The ‘Peak Obesity’ Illusion
Taken on its own, the number is astonishing. According to the CDC, as of August 2023, 40.3 percent of U.S. adults—some 100 million people—met the clinical definition for obesity. But this same estimate, which is based on National Health and Nutrition Examination Survey numbers gathered between 2021 and 2023, also seems remarkably low compared with prior readouts. For the first time in more than a decade, NHANES data hint that our obesity epidemic is no longer growing.
The new estimate is almost two percentage points lower than the government’s previous one, which covered the period from 2017 to 2020 and suggested that 41.9 percent of Americans had obesity. The apparent drop has set off a wave of optimism: A recent editorial in The Washington Post, for instance, celebrated the fact that “the obesity crisis might have plateaued or begun to ease,” and in the Financial Times, the data journalist John Burn-Murdoch used his own analysis of the NHANES data to argue that America is already several years beyond its point of peak obesity. Both outlets suggest that this apparent change in public fortune has resulted from the spread of powerful new drugs for treating diabetes and obesity: Ozempic, Mounjaro, and the rest.
The past few years have certainly brought dramatic changes—historic breakthroughs, even—to the treatment of weight-related chronic illness. GLP-1s seem to be effective at improving people’s health, and they’re clearly capable of causing major weight loss. According to a survey conducted by KFF at the end of April, 6 percent of all American adults are currently on these medications, and as supply shortages ease and drug prices come down, that proportion is likely to increase—by a lot. It only stands to reason that, at some point before too long, their effects will be apparent in our public-health statistics. But are they now, already? For all the expectations that are attached to the present age of GLP-1s, the past should be a source of caution. This is not the first time that obesity’s relentless spread has seemed to be abating, and it’s not the first time that such news has fit into a tidy narrative of progress in public health. And so far, at least, claims of peak obesity, like predictions of “peak oil,” have been prone to falling flat.
