Spending too much time sitting down builds fat around the body’s organs and increases the risk of type 2 diabetes and heart disease.
A study found people who spent a large amount of time sitting down had higher levels of visceral and total abdominal fat.
Visceral fat is unseen and wrapped around the liver, pancreas and kidneys.
Carrying a high amount is known to be associated with insulin resistance – the driving factor for type 2 diabetes, a preventable condition.
Many of us are chained to our desk for work and the research found the most harmful effect was on those who do not work out in their spare time.
The findings are worrying given that most of us now spend more time sitting than retired pensioners, a previous study found.
The new research suggests that while we may not be able to escape being chained to our desks for hours, meeting weekly activity guidelines can make a difference in reducing our risk of preventable disease.
Lead author of the latest study, Dr Joe Henson at the University of Leicester, said: ‘We know that spending long periods of time sedentary is unhealthy and a risk factor for chronic illnesses, such as type 2 diabetes and heart disease.
‘Likewise, the amount of fat deposited around our internal organs may also predispose us to these diseases.’
When it comes to our bellies, we know there’s a difference between subcutaneous fat, the type of fat the lies directly under your skin, and visceral fat, which is unseen and around your organs.
Experts say even slim-looking people can have this dangerous fat on the inside, that’s wrapped around the liver, pancreas and kidneys.
Visceral abdominal fat is also linked to an increased risk of cancer, stroke and heart disease, various studies have shown.
Dr Henson and his team used MRI to scan 124 participants who were likely to develop type 2 diabetes. They also used an electromechanical device called an accelerometers that were placed around their waists to measure how much time these people spent sitting down over the course of a week.
The researchers found that the link between visceral fat and sitting down was strongest for those those who did not meet the public health recommendation of 150 weekly minutes of moderate-intensity physical activity.
Dr Henson said: ‘Using MRI techniques and physical activity monitors we have shown that the more time spent sedentary, the stronger the association with higher levels of internal and abdominal fat.
‘This was particularly so if the long periods of sedentary behavior were uninterrupted.
‘Our findings also show that reaching the […] government’s target of 150 minutes of moderate-intensity physical activity may offer some protection against the harmful effects of prolonged sedentary time.’
The study was published in the journal Obesity.