The Fat You Can’t See Can Be Most Dangerous to Your Health

3 min read

April 19, 2024 – “Disease.” That’s what Marina Kurian, MD, says she thinks of when it comes to visceral fat.

A little visceral fat – the fat you can't see because it wraps around some of your internal organs – is helpful because it cushions your heart, lungs, and the organs in your gut. But excess visceral fat can excrete more substances called cytokines into your body and bloodstream. Higher levels of these cytokines, also called adipokines, are linked to a higher risk of heart disease, diabetes, and even some cancers. 

So what can you do to prevent visceral fat from becoming a bad player? The same advice generally applies to excess visceral fat as to the more well-known “subcutaneous fat.” When you pinch an inch, that’s your subcutaneous fat. A healthy diet, exercise and, as appropriate, medication and/or surgery can reduce both kinds of fat. 

“The risks from visceral fat can be lowered if we work toward a healthier body weight,” said Ethan Lazarus, MD, immediate past president of the Obesity Medicine Association.

What Do the Experts Think?

There is no easy, reliable way to measure how much visceral fat you have. But experts generally agree that it makes up about 10% of all body fat, so you tend to have more as overall weight increases. Visceral fat health risks are usually linked to a waist circumference greater than 35 inches for women or 40 inches for men. Measurements should be made at the level of the hip bump and across the bellybutton in most people. 

“Visceral fat is bad for overall health,” said Kurian, president of the American Society for Metabolic and Bariatric Surgery and an obesity doctor in private practice in and around New York City. More specifically, she says, it can lead to high blood pressure, heart disease, prediabetes, and fatty liver disease – and can have impact on conditions like sleep apnea. 

Visceral fat can cause systemic inflammation, but there are likely more ways it can cause health problems, said Lazarus, who is an owner of the Clinical Nutrition Center in Greenwood Village, CO. It could be that visceral fat “is promoting diseases like breast cancer, ovarian cancer, or uterine cancer risk through more of a hormonal mechanism. So there's a lot of different possibilities.”

Bariatric surgery was linked to a 32% lower risk of obesity-related cancer and a 48% lower likelihood of dying from these cancers among people with obesity in a 2022 study in The Journal of the American Medical Association. Researchers have linked excess visceral fat to a higher risk of getting 13 cancers, Lazarus said. Another study the same year showed bariatric surgery was linked to reduced heart disease risks, including in people 65 and older. 

Moving Beyond BMI

Body mass index measures cannot give an accurate measure of visceral fat risk either. 

For example, “I see a lot of [White] women in their 60s with a BMI between 27 and 30, and they have sky-high visceral fat based on their other measures, and really high health risks,” Lazarus said. “And I see other people that are younger that have a BMI of 34 and have a low visceral fat.”

“BMI is really letting us down” when it comes to visceral fat, he said. 

Kurian agreed. “It Is not the most accurate in terms of trying to figure out adiposity [excess body fat],” she said, using former New York Giants defensive end Michael Strahan as an example. "[Back] in the day, [he] would have had a BMI around 38 when he was all muscles, but in reality, he was never in danger of needing weight loss surgery," she said. But BMI can be useful as a general guide about overweight and obesity, “so it’s not something we can completely abandon.”

A body composition measurement by a doctor can help assess visceral fat – which Kurian said she offers to her patients. She said providing the numbers from this analysis can help motivate patients.

Of note, bariatric surgery does not remove visceral fat. Instead, the health benefits come from overall weight loss, she said.