The very first edition of “The Joy of Cooking” was self-published by the St. Louis hostess and housewife Irma Rombauer in the first years of the Great Depression. A relatively modest volume, it collected some four hundred and fifty recipes gathered from family and friends, garlanded throughout with chatty headnotes and digressions regarding the finer points of entertaining, nutrition, menu planning, and provisioning. Since that original edition, the book has become one of the best-selling cookbooks of all time. It also has undergone eight significant revisions: Rombauer’s list of recipes exploded into the thousands; entire chapters were added (frozen desserts) and dropped (wartime rationing). (“The” was dropped from the title in the mid-sixties.) The 1997 edition was a particular departure, replete with contributions from superstar chefs and celebrity food writers. “Joy” purists considered it something of a heresy (the Times memorably called it “the New Coke of cookbooks”), and were relieved when the 2006 edition returned to classic form.

Short of that hiccup, “Joy” has been subject to very little criticism in its eighty-seven-year life. Smart, bossy, funny, a little bit cornball, the book has been a staple in countless American kitchens, a go-to gift for newlyweds and recent grads, its adherents spreading the gospel to their own children. (When my parents’ ragged copy of the 1964 edition succumbed to water damage a few years ago, my mother delivered the news as if a relative had died.) About the worst that’s been said of the book is that it’s more useful as a general-reference volume than as a recipe go-to, which—given the cooking world’s overabundance of recipes and its shortage of genuinely useful reference books—is actually sort of a compliment.

So it came as a shock, in 2009, when the prestigious scholarly journal Annals of Internal Medicine published a study under the pointed headline “The Joy of Cooking Too Much.” The study’s lead author, Brian Wansink, who runs Cornell University’s Food and Brand Lab, had made his reputation with a series of splashy studies on eating behavior—in 2005, for instance, his famous “Bottomless Bowls” study concluded that people will eat soup indefinitely if their supply is constantly replenished. For “The Joy of Cooking Too Much,” Wansink and his frequent collaborator, the New Mexico State University professor Collin R. Payne, had examined the cookbook’s recipes in multiple “Joy” editions, beginning with the 1936 version, and determined that their calorie counts had increased over time by an average of forty-four per cent. “Classic recipes need to be downsized to counteract growing waistlines,” they concluded. In an interview with the L.A. Times, Wansink said that he’d decided to analyze “Joy” because he was looking for culprits in the obesity epidemic beyond fast food and other unhealthy restaurant cooking. “That raised the thought in my mind: Is that really the source of things? . . . What has happened in what we’ve been doing in our own homes over the years?”

John Becker, the great-grandson of Irma Rombauer, lives with his wife, Megan Scott, in Portland, Oregon, and they are the current keepers of the “Joy” legacy. When the results of Wansink’s research were released, they and their publishers were blindsided. With the help of Rombauer’s biographer, they posted a response on the “Joy” Web site criticizing some of Wansink’s methods and calling attention to his sample size—out of the approximately forty-five hundred recipes that appear in later editions, he’d chosen eighteen, a mere 0.004 per cent of the book’s content. But they stopped short of rejecting Wansink’s conclusions outright. “Joy” had always been an idiosyncratic operation, written and rewritten, over the years, by strong personalities who held forceful and often conflicting opinions. (Becker’s grandmother, Marion Rombauer Becker, and father, Ethan Becker, were each eventually added as co-authors.) “We assumed that he was probably correct, and that the recipes probably had increased in calories per serving,” Scott told me recently by phone. “If we had wanted to impugn the reputation of a sitting Cornell department head, I think we would’ve found a really tough row to hoe.”

But the study turned up again and again over the years, becoming part of the conventional wisdom on obesity—a “stand-in,” as Becker puts it, for the “Sad American Diet.” A cartoon that was commissioned by Cornell’s Food and Brand Lab and published with the original study depicts a beefy newer edition of the book haranguing an older edition, jeering at its brother, “I have 44% more calories per serving than you do!” Wansink’s tiny sample set, especially, gnawed at the couple. In his study report, Wansink explained the size as a methodological necessity, writing that “since the first edition in 1936, only 18 recipes have been continuously published in each subsequent edition.” But, in researching the cookbook’s ninth edition (scheduled for 2019), Becker and Scott had created an encyclopedic catalogue of thousands of legacy “Joy” recipes, and they counted several hundred recipes that had remained comparable from one edition to the next. When, in 2015, Wansink’s cartoon landed in Becker’s in-box yet again, he decided to conduct his own research. Becker started his analysis cautiously, hoping to find a few counterexamples in “Joy of Cooking” with which to push back against Wansink’s findings. Instead, he told me, “I was, like, ‘Oh, my God, there’s a lot more.’ I mean, the numbers are turning up in our favor, and they’re definitely not determining what Wansink’s got.”

Then, last month, the BuzzFeed reporter Stephanie Lee published a sweeping exposé of Wansink’s research. Academic standards call for researchers to articulate a hypothesis ahead of time, and then to conduct an experiment that produces data that will either prove or disprove the hypothesis. Lee’s article—which was based on interviews with Cornell Food and Brand Lab employees, and also private e-mails from within the lab, which were obtained through a public-records request—showed that Wansink regularly urged his staff to work the other way around: to manipulate sets of data in order to find patterns (a practice known as “p-hacking”) and then reverse-engineer hypotheses based on those conclusions. “Think of all the different ways you can cut the data,” he wrote to a researcher, in an e-mail from 2013; for other studies, he pressed his staff to “squeeze some blood out of this rock.” One of Wansink’s lab assistants told Lee, in regard to data from a weight-loss study she had been assigned to analyze, “He was trying to make the paper say something that wasn’t true.”

Lee’s report wasn’t the first time that doubt had been cast on Wansink’s work: in 2016, he published a blog post (which he later deleted) revealing that he had encouraged graduate students to do this sort of data fishing; the post resulted in a flurry of critical coverage toward his methods. But Lee’s was the most comprehensive and damning account. “Year after year,” she concluded, “Wansink and his collaborators at the Cornell Food and Brand Lab have turned shoddy data into headline-friendly eating lessons that they could feed to the masses.” Two days after Lee’s story was published, John Becker posted on the official “Joy of Cooking” Twitter account, “We have the dubious honor of being a victim of @BrianWansink and Collin R. Payne’s early work.”

Around the same time, Becker sent his own vast archive of material related to Wansink’s study—including a Microsoft Excel spreadsheet tracking the calorie count of hundreds of “Joy” recipes over time—to several academics, including to James Heathers, a behavioral scientist at Northeastern University. Heathers is one of a platoon of swashbuckling statisticians who devote time outside of their regular work to re-analyzing too-good-to-be-true studies published by media-friendly researchers—and loudly calling public attention to any inaccuracies they find. Heathers’s own work—particularly his development of a modelling tool called S.P.R.I.T.E., which allows likely data sets to be reconstructed from published results—has led directly to the amendment or retraction of a dozen academic papers in the past few years, including several authored by Wansink.