What is BMI?
Have you ever gone to your doctor’s office and been told your BMI is too high? Were you curious as to what that means and what you are supposed to do about it? If so, in this post we will explain what BMI is, why it is used, and what the results mean. We will also review other indicators of physical health that can be used to evaluate if your weight is “healthy”.
The Body Mass Index, or BMI, is a measurement tool that was created in the 19th century by a mathematician in an attempt compare the relationship between weight and height. It was not originally created for use in the healthcare industry; however, it has become the most widely used and accepted tool for classifying weight ranges in today’s healthcare system. This is because it is quick to perform during office visits, has low to no cost, and it’s non-invasive.
How is BMI Calculated?
BMI is calculated by dividing weight by height squared. There are numerous BMI calculators, available online to make the calculation easier. Click here to view one. available online to make the calculation easier. The resulting number correlates to a classification of weight and certain classifications, i.e. overweight & obesity, have been associated with an increased likelihood of health problems. (1) See chart below for categories and BMI ranges for adults 20 and older:
https://www.cdc.gov/bmi/adult-calculator/bmi-categories.html
Does a High BMI Determine My Health?
The problem with relying on one measurement to diagnose obesity is that the BMI tool itself has limitations. The BMI tool does not assess body fat percentage or muscle mass. It can not determine the type of fat people have or where that fat is in the body. Abdominal fat percentages are important to identify, “because abdominal fat is associated with insulin resistance, metabolic diseases, and cardiovascular complications”. (2)
There are other tools that providers can use to determine “healthy” vs “unhealthy” weight. One test that can evaluate body composition is called dual-energy X-ray absorptiometry (or DEXA). It can be used to more accurately evaluate the percentages of bone, fat, muscle, and fluid; however, full body DEXA scans* are expensive and not widely available. A cheaper and less invasive test that can be performed is waist to hip ratio measurements (circumference at your waist divided by the circumference at your hips), and abdominal fat measurements to better determine fat distribution. These tests can be performed during a routine office visit.
*Please note that these particular DEXA scans are different from the routine bone density screening tests used to detect osteoporosis.
What Else Impacts My Health?
It is also important to have a provider check your blood pressure and cholesterol levels as elevated blood pressure and cholesterol levels have been linked with cardiovascular and/or heart disease among other conditions. Increasing physical activity can improve your overall health as well as avoiding unhealthy lifestyle habits such as smoking.
Simply having an elevated BMI classification doesn’t necessarily mean you are unhealthy or at increased risk for chronic conditions, but it does mean you should talk with your healthcare provider about your risks and discuss additional tests if necessary to evaluate your overall health. If you feel you may be obese and are interested in medical weight loss trials, contact our clinical trial team for more information to see if you qualify.”
References:
- Center for Disease Control, CDC. About Body Mass Index (BMI) 2024 May 20. https://www.cdc.gov/bmi/about/index.html
- Pray R, Riskin S. The History and Faults of the Body Mass Index and Where to Look Next: A Literature Review. Cureus. 2023 Nov 3;15(11):e48230. doi: 10.7759/cureus.48230. PMID: 38050494; PMCID: PMC10693914.
