Limitations of BMI

One of the most used tools in bariatric surgery is the BMI calculator. The BMI, or body mass index, and its various cut-off points for normal weight, overweight, and obesity have been around for quite some time and replaced the Metropolitan Life tables that were once the standard for determining whether a patient needed intervention for excess weight. A simple calculation you can find in many weight loss surgery articles or websites is just about all we need to know before deciding whether bariatric surgery is right for one of our patients.

Examples of BMI and Different Treatment Plans

It’s always good to educate our patients on when they should consider bariatric surgery versus, let’s say, the GLP-1 agonist medication that has taken the world by storm over the past year. The approximate cutoff for when bariatric surgery becomes the go-to procedure is around 40. This is classified as morbid obesity, and most public and private insurance covers bariatric procedures at this BMI regardless of comorbidities.

But Is the BMI Accurate?

While BMI is ubiquitous and represents the most straightforward measure of obesity, it is not unreasonable to question its accuracy. First, it does not consider a patient’s gender. Second, muscle mass is also not factored into the BMI – a body builder would be considered obese. Lastly, BMI does not account for a patient’s bone structure. Yes, some people are bigger-boned compared to others.

While insurance companies will ultimately use the BMI as a primary indicator of suitability for weight loss medications or bariatric surgery, we encourage our patients to understand that there are other markers of success as they lose weight.

For one, waist size is an excellent indicator of overall cardiovascular risk. Male patients with a waist size over 40 and female patients with a waist size over 36 are at a higher risk of heart issues.

Bloodwork is also an excellent marker for overall health. Seeing cholesterol, blood pressure, and blood sugar numbers fall after medical or surgical treatment is a great way to measure success and long-term health.

Lastly, how you feel should not be discounted either. If you’re feeling good, you’re making progress!

The Bottom Line

The BMI is the best we have for right now, but it should not be used as the be-all and end-all for determining obesity. Many other factors make up the complete picture of your metabolic health. Please call our office for a consultation to learn more about your weight loss options.