David Katz MPH ’93, founder of the Yale-Griffin Prevention Research Center and a voluntary clinical instructor at the Yale School of Medicine, is facing criticism this week from doctors and health care professionals around the world for his quoted comments about investigative journalist Nina Teicholz in a recent article published in the Guardian.

The article, “The Sugar Conspiracy” by journalist Ian Leslie, describes the history of research into the causes of obesity, claiming that in recent years, scientific evidence has increasingly shown obesity to be a result of excessive sugar consumption, rather than fat consumption. In response to Teicholz, whose work aims to debunk the idea that dietary fat causes obesity, Katz was quoted in the Guardian’s April 7 article as saying, “Nina is shockingly unprofessional … I have been in rooms filled with the who’s who of nutrition and I have never seen such unanimous revulsion as when Miss Teicholz’s name comes up. She is an animal unlike anything I’ve ever seen before.” Since the publication of the article, several health care professionals have urged Katz to apologize to Teicholz for his comments, both online and in letters to Dean of the Yale School of Medicine Robert Alpern and Dean of the Yale School of Public Health Paul Cleary.

Angharad Powell, a general practitioner practicing in Wrexham, United Kingdom, wrote to Alpern on April 9, accusing Katz of a “highly sexist, personal and vitriolic attack on the character of Miss Teicholz,” and urging Alpern investigate the matter.

In an email to Cleary, Jim Greenwald — a medical director of the SpecialtyHealth clinic in Reno, Nevada — said the comments were “utterly reprehensible,” and expressed his wish that Yale take corrective action against Katz. He added that Katz’s comments were an embarrassment to Yale, which he identified as one of the country’s leading medical institutions.

Gearoid Ó Laoi, a histopathologist who retired in 2009 from the Mercy Hospital in Cork, Ireland, also suggested, in a letter to Cleary, that Katz’s description of Nina Teicholz negatively represents Yale.

“This man needs to be severely censured, and if I were in Yale, I know what I would do,” Ó Laoi wrote in his letter to Cleary.

Cleary declined to comment for this article.

In an email to the News, Katz denied making public comments about Teicholz’s character, and said he has only ever criticized inaccurate content in the public domain. He added that he had no recollection of being interviewed by the author of the Guardian article and did not give permission for the publication of the comments about Teicholz.

“If [the interview] did take place, I certainly did not authorize the use of any such private comments about my personal experiences for publication,” he said. “They would have been explicitly off the record.  Their publication suggests that this journalist was working at the behest of [Teicholz] all along, or in her service, and was willing to violate the ethics of journalism.”

Leslie maintained that Katz’s remarks were made on the record, but could not be reached for further comment Wednesday.

In his email, Katz went on to describe Leslie’s article as “misguided and revisionist science.” Leslie reported in his article that despite requests, Katz did not cite examples of Teicholz’s unprofessional behavior. But Katz said that Leslie never asked him for proof of Teicholz’s behavior. Katz added that he presumed Leslie did not ask him to substantiate his claims about Teicholz in order to write in the article that Katz failed to produce evidence for his comments.

Katz did not respond to request for comment on whether he had contacted the Guardian with regard to the article or whether he felt he owed Nina Teicholz an apology for his remarks.

Frank Hu, a professor of nutrition and epidemiology at the Harvard School of Public Health who sat on the 2015 Dietary Guidelines Advisory Committee with Katz, praised Katz as a “much-valued colleague,” adding that Katz had been outspoken against “special interest groups” who have attempted to undermine the dietary guidelines.

Hu said that in the past, Katz had raised legitimate concerns about Teicholz’s work and qualifications, and that his comments in the Guardian should be interpreted in this context.

Teicholz denied Katz’s accusations that she had influenced Leslie to write the article, calling these suggestions “pure fantasy.”

“I had nothing to do with the Guardian article other than being interviewed for it,” she said to the News. “This line of attack by Katz—to accuse me of being part of a cabal or some kind of master plot—exists only in his own mind.”

Alpern said that Katz is not permanently employed by the University but by the Griffin Hospital in Derby, Connecticut — which is not part of the Yale-New Haven Health System. Alpern added that because Katz is a voluntary faculty member, he is employed on a temporary, year-by-year basis and is not answerable to the Dean’s Office.

Faculty at the Department of Internal Medicine did not respond to request for comment on Wednesday night.

Alpern went on to say that other than in the name of the center, there is no connection between the medical school and the Yale-Griffin Prevention Research Center, of which Katz is the founding director. According to Alpern, the nominal relationship stems from a 1998 decision to attach the Yale name to the center.

Gary Desir MED ’80, interim chair of the Department of Medicine at the medical school and a member of the Ad Hoc Committee on Faculty Standards of Conduct, said that although Katz is a voluntary faculty member rather than a ladder faculty member, he does not condone Katz’s comments about Teicholz.

Desir said that the medical school Dean’s Office investigates each case of alleged faculty misconduct on a case-by-case basis, and he criticized the personal nature of Katz’s comments regarding Teicholz.

“We don’t usually engage in ad hominem arguments, which seems to be what [Katz] is engaging in,” Desir said. “Our faculty engages in vigorous debate, but we also always keep it collaborative. This is not something that we would condone.”

Alpern said that although he is not in a position to judge which scientific basis for obesity is correct, he was unhappy with the negative controversy attracted to the University by Katz’s comments in the Guardian article. He added that he had responded to Powell’s letter.

Katz is a two-time diplomate of the American Board of Internal Medicine, according to his website.

Clarification, April 27: A previous version of this article was unclear about Nina Teicholz’s work regarding obesity.