Recent research suggests type 2 diabetes, long considered a disease of the overweight and obese, might not need excess pounds to strike.
The study found nearly one in five normal-weight people in this country has prediabetes, a condition that can lead to type 2 diabetes. For folks older than age 45, one-third of those at a healthy weight have prediabetes, the study authors said. People with prediabetes have higher-than-normal blood sugar levels, but not high enough to be considered diabetes.
“Being at a healthy weight may not necessarily be healthy,” said Arch Mainous, a professor of health services research management and policy at the University of Florida and the study’s lead author. “We have some strong data that says we need to rethink our model of what we think is healthy. This may require a paradigm shift so that we’re not just looking for diabetes in the overweight and obese.”
Researchers aren’t suggesting we stop looking at excess weight. That continues to be a significant risk factor for type 2 diabetes, according to the Centers for Disease Control and Prevention. And the American Diabetes Association currently recommends screening for type 2 diabetes in anyone overweight or obese. The ADA also suggests type 2 diabetes screening start at age 45. If that test is normal, screening should happen every three years.
But focusing exclusively on screening mostly overweight and obese people may lead to missed opportunities for early intervention in normal-weight people with prediabetes, Mainous said.
For this study, researchers used data from National Health and Nutrition Examination Surveys, which looked at a nationally representative group from 1988 to 1994 and again from 1999 to 2012. The current study focused on normal-weight people (those with a body mass index of 18.5 to 24.9). In the first half of NHANES, 10 percent of people at normal weight had prediabetes. By the second portion of the survey, that number jumped to 19 percent.
The percentage of people older than age 45 with prediabetes also had jumped, from 22 percent in the earlier study to 33 percent in the later study.
Researchers also looked a waist circumference; a large waist circumference is often tied to type 2 diabetes. About 6 percent of the normal-weight people had an unhealthy waist circumference in the first survey. Nearly 8 percent had a too-large waistline by 2012.
Mainous thinks the unhealthy changes in “healthy” weight people may be due to our ever-growing sedentary lifestyles. “Saying that sitting is the new smoking sounds trite, but there’s a certain level of truth to it,” he said.
The way we measure overweight and obesity may also play a role in the study’s findings. BMI doesn’t look at bad obesity (the type that collects around the belly), experts say. Because of this, Mainous and his team have been seeking alternative ways to screen people for diabetes and other chronic illnesses.
He also stressed prevention. “I want to re-emphasize that diabetes prevention needs to include people at the highest risk who have the most to benefit from intervening, but now we know we have a group that is being missed,” he said. “So, do we need to rethink the guidelines?”