Moving too quickly in medicine can be disastrous. The last century is full of examples, from the thalidomide scandal – a morning sickness drug that was never tested on pregnant animals – to the embrace of low-fat diets based on scant evidence. But there is also danger in moving too slowly, and the body mass index (BMI) is an example.
We’ve known for decades that the measure—a simple calculation based on a person’s weight and height—is too blunt a tool, unable to distinguish between fat and muscle or account for global diversity. Its advantages are that it is quick, cheap and easy, but by using it for so long, millions have been wrongly labeled as overweight, a diagnosis with side effects such as being denied fertility treatment and certain surgeries.
But there are better alternatives, and these are finally starting to be adopted. Last year, The Lancet helped catalyze this overdue change by recommending that BMI alone should not be used to measure obesity, a proposal that was immediately taken up by 75 international medical organizations.
This points the way out of wider medical inertia, which comes not only from the much-needed safeguards put in place after the mistakes of the 20th century, but also from a lack of good evidence, clear consensus and the leadership needed to make change happen.
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We need only look to covid-19 vaccines to see that rapid, safe, evidence-based action is possible
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We need only look to the triumph of the covid-19 vaccines, which were produced in a previously unthinkable time frame and saved an estimated 14 million lives in the first year of their use, to see that rapid, safe, evidence-based action is possible.
This type of action is what is needed across many critical areas of healthcare. Better menopause, new psychiatric treatments, more male contraceptive options and new antibiotics are just some of these.
It is right to be careful, but the time has come to move quickly without breaking things.
