Doctors, please stop using the Body Mass Index.
I recently posted a meme on Facebook that said “According to the BMI chart, I’m too short.” I intended it to raise a laugh, and it did. The joke is that we all know there is something wrong with the chart.
I’m a short 67-year-old with osteoporosis, and I’m getting shorter. I eat a healthy diet that includes lots of fruits and vegetables, I limit my alcohol consumption, and I walk a lot. I’m in pretty good shape, generally speaking. The Body Mass Index chart, though, says I am right on the cusp of being obese.
When the doctor tells you that you are obese the first reactions you have are of horror, shame, and guilt. Everything in our culture tells us that obesity is a terrible thing and it’s all our fault. Neither of those things is true.
First of all, it’s not about your health. You can be fat and healthy. You can be thin and unhealthy.
Secondly, your height and weight are more closely tied to genetics than willpower. Your ancestors had to eat food whenever they could because it wasn’t always available.
The BMI chart was never intended to be used to provide health advice to individuals. It was originally created to map the weight and height distribution of a population of children in the 19th century. Since then we have all become taller and heavier because we have better diets and better health care.
Another problem with the BMI chart that should be patently obvious but isn’t, is that it treats our bodies as if they are two-dimensional cardboard cut-outs. It measures only our height and weight. It neglects to notice that we also have width and depth. It also pays no attention to how fit we are. Duh. So, muscular athletic people are obese according to the BMI, and so are shrinking old people.
It wouldn’t be so bad if obesity didn’t have such a bad reputation. The ‘stupid dad’ character on sit-coms is usually fat. A fat female actress had better be funny or she won’t get any roles in movies. If a fat person is shopping in Walmart they risk having someone taking a video of them and putting it on YouTube, and heaven help them if they are wearing tight pants. Fat people are presumed to be unintelligent, unhealthy, socially inept, and unemployable—none of which is true. Penn and Teller created an episode about this on their series called Bullshit! back in 2007, and it’s still worth a look. (Warning: Language and nudity)
It turns out that the line that the BMI draws to indicate when a person is overweight was reduced from a BMI of 27 to a BMI of 25 in response to lobbying by the pharmaceutical companies who hoped to benefit from selling diet drugs. When the diet drugs didn’t work out, though, the real winners were the food and diet industries. Those of us who think we are overweight go on endless diets, losing then regaining weight repeatedly, and putting money into other people’s coffers in the process.
So, when our family doctor tells us that we are overweight or obese according to the BMI chart, we should not think of that sit-com dad or that Walmart shopper. What we should be doing instead is laughing at the doctor for being so gullible. She or he has bought into the misinformation that is promoted by the food and diet industries, and is perpetuating the mistaken belief that it is scientific. It’s not science, folks. It’s hype. And, it’s wrong.