A new study by researchers at McMaster University in Canada has found that fat stored deep in the abdomen and liver can damage arteries, even among people who appear healthy.
Published in Medicine Communication, the study challenges the continued reliance on body mass index (BMI) as a measure of obesity and highlights the hidden danger of visceral and hepatic fat in contributing to heart disease.
Using advanced MRI scans and data from over 33,000 adults in Canada and the UK, the researchers discovered that visceral and liver fat are strongly linked to enlarged and blocked carotid arteries, which supply blood to the brain and neck. Narrowing of these arteries is a major predictor of stroke and heart attack.
“This study shows that even after accounting for traditional risk factors like cholesterol and blood pressure, visceral and liver fat still contribute to arterial damage,” said Dr. Russell DeSouza, co-lead author and associate professor at McMaster University.
The research revealed that visceral fat was consistently associated with plaque buildup and thicker artery walls, while liver fat had a weaker but still significant impact. These associations remained even after adjusting for lifestyle and metabolic factors.
Experts say the findings call for a shift in how obesity and cardiovascular risk are measured — moving beyond BMI and waist size to include imaging-based assessments of fat distribution.
“You can’t always tell if someone has visceral or hepatic fat just by looking at them,” noted Dr. Sonia Anand, a vascular medicine specialist at Hamilton Health Sciences. “This hidden fat is metabolically active and dangerous, linked to inflammation and arterial damage even in people who aren’t visibly overweight.”
Researchers emphasize that recognizing and addressing hidden fat could be key to reducing heart disease and stroke risks in seemingly healthy adults.
