Diabetes is on the rise in the United States, and a new poll looks at where the disease is most and least common.

In the poll, from Gallup-Healthways, researchers surveyed a nationally representative sample of more than 176,000 Americans in all 50 states in 2015. The participants were asked whether they had ever been diagnosed with diabetes in their lifetime.

The three states with the lowest rates of diabetes were Utah, Rhode Island and Colorado. In these states, 7.5 to 8 percent of the survey participants said they had diabetes. In contrast, Alabama and West Virginia had the highest rates of diabetes, with about 16 percent of the participants in those two states saying they had been diagnosed with the disease.

The poll also looked at the rate of diabetes in cities nationwide. The city with the lowest rate of diabetes was Boulder, Colorado, where slightly less than 5 percent of residents said they had diabetes, followed by Bellingham, Washington, where about 6 percent said they had diabetes. The two cities with the highest rates of diabetes were Mobile, Alabama, and Charleston, West Virginia, where more than 17 percent of residents said they had diabetes.

The results were published Wednesday (Nov. 30) in a report from Gallup-Healthways.

“Lower rates of diabetes could point to citizens of a particular state or community practicing healthier behaviors, which, in turn, could lead to better health outcomes and lower incidence of chronic conditions,” Gallup-Healthways said in its report. “But a lower rate could also signal underdiagnoses” of diabetes, the report said.

The overall rate of diabetes in the United States in 2016 was 11.5 percent, up from 10.6 percent in 2008, Gallup-Healthways said. (The 2016 data is based on a separate poll conducted from Jan. 1 through Nov. 6 of 2016, according to Gallup-Healthways.) That means there were about 2.2 million more Americans with diabetes in 2016 than in 2008, Gallup-Healthways said.

The increase in diabetes has paralleled a rise in obesity , which is a risk factor for type 2 diabetes. In 2016, about 28 percent of Americans were obese, which is a nearly 3 percentage-point increase from the rate in 2008, Gallup-Healthways said. Type 2 diabetes has been linked with obesity. Type 1 diabetes, which used to be called juvenile diabetes, is an autoimmune disorder and is not linked with unhealthy lifestyle or diet choices. The Gallup-Healthways survey did not distinguish between Type 1 and Type 2 diabetes.