In other words, there is no reason to believe that the trivial variations in mortality risk observed across an enormous weight range actually have anything to do with weight or that intentional weight gain or loss would affect that risk in a predictable way.

How did we get into this absurd situation? That is a long and complex story. Over the past century, Americans have become increasingly obsessed with the supposed desirability of thinness, as thinness has become both a marker for upper-class status and a reflection of beauty ideals that bring a kind of privilege.

In addition, baselessly categorizing at least 130 million Americans — and hundreds of millions in the rest of the world — as people in need of “treatment” for their “condition” serves the economic interests of, among others, the multibillion-dollar weight-loss industry and large pharmaceutical companies, which have invested a great deal of money in winning the good will of those who will determine the regulatory fate of the next generation of diet drugs.

Anyone familiar with history will not be surprised to learn that “facts” have been enlisted before to confirm the legitimacy of a cultural obsession and to advance the economic interests of those who profit from that obsession.