Reader Samantha dropped me an e-mail asking about my opinions of BMI. She is the 35-year-old mother of a 5-month-old infant, recently went in for a check-up, and was told that she was overweight based on the current BMI scale. Her own feelings about what constituted a healthy weight for her body were shattered when she was informed that she needed to be 20 pounds lighter than her own typical weight in order to fall within the “normal” range. And she was frustrated.
I can completely relate to her frustration. Over the past few years, I’ve been having all sorts of digestive and reproductive health problems. None of the docs have had any idea what was up, despite round after round of tests. At some point in there, a blood test came back that had me right on the border of being pre-diabetic. Still nowhere close to being actually diabetic, and that test turned out to be an anomaly. Yet I was told that I should probably lose five pounds to kick me back into the “normal” BMI range. And told this with zero inquiry into my eating or exercise habits. It was all I could do not to laugh in the doc’s face. Really? REALLY? I’m not diabetic, there’s no discernible link between my health problems and my weight, I’m five pounds over “normal,” and you’re still gonna harp on BMI right now?
Now before I really dig into this post, a few caveats. I’m not a doctor, as you all know. I’ve studied human physiology very briefly, but have no experience in the health services or medical professions. Everything contained within this post represents my set of opinions which are based on my personal observations and readings. I don’t know everything about this topic and don’t claim to, but I’ve had experience with it on a very personal level and have formed views accordingly. Samantha asked for my views, and once I began writing my response to her I realized that the topic was worth bringing to this forum. My hope, as always, is to generate a lively, varied, respectful discussion – NOT to assert myself as a weight, health, BMI, or public policy expert. Got it? OK, moving on.
I do not think that BMI is a nefarious tool of purest evil. There are preventable health problems linked to obesity and I understand how a physician might deem it important and necessary to keep patients mindful of weight. On a daily basis, doctors are faced with hundreds of health problems that aren’t preventable, and I think they may harp on obesity because they feel it’s important to practice preventative medicine whenever they can. Also, broken as it is, BMI is one of the only tools we have that provides parameters for understanding when overall weight may begin to impact other areas of bodily function. The idea of having rough guidelines for healthy weight makes some sense to me, especially if those guidelines have been backed up by broad, deep research, and leave room for individual variation.
But in my experience – as supported by my anecdote above – BMI is treated more as a rule than a guideline. Doctors see you’re over a certain number and it’s a done deal: You need to change. I’m sure much of that is related to the high volume of patients that medical doctors are forced to help, how HMOs are organized and run, and other factors that make medical providers feel totally boxed-in. But it’s still harmful and infuriating to the patients. To tell the 35-year-old mother of a 5-month-old to get cracking on that weight loss seems utterly insulting to me. To tell a woman who is five pounds over the magic limit that shaving off a few will cure what ails her seems downright preposterous to me.
BMI is supposed to be more informative and tailored than examining weight alone, but I’m not sure it truly is. Cross-referencing height and weight gives a bit more information, but it’s still not enough for real insight. Certainly not enough to merit application of a broad, health-related label to a highly unique human being. And the scale was developed to study populations, not individuals, which means it has extremely limited application on a person-by-person basis. In my (albeit layperson) opinion, no group of impersonal numbers will give the complete picture of an individual’s health. Not the way an in-depth conversation will.
Do I have a solution? No. I imagine that reexamining the way BMI is calculated to include factors like activity level, fat percentage, bone density, and other key influencers would help somewhat. So would training docs to really TALK with patients about their lifestyles, choices, and overall health before slapping weight-related labels upon them or advising dietary changes. (Which would mean lightening doctor workloads, a potentially impossible demand.) But I really don’t know if either of those would create actual helpful, influential, effective guidelines for linking weight and health, or just circle back to being oppressive, exclusive, rigid, shaming rules.
My understanding is that BMI is a set of guidelines designed to give a rough idea of when your weight may begin to negatively impact your overall health. But like all guidelines, there will be loads of personal variation. Loads. And that’s the piece of the puzzle that ends up missing in a lot of doctor-patient discussions of weight and health.
Image courtesy Beating Down the Dashboard.