A recent study published in The Lancet recommends that revisions of ethnicity-specific BMI cutoffs are needed to ensure that minority ethnic populations are provided with appropriate clinical surveillance to optimise the prevention, early diagnosis, and timely management of type 2 diabetes.
What is BMI?
Body Mass Index (BMI) is a person’s weight in kilograms divided by the square of height in meters. A high BMI can indicate high body fatness. BMI screens for weight categories that may lead to health problems, but it does not diagnose an individual’s body fatness or health, according to the Centres for Disease Control and Prevention.
Who is at high risk?
Researchers in the United Kingdom discovered that the cutoff BMI number associated with a higher risk of Type 2 diabetes varies between different patient populations. For example, a BMI of 30 or above was linked to a higher risk for white people. For Black people, the cutoff number was 28 or above. For South Asian people, it was 23.9 or above, and for the Middle Eastern population, the BMI cutoff was 26 or above.
Dr Leslie Heinberg, a psychologist and weight management specialist at Cleveland Clinic, stresses the importance of physicians and patients being aware of different cutoff points based on their ethnicity. She explains that the problem is that some healthcare providers might only be making recommendations for diabetes-related lifestyle changes or treatment options based on the risk level for white people. Unfortunately, this means that other populations might not get the medical interventions they need in time.
Dr Heinberg says that BMI can be a pretty blunt instrument for health because it leaves many physical attributes out of the equation.
“It doesn’t consider a lot of things about an individual. You can ask somebody for their height and weight, and it becomes a straightforward assessment compared to a full and comprehensive evaluation. When we think about an individual’s health and health risks, taking their background information into account is helpful. But when you’re looking at a million people, you just can’t do that.”
Signs to watch out for
While BMI is one way of measuring risks, Dr Heinberg says there are other physical clues to watch out for.
“We do know things like waist circumference, waist-to-hip ratio and where you hold excess weight might play an even more important role when it comes to metabolic diseases,” she says. “Also, with things like obstructive sleep apnoea, neck circumference seems to be important. It all goes way beyond just BMI.”
Dr Heinberg says the other important message about BMI or weight is that you do not have to lose a large amount of weight to improve your health.
“There’s this unfortunate message that everyone has to be within this little window. But even a small amount of weight loss — around 2.5kg to 4.5kg — is associated with really significant improvements in metabolic risk or cardiovascular risk.”