In an extraordinary editorial and feature article, Natureone of the world’s pre-eminent scientific journals, has effectively admonished the chair of the Harvard School of Public Health’s nutrition department, Walter Willett, for promoting over-simplification of scientific results in the name of public health and engaging in unseemly behavior towards those who venture conclusions that differ to his.
Willett, who is one of the most frequently quoted academic sources on nutrition in the news media, appears to have crossed a Rubicon when he denounced Katherine Flegal, an epidemiologist at the US National Center for Health Statistics, for publishing a study that showed people who were overweight (but not obese) lived longer than those deemed normal weight. “This study is really a pile of rubbish, and no one should waste their time reading it,” he told National Public Radio.
Flegal had derived this conclusion from a meta-analysis of 97 studies covering 2.88 million people, and it had been published in the prestigious Journal of the American Medical Association (JAMA). What concerned Willett – and other public health experts, who as Nature reported, later staged a symposium to criticize it – was that it seemed to counteract the general message that people should lose weight. As the journal noted:
“Studies such as Flegal’s are dangerous, Willett says, because they could confuse the public and doctors, and undermine public policies to curb rising obesity rates. ‘There is going to be some percentage of physicians who will not counsel an overweight patient because of this,’ he says. Worse, he says, these findings can be hijacked by powerful special-interest groups, such as the soft-drink and food lobbies, to influence policy-makers.”
In other words, Willett's criticism of Flegal's work is based on politics, not science. Science should be free of these petty concerns, just do the work and let the results speak for themselves.