Is An “Ideal” BMI Real?

Right foot stepping on scale on wooden floor

Almost everything we discuss with bariatric surgeons revolves around BMI or body mass index. While BMI is a handy tool for measuring whether a patient is at an appropriate weight, it is somewhat inaccurate or at least doesn’t consider differences in body types. Very muscular people (for example…a professional football player), may have a BMI that is considered “obese”. However, their muscle mass accounts for their high weight. Further, it doesn’t consider that many patients may be of average BMI, yet they have a significant risk of weight-related medical problems because they have not built proper musculature – a phenomenon known as “skinny fat.”

An Arbitrary Number

Beyond these significant limitations, the BMI cutoffs are fairly arbitrary. There isn’t enough current data to justify the cut-offs of normal weight, overweight, or obesity. However, we know that when patients reach the next threshold, they are at greater risk for weight-related diseases. With that said, some patients with a relatively low BMI may have significant comorbidities, while those with higher BMI’s may have few or none. In general, the higher your BMI, the higher your risk of dying or having a heart attack. If you have more weight-related medical problems, you also have a higher risk of dying or having a heart attack.

So, when talking to Dr. Chang at your consultation, you may find that your target weight is not the same as your ideal BMI. Often, it’s on the lower end of being overweight or the higher end of being normal. This is not to say you can’t push harder to lose those extra few pounds – we all know where we should be and what feels right. Importantly, we want you to shoot for a target weight where your medical problems will be improved or eliminated.

So, the next time you are looking in the mirror or checking your BMI, let’s add a few other ways to gage your success:

  • Your waistline. If you notice you are losing pants or dress sizes, great job! Waist circumference is one of the leading indicators of heart disease because that’s where most of the “bad fat” is stored – around the abdomen.
  • Your blood work results are very telling of your overall health. During your next checkup, if your blood pressure has gone down, your blood sugar is lower, your cholesterol has dropped, and many of your vitamin and hormone levels are within normal range, that’s a huge success that matters as much as your BMI.
  • Lastly, be sure to give yourself the grace of knowing this is a lifelong struggle, and everything will not be perfect. In the months after bariatric surgery, you may gain some weight periodically and plateau here and there. But, as long as you’re going in the right direction, your body and mind will be better for it.

The Bottom Line

Don’t pigeonhole yourself by using the BMI as the only indicator of your goals or success. Understand that losing weight using bariatric surgery or weight loss medication is measured by many different victories, of which weight is only one. Please keep us posted on your progress and ensure you check in with Dr. Chang at your postoperative visits. We look forward to seeing your successes!