This may at first sound surprising. Often when we think of Type 2 diabetes, we imagine overweight people whose over-indulgence in sinfully fatty foods got them into trouble. But the disease can strike thin people, as well, due to lesser known risk factors.

But while Type 2 diabetes is more common in those who are overweight—that’s the scenario for more than 80 percent of those with the disease—when it attacks those who are thin or even normal weight,  it is even more deadly, according to new study in the Journal of the American Medical Association (JAMA). Factors such as family history, ethnicity, and age (risk for diabetes naturally rises as we get older, possibly because we pack on pounds over the years or because we are less physically active, losing muscle mass as a result) all affect our likeliness of developing the disease.

When Northwestern University researchers analyzed data on more than 2,600 men and women ages 40 and older with diabetes, they found that those who had been recently diagnosed and were thinner (having a body mass index, BMI, between 18.5 and 24.9)  were more than two times as likely to die from heart disease and other causes than those who had been recently diagnosed and were overweight or obese (having a BMI of 25 or more).

This is referred to as the obesity paradox, explained study author Mercedes Carnethon, associate professor of preventive medicine at Northwestern University’s Feinberg School of Medicine, a discovery made through prior research whereby being overweight can offer some protection against heart failure and kidney disease.

According to the findings, the non-overweight groups that developed Type 2 diabetes tended to be older in age and non-white.

Researchers recommend that if you were recently diagnosed with Type 2 diabetes and are slim or at normal weight you should talk to your doctor about controlling your health risks, especially risk factors for heart disease, which is the leading cause of death in the U.S.

They are also quick to point out that the findings do not translate to being able to use excessive weight gain as a viable method to live longer and/or stay healthy, stressing that being overweight or obese overall is far more detrimental to your health than it is helpful. This finding instead suggests that when you are lower in weight at the time you develope Type 2 diabetes, the disease may be more aggressive and your body may also be more susceptible to its damage. Overall, people with Type 2 diabetes who are overweight are still at increased risk of complications.