A group of international experts is proposing a new way to define and identify obesity – a medical condition linked to having too much body fat. The change aims to help doctors better identify and treat affected individuals.
The new proposal shifts attention from a highly debated method called the body mass index (BMI). BMI is a calculation of a person’s height and weight.
The change would mean BMI would no longer be the only way to define obesity. The method would be expanded to include other measurements, such as waist size, and other evidence of health problems linked to being overweight.
Obesity is estimated to affect more than 1 billion people worldwide. In the U.S., about 40 percent of adults are considered obese, the U.S. Centers for Disease Control and Prevention says.
Dr. David Cummings of the University of Washington was one of 58 writers of a report calling for a new obesity definition. The report recently appeared in the publication The Lancet Diabetes & Endocrinology.
“The whole goal of this is to get a more precise definition so that we are targeting the people who actually need the help most,” Cummings told The Associated Press.
The report introduces two new groups, called categories, to help doctors identify, or diagnose, obese individuals. These are clinical obesity and pre-clinical obesity.
People with clinical obesity meet BMI and other markers of obesity. They also have evidence of organ, tissue or other problems caused by too much weight. Such evidence could include heart disease, high blood pressure, liver or kidney disease or ongoing knee or hip pain.
People identified as having clinical obesity would be able to get treatments, including diet and exercise programs, as well as obesity medications.
People with pre-clinical obesity are at risk for the same conditions, but they have no ongoing illness, the report states.
BMI has long been considered a weak measure for obesity. In some cases, it can incorrectly diagnose obesity, which is currently defined as a BMI of 30 or more.
But people with too much body fat do not always have a BMI above 30, the report notes. And people with a high level of muscle mass — such as American football players or other athletes — may have a high BMI even with normal fat mass.
Under the new definitions, about 20 percent of people who used to be identified as obese would no longer meet that definition, early data suggests. And about 20 percent of people with serious health effects – but a lower BMI – would now be considered clinically obese.
Cummings said the new definition would not greatly change the percentage of people defined as having obesity. But, he explained, the new categories “would better diagnose the people who really have clinically excess fat.”
More than 75 medical organizations around the world have supported the new definitions. But it is not clear how widely or quickly the definitions could be approved. The report predicts such changes would carry big costs and have major effects on the workforce.
Dr. Katherine Saunders is an obesity expert at Weill Cornell Medicine in New York City. She also co-founded the obesity treatment company FlyteHealth. She told the AP there are some practical issues to consider in order to make the proposed changes work effectively.
Saunders noted that waist circumference sounds simple, but measurement methods differ. In addition, doctors are trained differently, and standard medical measuring devices are not big enough for many obese people.
Also, a decision about the difference between clinical and pre-clinical obesity would require a full health examination and lab tests, Saunders said. She added that for a new system to be widely accepted, “it would also need to be extremely quick, inexpensive, and reliable."
The new definitions could also be difficult for people to understand or carry out, said Kate Bauer of the University of Michigan School of Public Health. “The public likes and needs simple messages. I don’t think this differentiation is going to change anything,” she said.
Dr. Robert Kushner, of the Northwestern Feinberg School of Medicine, said changing the definition of obesity will take some time. Kushner, a co-writer of the report, said, “This is the first step in the process...I think it’s going to begin the conversation.”
I’m John Russell.
Jonel Aleccia reported on this story for the Associated Press. John Russell adapted it for VOA Learning English.
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Words in This Story
precise – adj. exactly or sharply defined
excess – adj. more of something than is usual or needed
practical – adj. relating to real situations or actions and not to thoughts or ideas
circumference – n. the outside boundary (or perimeter) of a circle
standard – adj. well-established and very familiar; regularly and widely used, available
reliable – adj. giving the same results on repeated tests
conversation – n. an exchange of ideas, opinions, observations, etc.
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