the belly, surrounding the organs of the belly,” explained the study’s senior author, Michael J. Blaha, MD, MPH, director of the Cardiometabolic Clinic at the Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease. “This fat depot is called visceral fat because it is within the viscera (organs) of the body.”

“It is becoming more recognized that BMI is not a great measure of metabolic and cardiovascular risk, [and] BMI is not a great measure of abdominal or visceral fat,” Blaha told Healthline. “Waist circumference and waist-to-hip ratio are good measures of abdominal/visceral fat. When added to BMI, they provide a much better assessment of body composition.” 

High belly fat increases heart disease risk by up to 50%

Researchers analyzed health data from nearly 260,000 people with either waist circumference or waist-to-hip ratio measurements. People included in the study also had one of these heart disease outcomes:  

• fatal or non-fatal heart attack
• fatal or non-fatal stroke
• heart failure
• atrial fibrillation (AFib)
• total coronary heart disease
• total cardiovascular disease
• death from coronary heart disease
• death from cardiovascular disease and/or death from any cause

The researchers discovered that people who were at a healthy weight or who had overweight, and had a clinically defined high waist circumference or waist-to-hip ratio, had a 15% to 50% higher risk for one of the listed heart disease problems. 

“It is important to know that your weight or your BMI is not the end [of] the story,” Blaha said. “Even if you do not have obesity by BMI (i.e., >30 mg/kg2), you may still have considerable abdominal/visceral fat that places you at higher metabolic and cardiovascular risk.”

“The composition of your body matters, not just the weight,” he added. “Our general goal will be to optimize lean body mass while reducing the amount of unhealthy abdominal or visceral fat.”

Why belly fat may increase heart disease risk

Cheng-Han Chen, MD, a board certified interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, CA, who was not involved in this study, told Healthline how too much belly fat may increase a person’s heart disease risk.

“Visceral fat that wraps around the internal organs in the abdomen is particularly known for being metabolically active, releasing chemicals that contribute to inflammation in the bloodstream,” Chen explained. “These chemicals interfere with blood sugar regulation, blood pressure control, and cholesterol levels. These effects then increase the risk of developing cardiovascular disease.”

Blaha noted that experts are beginning to move away from using BMI as the sole measure of weight and body composition, with growing recognition that visceral fat can increase health risks even in people whose BMI does not meet the threshold for obesity.

“Patients with normal weight or overweight can still have high metabolic and cardiovascular risk,” he continued. “New obesity definitions are appreciating this, and are moving toward defining obesity using a combination of BMI and/or multiple measures of abdominal fat like waist circumference and waist-to-hip ratio.” 

How to reduce visceral belly fat

Mir Ali, MD, bariatric surgeon, bariatric medicine specialist, and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, CA, who was not involved in this study, said that while measuring your waist circumference or waist-to-hip ratio is not difficult, there’s a lot of variability. 

“When people measure, not everybody measures it at the same point,” Ali explained. “So sometimes the people who measure it a little higher or lower get an inaccurate number.” 

“So talking to [their] primary doctor to show them the correct way to measure their waist circumference is a way to start,” he added. “And then they could let them know if the waist circumference is abnormal and what can be done about that.” 

When it comes to reducing belly fat, Ali said there’s no way to direct weight loss to abdominal fat. 

“[With] weight loss in general, people will lose it all over, including abdominal fat,” he continued.

He noted there is a misconception that doing sit-ups will help you lose abdominal fat. However, that only develops the abdominal muscles. Unless you’re losing weight, you aren’t necessarily reducing visceral fat.  

“So any kind of a good diet where you’re reducing carbohydrates and sugars, and directing your body toward burning fat, that’s going to help reduce abdominal fat as well,” Ali said.  

“To reduce the amount of abdominal/visceral fat in the body, we recommend that people eat a heart-healthy, balanced diet low in saturated fat and sugar, and high in lean protein and fiber, get regular physical activity, avoid alcohol, get good quality sleep, and limit stress,” Chen added.