We all know by now that a sedentary lifestyle — characterized by slouching at a desk or lying in front of your TV — can negatively impact both your mental and physical health. Some researchers have even gone so far to say that sitting can kill you.

Now, new research adds to the evidence that sitting wreaks havoc on our health. The study, published in the Journal of Hepatology, found that too much sitting and not enough exercise increased the prevalence of non-alcoholic fatty liver disease (NAFLD) among middle-aged Koreans. NAFLD is a condition in which fat accumulates in the liver, specifically in people who rarely drink alcohol. In some cases, it inflames and scars the organ, which can sometimes progress to liver failure.

The researchers examined 140,000 middle-aged Koreans who had undergone a health examination between March 2011 and December 2013. They measured their physical activity levels and the presence of fatty liver, and found that some 40,000 had NAFLD. The researchers concluded that more time sitting was associated with an increased prevalence of NAFLD.

“We found that prolonged sitting time and decreased physical activity level were positively associated with the prevalence of NAFLD in a large sample of middle-aged Koreans,” said Dr. Seungho Ryu, of the Department of Occupational and Environmental Medicine at Kangbuk Samsung Hospital, in the press release.

Cases of NAFLD have been increasing in recent years, especially in Western countries. Nearly one in every 10 children in the U.S. have NAFLD, though many patients don’t show any symptoms of the disease. In part, it could be due to the obesity epidemic in the U.S., which affects one in every three adults in the population. The researchers suggest that the antidote is simply increasing your physical activity and sitting less. Indeed, doing so might help prevent a score of chronic diseases, including obesity, diabetes, cancer, and even anxiety and depression.

“The message is clear: Our chairs are slowly but surely killing us,” said Michael Trenell, Professor of Metabolism & Lifestyle Medicine at Newcastle University in the U.K., in the press release. “Our body is designed to move and it is not surprising that sedentary behavior, characterized by low muscle activity, has a direct impact on physiology. With a dearth of approved drug therapies for NAFLD, lifestyle changes remain the cornerstone of clinical care. The challenge for us now is to ‘stand up’ and move for NAFLD, both physically and metaphorically.”

Source: Ryu S, Chang Y, Jung H, Yun K, Kwon M, Choi Y. Relationship of sitting time and physical activity with non-alcoholic fatty liver disease. Journal of Hepatology. 2015.