A study by an international commission of scientists, published on Tuesday (14) in the journal The Lancet Diabetes & Endocrinology, suggests redefining what obesity is, advocating for a focus on the amount of body fat and what medical complications a person has, not just their weight.
If the guidelines are widely adopted, they could change doctors’ perceptions of who needs to be treated for obesity. They may also affect the use of prescribed medications that treat obesity. The new definition of obesity has been endorsed by 76 organizations around the world.
The commission proposed that instead of continuing the current use of BMI (body mass index) as a way to define obesity, this number should be a screening tool to determine who should be tested for excess body fat.
The commission stated that people with a BMI above 25 and a lot of fat, but who are healthy, should be left alone. They should be monitored and advised not to gain more weight and possibly lose a little.
Their condition would be called pre-clinical obesity.
Other people with this index and with any of the 18 medical conditions caused by obesity — 13 for children and adolescents — require medical treatment to improve their health and prevent serious organ injuries. Conditions include shortness of breath, heart failure, hip or knee pain, metabolic abnormalities, and malfunctioning organs.
Their condition would be called clinical obesity.
The simplest way for doctors to see if someone has excess body fat is to wrap a measuring tape around a person’s waist, the researchers said. If a woman’s waist is more than 34.6 inches, she likely has too much fat. For a man, the waist limit would be at least 40 inches.
Other tools for healthcare professionals include waist-to-hip ratios, waist-to-height ratios, or DEXA scans, a type of X-ray.
The 58 commission experts spent three years on the study, meeting regularly online. Instead of thinking of obesity as a disease, they wanted to assess it in a different way, said the commission’s chair, Dr. Francesco Rubino, a bariatric surgeon at King’s College London.
But it may be difficult for the new definitions to become commonplace.
BMI is easy to measure — all that is needed is a person’s height and weight. It quickly became the standard for defining whether people were underweight, overweight, or obese.
Moreover, some doctors consider it unrealistic to assume that obesity should not be treated until complications arise.
Finally, using the new standard may also have implications for the use of obesity medications. They are so expensive that some health plans covering them for people with obesity defined by their BMIs may decide not to pay for the medication for people with pre-clinical obesity.
Source: The New York Times