A Message from Dr. Christopher Still
Christopher Still, DO, FACN, FACP, Co-Clinical Editor, Bariatric Times; Medical Director for the Center for Nutrition and Weight Management, and Director for Geisinger Obesity Research Institute, Geisinger Medical Center, Danville, Pennsylvania.
In a recent article published in Obesity, authors Drs. Arya M. Sharma and Denise L. Campbell-Scherer discussed obesity as a disease and examined the defining criterion for diagnosis. The authors proposed removing the word “may” from the World Health Organization’s long-standing definition of obesity (abnormal or excessive fat accumulation that may impair health), a change that would help to more accurately diagnose the disease.
Such a discussion leads to further examination into how we currently screen for and diagnose obesity, which inevitably includes the body mass index (BMI). The use of BMI has been a topic of debate for years with critics proposing abandoning it as a measure for obesity. While I personally feel that BMI should not be abandoned as it serves as a good screening tool in population health, I do agree that it should not be considered the best and only diagnostic tool.
If we look at diagnoses of other diseases, we find that specific criterion and not just one measure are used. For instance, no single test can diagnose coronary heart disease (CHD). If CHD is suspected, the health care provider, in addition to examining medical and family histories, patient risk factors, and results of a physical exam, may order myriad testing including the following: electrocardiogram (EKG), stress testing, echocardiography, chest x ray, blood tests, coronary angiography and cardiac catheterization. Using multiple measures allows providers to see the big picture.
Primary care providers who see patients who may have obesity should also strive to see the big picture and answer whether abnormal or excessive fat accumulation is in fact impairing an individual’s health. It’s important to note here that “impairment” can be interpreted as physical (e.g., joint pain), pathological (e.g., high HbA1c), and psychological (e.g., depression). Just as multiple tools are used in diagnosing CHD, so to should be the case in diagnosing obesity. Seeing the big picture is important because while obesity is considered a disease, the disease is not found in every person with what might be considered a high BMI.
Drs. Sharma and Campbell-Scherer state that using an actual measure of health to define obesity would alleviate “misdiagnosing” people who have abnormal or excessive fat accumulation but no health impairments as having obesity. We see this “misdiagnosing” or labeling of patients according to BMI in employee wellness programs where BMI is used as a cutoff point. I serve as Director of the Wellness Program at Geisinger and I frequently see employees struggle to meet their wellness incentive benefits due to BMI. For example, a patient may argue that his or her blood sugar and cholesterol levels are within normal range but they do not get the benefit because his or her BMI is 31kg/m2 and not 30kg/m2.
I think BMI has gotten a bad reputation as it is an absolute measurement that leaves little room for interpretation. It’s come to the forefront in population health with wellness programs and insurance determining who qualifies for benefits or treatment. Available guidelines for diagnoses and treatment of obesity do a good job of including comorbidities or “health impairments” into the algorithm. They also consider research done in certain populations that show comorbidities, such as type 2 diabetes mellitus (T2DM), may occur at lower BMIs.
Redefining obesity is important. It can’t just be BMI. I think the message in redefining obesity is two-fold. First, we should reiterate to our primary care colleagues the criterion in addition to BMI that may be used in diagnosing obesity, including waist circumference and blood testing. Second, we should follow suit of tactics used by organizations like the American Diabetes Association in urging patients to “talk to their doctor.” As we well know, obesity is a complicated disease, but with the right defining and communication tools, we can help get more patients to treatment.
Christopher Still, DO, FACN, FACP
1. Sharma AM, Campbell-Scherer DL. Redefining obesity: Beyond the numbers. Obesity (Silver Spring). 2017;25(4):660–661.