Q. Do thin people have to worry about type 2 diabetes?
A. The link between obesity and diabetes is so strong that some researchers even use the term “diabesity” to underscore the relationship. But up to 15 percent of people who develop type 2 diabetes are not overweight. A study published last month in the Journal of the American Medical Association found that normal-weight diabetics had a higher mortality rate than those who were overweight or obese.
Gerald Shulman, a diabetes researcher at Yale University, says that some of these people have a genetic predisposition to the disease, often from a known family history. They inherit genetic alterations that cause their insulin-producing beta cells to stop working properly, leading to high blood sugar.
But for the majority of thin people who develop diabetes, it happens in the same way as in overweight people: they still produce insulin but their bodies no longer respond to it properly, a condition called insulin resistance.
Researchers have found that many thin diabetics have extra amounts of fat in their muscles and liver. This internal “hidden” fat may in fact be more important in contributing to diabetes than the more visible fat under the skin.
“It’s not so much how much fat we have, it’s how the fat is distributed,” Shulman says. Unfortunately, it’s impossible to detect this fat without sophisticated tools used in research. Lean people who develop diabetes, he says, can often reverse the disease by losing fat through diet and exercise, just as overweight and obese people can.