Many of you reading our most recent issue may wonder how we can even raise the question of whether it’s possible to be both fat and healthy. “There’s scientific evidence!” you might say. “Excess body fat has been proven to be unhealthy.”
Enter this New York Times article from a few weeks ago that discusses how the statistical framework researchers use can influence the trustworthiness of their conclusions:
For decades, some statisticians have argued that the standard technique used to analyze data in much of social science and medicine overstates many study findings — often by a lot. As a result, these experts say, the literature is littered with positive findings that do not pan out: “effective” therapies that are no better than a placebo; slight biases that do not affect behavior; brain-imaging correlations that are meaningless.
This article does a good job of explaining the statistical methods favored by the two sides of the debate (significance testing and Bayesian analysis), but ultimately, most NYT readers don’t know how to use these methods at the end of the day. And here’s where it gets tricky: when we read about scientific research in the news, most of the time we don’t know which statistical method the researchers used. And if scientists disagree about which are the best methods in the first place, and most of us don’t know the difference anyway, how are we supposed to know whether the research we read about is trustworthy?
I’m not trying to cast doubt on every scientific conclusion out there. My main point is simply that “fat is unhealthy” is not, to my mind, a given. Most of us only maintain that because we trust what we read about weight research in the news, but, as the NYT helpfully explains, science reporting and even scientific studies themselves are not infallible. Respected researchers have even called into question a fair bit of medical research, independent of issues around weight. The exact relationship between weight and health remains an open question, one I hope you’ll enjoy exploring in this week’s issue.
(Image by Barbara.K used under a Creative Commons license.)