The Boston Globe reports:
In 2005, Katherine Flegal, a senior scientist studying obesity at the Centers for Disease Control and Prevention, published a counterintuitive paper in JAMA, the Journal of the American Medical Association. Along with a CDC colleague and two statisticians from the National Cancer Institute, Flegal had analyzed a massive government dataset to estimate the number of deaths associated with excess body weight. While the researchers found that obesity was indeed linked to excess deaths, it turned out that people who were merely overweight — plump, perhaps, but not obese — were at less risk of early death than those of so-called normal weight.There is no paradox. A study of life expectancy is going to find an ideal weight for long life. This study merely found that the ideal weight is heavier than what the BMI advocates were saying.
Flegal’s was not the first such study to hit upon this seeming paradox, but it was an interesting result about weight, which is always a hot topic. As the paper’s first author she anticipated fielding a few calls from science journalists. But as she writes in an unusual essay for a forthcoming issue of the journal Progress in Cardiovascular Diseases, “We were unprepared for the firestorm that followed.’’
As that 2005 paper began to get attention, a renowned professor of epidemiology and nutrition at the Harvard School of Public Health, Walter Willett, had already begun his own publicity campaign. Believing Flegal’s findings to be not only wrong but dangerous, Willett and a handful of his Harvard colleagues saw it as their mission to prevent the paper — which Willett deemed “really naive’’ and “deeply flawed’’ — from being taken seriously by other scientists, practicing physicians, or the public.
For more than a decade, Flegal writes, she would find herself the target of “an aggressive campaign that included insults, errors, misinformation, behind-the-scenes gossip and maneuvers, social media posts and even complaints to my employer.’’
From Flegal's essay:
She learned first-hand the antagonism that could be provoked by inconvenient scientific findings. Guidelines and recommendations should be based on objective and unbiased data. Development of public health policy and clinical recommendations is complex and needs to be evidence-based rather than belief-based. This can be challenging when a hot-button topic is involved.For an adult man, it seems plausible to me that a BMI of 25 is healthier than 20.
We see similar controversies today involving covid-19 and vaccines. Our health authorities try to control the narrative, and any other data or views are ostracized.