Unlike fat you can see on the outside, visceral fat covers internal organs in the abdomen. People can even look slim but have high visceral fat – and it’s linked with a range of major health issues, including a higher risk of diabetes, stroke, dementia and heart disease.

According to the new study by researchers at the University of Copenhagen’s NNF Center for Basic Metabolic Research – who looked at data from studies involving 1.2 million people who started smoking and over 450,000 lifetime smokers – while smokers often have lower body weights than non-smokers, they also tend to have more abdominal visceral fat.

Smoking isn’t the only lifestyle factor that’s been linked with higher visceral fat. So, could you have ‘hidden’ visceral fat, and should you be worried about it?

What is visceral fat?

Visceral fat is stored deep inside your body around your internal organs, explains NHS GP and resident doctor at MyHealthChecked, Dr Dave Nichols.

“It is different to subcutaneous fat, which is the fat stored under the skin. While some people can have the appearance of being skinny, they can have high visceral fat concentrations, so-called ‘skinny fat’ which puts them at increased risk of cardiovascular disease.”

How do you know if you’ve got high visceral fat?

It can be challenging to measure visceral fat accurately.

“Some people will use waist measurements as a guide, however, there are people who would consider themselves as ‘skinny’, who have a poor diet and have high visceral fat levels,” says Nichols.

“Other measures which can be used include a waist-to-hip ratio, waist-to-height ratio, or BMI. More expensive methods such as CT and MRI scans, or Dual Energy X-ray Absorptiometry (DEXA scans) may also be used in certain groups of people.”

What causes visceral fat?

According to Nichols, a mix of both genetic and environmental (lifestyle) factors causes visceral fat.

“Genetic factors influence how your body stores visceral fat, however, it is the environmental factors that we can have the biggest influence,” he explains. “Environmental factors that affect visceral fat include a poor diet that’s high in fatty foods, smoking, drinking excess alcohol, being overweight and not exercising.

“Some groups are more prone to high levels of visceral fat. These include males, post-menopausal women or those who drink excess alcohol,” he adds.

Why is visceral fat a risk to health?

High levels of visceral fat are an indicator of metabolic syndrome and put you at an increased risk of cardiovascular problems.

“This includes high blood pressure, high cholesterol, insulin resistance and obesity, which then subsequently increases your risk of heart attack, stroke or type 2 diabetes,” says Nichols.

Can you help get rid of it?

Nichols says there are various things you can do to help you keep your visceral fat levels healthy – including getting regular exercise.

“[This should be] at least 150 minutes of moderate-intensity exercise, or 75 minutes of vigorous activity, spread over four or five days per week,” he says.

“Eating a healthy and well-balanced diet” is also important, along with not smoking, avoiding alcohol or drinking within moderation. Nichols also suggests people “avoid sugary foods and drinks, and prioritise sleep” for overall good health.