How to Figure Out Your BMI — And What It Means

Calculating your BMI can help you discover your health risks — and determine whether or not you’re a good candidate for weight loss surgery.

While bariatric surgery can be a life-changing, or even life-saving, procedure for many patients, it’s not right for everyone. That’s why each patient must undergo a rigorous screening process, ensuring that they qualify for the surgery based on a standard set of medical guidelines.

One of the most important of these guidelines is BMI, which stands for body mass index. BMI is a measure of body fat based on height and weight, which can be tricky to calculate and understand. If you’re considering bariatric surgery, here’s what you need to know about your BMI.

Calculating Your BMI

The formula for BMI can be a bit confusing. For calculations in pounds and inches, you must multiply your weight by 703 and divide the result by your height squared. If you prefer measurements in kilograms and centimeters, the formula is a little more straightforward: weight divided by height squared.

Once that you know how the formula works, we recommend simply using an app or specialized online calculator to figure out your BMI. The Centers for Disease Control offer a simple and accurate BMI calculator, as does the National Heart, Lung, and Blood Institute.

It’s important to note that BMI is a metric intended for adult men and women who have already gone through puberty. Because children and adolescents still have a lot of growing to do, adult BMI calculators won’t offer an accurate measure of their health. If you’re interested in calculating BMI for a child or teenager, the Centers for Disease Control offer a different, specialized calculatorfor that age group.

How BMI Relates to Bariatric Surgery

BMI is far from the only determining factor for bariatric surgery eligibility, but it can offer patients some insight into whether they may be possible candidates for the procedure. As a general rule, a BMI of 30 indicates obesity, but bariatric surgery is typically only recommended for patients with a BMI of 40 or greater. This is because people with a BMI over 40 are at risk for serious health problems that may outweigh the risks of surgery. 

That being said, there are some exceptions to the rule. For patients with serious weight-related health problems, such as type 2 diabetes, high blood pressure, heart disease, or sleep apnea, a BMI of 35 or higher may be enough to meet the criteria. In some cases, if the weight-related condition is especially severe, a BMI of 30 may be enough to qualify.

It’s also important to note that though 40 is currently considered the standard threshold BMI for bariatric surgery, it’s possible that this number will become less stringent in the coming years. A study from University of Michigan researchers suggests that patients with a BMI under 40 who undergo weight-loss operations tend to have highly successful outcomes. 

Deciding to have weight loss surgery is a personal choice, but many patients are able to live longer, more fulfilling lives after their procedure. If you think you may be a good candidate for weight-loss surgery and are interested in learning more, contact Long Island Laparoscopic Doctors today.