When I pull aside the mushroom man to ask why he targeted Willett for his pitch, he puts it this way: “My job is to influence the influencers. He’s a big influencer. Harvard is the big name. If they endorse the concept, it’s going to go a long way to making it happen.”
Willett can be just as powerful when he opposes something. Although he is Midwestern polite and never seems to raise his voice, he does speak in a professorial manner that suggests he is very used to being listened to. And when the tenets of his public health worldview are challenged, he can be surprisingly sharp-elbowed. All of which lately has thrust him into controversy.
ON A TYPICAL NEW YEAR’S DAY, the news cycle is slow. But in 2013 it brought the surprising results of a study on obesity, generating headlines like this one from USA Today: “A Few Extra Pounds May Cut Risk of Early Death.” The study, which found that moderately overweight people had a 6 percent lower mortality rate than those of ideal weight, wasn’t funded by some dodgy research front for the fast-food industry. The meta-analysis of 97 previous studies, comprising data from nearly 3 million people, was produced by the Centers for Disease Control and Prevention and appeared in the pages of The Journal of the American Medical Association.
If the general public took the big news as a welcome excuse to ignore the New Year’s resolution offers rolling in from local health clubs, Walter Willett reacted a bit differently. “This study is really a pile of rubbish,” he told National Public Radio, “and no one should waste their time reading it.”
Willett later faulted the study’s author, epidemiologist Katherine Flegal of the CDC’s National Center for Health Statistics, saying she failed to exclude data from smokers and the sick, two groups of generally thinner, higher-risk people that would give the overweight a relative advantage. When Flegal countered that she had adjusted for both groups and found little effect, Willett argued that properly adjusting for them was impossible.
The following month, Willett convened an unusual symposium at Harvard held expressly to discredit Flegal’s study. He even invited Flegal herself to attend. She declined. (“If someone has said your work is rubbish and no one should waste their time reading it, and they’re having a symposium to attack it,” she says, “it didn’t seem like that was something I’d like to go to.”) Willett half considered leaving an empty chair for her on the dais, borrowing the maneuver politicians use to embarrass opponents who refuse to debate.
Flegal’s findings collide with the message Willett has been giving people for years about the central importance of keeping their weight in check. “Next to whether you smoke, the number that stares up at you from the bathroom scale is the most important measure of your future health,” Willett writes in his best-selling book, Eat, Drink, and Be Healthy: The Harvard Medical School Guide to Healthy Eating. Flegal says that as a government researcher, “I feel you put the information out there” rather than try to shape it. “Policy should be based on science, and not science based on policy.”
Willett claims that Flegal clearly has a point of view on this issue. After all, she published a paper in 2005 that reached the same conclusion about the protective powers of a few extra pounds. And he argues that she did a good deal of shaping this time through her decisions about which studies to keep in and which to leave out. Among those excluded was a 2010 study Willett worked on with the National Cancer Institute that clearly found lower life expectancy for overweight and obese people.
For the rest of us civilians, people hungry for a little clear advice, food fights like this one often lead to will-you-make-up-your-minds-already exasperation. If scientists from Harvard and the CDC can’t decide on something as basic as whether being overweight will kill you sooner or later, who are we supposed to believe? And while we wait for the answer, many of us figure we might as well change our order from a side salad to a large fry.
Willett says it’s understandable that people would feel confused about nutrition. Some findings prompt legitimately contradictory impulses: moderate alcohol consumption is associated with lower risk of cardiovascular disease but higher risk of breast cancer in women. Some are reported in a way that emphasizes surprise at the expense of the full story. A recent Institute of Medicine report, for example, found no evidence to support reducing daily sodium consumption to 1,500 milligrams, a point then trumpeted in some news reports as “don’t worry about lowering your sodium.” Yet the study did acknowledge that the average American still uses way too much salt.Continued...