Think staying skinny will help combat your risk for type 2 diabetes? Not necessarily, says a new study published in the American Journal of Preventive Medicine, which found that people who are inactive may be at an increased risk for prediabetes—even if they’re at a healthy weight, UPI reports.

Prediabetes is a condition that occurs when people have blood glucose levels that are higher than normal, but not quite high enough to be diagnosed as type 2 diabetes. However, studies show that people with prediabetes are far more likely to develop a full-blown metabolic issue within 10 years of diagnosis. According to the CDC, prediabetes currently affects an estimated 86 million Americans across the country.

For the study, researchers at the University of Florida analyzed health data from more than 1,000 people age 20 and older. All of the subjects were considered to be at a healthy weight and had no formal history of diabetes. However, when study authors looked specifically at subjects’ exercise activity, they found that inactive people were significantly more likely to have a blood sugar level of 5.7 or above—which the American Diabetes Association currently defines as pre-diabetes.

Overall, about 25 percent of inactive people, and more than 40 percent of inactive people over the age of 45 were found to be at an increased risk for prediabetes, according to the study.

“Our findings suggest that sedentary lifestyle is overlooked when we think in terms of healthy weight. We shouldn’t focus only on calorie intake, weight or [body mass index] at the expense of activity,” said Arch Mainous III, PhD, the study’s lead investigator and chair of health services research, management and policy at UF’s College of Public Health and Health Professions.

The study doesn’t necessarily prove a direct cause-and-effect relationship between physical activity and prediabetes risk—just a correlation. However, study authors did note that the research may help bolster a growing body of research around the idea of “normal-weight obesity” or “skinny fat” and its potential effects on our increasingly sedentary population.

Click here to learn more about why some skinny people still go on to develop type 2 diabetes.