“What is healthy weight?” Dr. Terilyn Scott-Winful asked at the Black Health Matters Understanding Obesity What Are You Weighing For webinar earlier this year. “When we talk about the Body Mass Index, this index needs to be taken with a grain of salt. When we apply it to the general population, it’s most useful for research purposes.”
Last year, the American Medical Association addressed the prickly past of the BMI’s ascent from the gold standard in evaluating body composition, acknowledging it as an imperfect clinical measure that shouldn’t be used as the lone assessment tool. “The AMA recognizes issues with using BMI as a measurement due to its historical harm, its use for racist exclusion, and because BMI is based primarily on data collected from previous generations of non-Hispanic white populations,” they declared.
However, many physicians still use BMI as a metric in their charting. The BMI not only fails to maintain predictability when it is employed on an individual level, but it also has historical issues baked into its conception. It was not mindfully designed to consider diversity.
Acknowledging that BMI measures height and weight but does not evaluate fat distribution in a person’s body is helpful. Someone with an especially muscular frame could be miscategorized due to the failure of BMI to account for weight that does not fit its narrow limitations. Yale Medicine confirmed that “a person with lots of muscle and minimal body fat can have the same BMI as a person with obesity who has much less muscle.”
Dr. Scott-Winful noted theoretically that BMI may be a good place to begin a diagnosis. They are not comprehensive labels that require no explanation. “These broad categories of underweight, healthy weight, overweight can help serve as a starting point to be able to stratify if a patient potentially has a problem,” the physician certified in gastroenterology and obesity medicine explained.
The AMA recommended that physicians combine BMI with other measurements to assess the health of their patients fully. Doctors can also explain that while BMI is a widely adopted standard against which patient progress is measured, other options can help them understand their health.
Studies show that patients with higher BMIs are less respected than patients with a healthy weight, and physicians report seeing patients who are obese as less compliant and self-disciplined,” according to the British Journal of General Practice. Discussing the merits and the value of the BMI could help promote more effective dialogues.
Body Fat
One of the other measurement tools Dr Scott-Winful uses is body fat. This index changes for males versus females. “What’s acceptable for a female patient may be considered increased body fat in a male patient,” Dr Scott-Winful pointed out. “But it’s also important to note that you can have a normal Body Mass Index and have an elevated body fat percentage and still be pretty unhealthy.”
Waist Circumference
Dr. Scott-Winful’s third assessment with her patients is measuring their waist circumference. “Waist circumference is also an index that it’s important to look at primarily because this is one of the metrics associated with metabolic disease,” said Dr. Scott-Winful.
“Having a waist circumference in general of 35 in women and 40 in men can be associated with increased risk of diabetes, heart disease, and high cholesterol. But it’s also important to note that that changes based on ethnic background,” she continued. So, for black patients, having a lower waist circumference is a cutoff as well as Latino and Asian patients, and this has been demonstrated in studies.”
But there are also some additional diagnostic tools worth exploring that will help physicians assess the health of their patients:
Waist-To-Hip Ratio
The Journal of American Medical Association established that “some individuals store proportionally more fat around their visceral organs (abdominal adiposity) than on their thighs and hip.” Research reported at Stockholm’s European Association for the Study of Diabetes (EASD) in Stockholm, Sweden, suggested that an individual’s waist circumference might better indicate their overall health than their BMI.
This research is still being conducted, but it is a helpful way to illustrate a patient’s challenges. It’s also easy to measure.
Focusing on waist circumference also provides patients with information about visceral fat, which clings to one’s midsection.
Magnetic Resonance Imaging
Harvard’s School of Public Health labeled magnetic resonance imaging, also referred to as dual-energy X-ray absorptiometry, as a more sophisticated option for obtaining accurate body measurements. It provides the nuance that the BMI is missing by accounting for the “measurement of specific body fat compartments, such as abdominal fat and subcutaneous fat.”
There are detractors for this method. It requires expensive equipment, and it can not be conducted on pregnant people. Explain this to your patient if it is inappropriate and suggest other alternatives.
Relative Fat Mass
Scientific Reports published a study “compared with BMI, RFM had a more linear relationship with DXA (dual-energy X-ray) whole-body fat percentage among women.” This makes it a potential tool that could replace the BMI.
Moving beyond BMI will allow you to provide even better healthcare solutions for your patients.
Supported by an educational grant from Novo Nordisk Inc.
