Nutrition studies used for government guidelines retracted following accusations of 'junk science

The Journal of the American Medical Association announced Wednesday that is has retracted six studies authored by Cornell University food researcher Brian Wansink.

His work influenced government nutrition guidelines including the Obama-era Smarter Lunchrooms program. The papers were retracted by JAMA after investigating claims that Wansink's studies were based on invalid data.

What are the details?

Wansink has published numerous works on portion size, and was influential in guiding federal policies on nutrition for the USDA's Center for Nutrition Policy and Promotion. He was also a brainchild of the Smarter Lunchrooms program launched in 2010, which libertarian Reason magazine called "junk science" last year after pointing to a litany of errors and inconsistencies in Wansink's work.

In May, JAMA received "notices of Expression of Concern" from other researchers questioning the validity of  Wansink's studies. The Journal approached Cornell University and requested an independent evaluation of the professor's research.

In response, Cornell informed JAMA: "We regret that, because we do not have access to the original data, we cannot assure you that the results of these studies are valid."

Wansink responded to the retractions in an email to The Washington Post, saying they came as "quite a surprise."

"From what my co-authors and I believed, the independent analysis of our data sets confirmed all of our published findings," he said.

"What we did not keep over the past 25 years are the original pencil and paper surveys and coding sheets that were used in these papers. That is, once we combined all the data into spreadsheets, we tossed the pencil and paper versions. That might be why they said they couldn't reproduce these from scratch (that is, there was no scratch). As I told my co-authors, I'm very proud of all these papers, and I'm confident they will be replicated by other groups."

What about questionable data?

But Reason's Elizabeth Nolan Brown uncovered several examples of questionable data presented in Wansink's Smarter Lunchrooms work alone, including:

• "The abstract to one of Wansink's published papers claims that schools implementing Smarter Lunchrooms tactics saw a 71 percent increase in apple sales, when the data given in an article table places the actual increase around 4-5 percent
• One Wansink-led paper purports to address the sustainability of Smarter Lunchrooms interventions — yet uses data from an experiment that lasted just one day.
• One published paper lists three different figures throughout (147, 115, and 113) for the number of participants, which should have all been the same, with no explanation."

BuzzFeed reported in February that more than 50 of Wansink's studies were being assessed in what was dubbed the "the Wansink Dossier," resulting in Cornell launching an investigation, retracting five papers and correcting another 14.

Wansink's research has been featured by numerous media outlets including the New York Times, The Guardian,  and O, the Oprah Magazine.