The U.S. adult obesity rate recently reached 42.4 percent, according to the Centers for Disease Control and Prevention (CDC). The agency's data shows that the obesity rate among adults over the age of 20 has increased dramatically over the past two decades. In 2000, it was just 30.5 percent. With nearly half of the U.S. now being considered overweight or obese, there has been warning after warning about the obesity epidemic in the U.S., and the health risks that come with added body weight.
But a new study published on May 7 in the JAMA Network Open has revealed that not all obese people have the same risk of serious health issues. In fact, they found that 40 percent of obese people in the U.S. were not at a higher risk of cardiovascular disease or death. In fact, the study found that people with a body mass index (BMI) of 30 or more, which is considered obese, were found to be "metabolically healthy" if they had three things in particular. Read on to find out what they are, and for more on where obesity is most prevalent, check out The Most Obese State in the U.S.
The scientists behind the new study looked at 386,420 individuals and they found that obese people with normal blood pressure levels, a relatively low waist-to-hip ratio (WHR), and no existing type 2 diabetes were not an increased risk of heart disease or death, leading them to define people who meet these metrics as having "metabolically healthy obesity (MHO)."
The metabolically healthy obese group was found to have systolic blood pressure less than 130 mm Hg and their waist-to-hip ratio was less than 0.95 for women and less than 1.03 for men.
"Our results suggest that people with MHO classified by this definition are not at increased risk for CVD or total mortality," the researchers with the German Institute of Human Nutrition in Potsdam-Rehbrueck concluded.
"Metabolically unhealthy individuals have a substantially higher risk," the study authors wrote. "Thus, our new definition may be important not only to stratify risk of mortality in people with obesity, but also in people with overweight and normal weight."
Ayana April-Sanders, PhD, and Carlos Rodriguez, MD, both of Albert Einstein College of Medicine, shared their thoughts on the study in a commentary published on May 7. They made the case that waist-to-hip ratio is the best way to measure metabolically healthy obesity. "BMI is considered an insufficient measure of body fat content because it fails to account for muscle mass and bone density and does not reflect fat distribution," April-Sanders and Rodriguez noted in their accompanying paper. They say waist-to-hip ratio "is a more effective measurement" that has the strongest connection to cardiovascular disease.
The doctors said the new study gives "much-needed evidence to support establishing a standardized definition of MHO as the first step in understanding obesity phenotypes."
There's been much debate over the term "healthy obesity." A research paper published in the Annals of Human Biology in 2018 argued that the term should not be used. Sharon Zarabi, RD, program director at Katz Institute Women's Health at Northwell Health, who wasn't involved in the 2018 paper, suggested to Healthline that "we need to move away from using BMI as categorizing one as obese/overweight or unhealthy."
"The real debate here is how do we define health? Is the vegetarian who has a BMI of 30, avoiding all saturated fats from meats and consuming a diet heavy in simple carbohydrates [and thus] reducing his risk of cardiac disease but increasing likelihood of elevated triglycerides and insulin, considered healthy?" Zarabi said. "I think we need to redefine health and look at the overall person as a whole, taking into account fitness level, sleep patterns, joint pain, vitamin levels, breathing, strength, happiness, social connections."
And for more ways to monitor your health, If You Can't Do This in 90 Seconds, Your Heart Is in Danger, Study Says.