David Katz SPH ’93 — the Yale-affiliated doctor whose over-the-top Huffington Post review of his own self-published novel caused a furor in the nutrition community last year — has once again tested the boundaries of ethical journalism.

In another column for The Huffington Post over the summer, Katz lambasted the Massachusetts-based supermarket chain Big Y, calling its ad campaign for the In-Vince-Ible Pizza, a fatty snack named after NFL star Vince Wilfork, “deeply disturbing.” He described the pizza as symptomatic of the obesity epidemic in America, and questioned the parenting skills of Wilfork, who appears alongside his son in ads for the product.

“You see, it is not just any pizza,” Katz wrote. “[It represents] carnage in the service of carnivorous palates.”

But nowhere in the May article, which also appeared in the New Haven Register, did Katz mention another crucial detail: Big Y is not just any supermarket. Just one month before the column was published, Big Y cut ties with a nutritional ratings service, NuVal, that Katz established in 2008 and has passionately championed ever since.

Big Y adopted NuVal, a service that assigns numerical scores to food products based on their nutritional value, six years ago as part of an effort to promote healthy eating habits. But last April the chain dropped NuVal because of concerns that its ratings algorithm was out of date. 

In an email, Katz told the News that he has no financial stake in NuVal and claimed he was unaware that Big Y had dropped the service.

“I have no stake in NuVal, other than an interest in seeing it serve the public health to the fullest extent possible,” he said.

He also defended his omission of the NuVal-Big Y connection.

“What do you think there was to disclose?” he said. “I have never had any ties to Big Y, and [my column] was not about NuVal.”

This summer was not the first time Katz has failed to disclose a potential conflict of interest in his biweekly Huffington Post column. In February 2014, he posted a glowing review of a science fiction novel called reVision, which was published under the pseudonym Samhu Iyyam. Katz — who lauded the book’s “lyrically beautiful writing,” comparing it to the work of great authors like John Milton and Charles Dickens — did not reveal that reVision was in fact his own self-published passion project until he was outed by professional rivals online months later.

After the News published an account of the reVision controversy, The Huffington Post retracted Katz’s review. Amazon also took down a similarly florid customer review that he had posted.

Jim Brown, a spokesman for the Society of Professional Journalists, told the News that Katz should have disclosed his connection to Big Y in the May column. But he emphasized that Katz’s latest ethical misstep, first reported by the blogger Peter Heimlich, was less serious than his reVision post.

“I would say The Huffington Post should probably mention that connection, if they’ve had transparency questions about him in the past,” he said. “They should be especially vigilant about that currently and in the future.”

Monica Lee, a communications officer for The Huffington Post, did not respond to numerous requests for comment.

Katz, who has written around a dozen books, is an internationally renowned nutrition expert and media pundit. At Yale, he directs the School of Medicine’s Prevention Research Center, co-sponsored by the University and Griffin Hospital in Derby, Connecticut.

Over the past few years, Katz has become a controversial figure in his field. His work is at the center of an ongoing dispute in scientific circles about federal nutrition standards that affect the contents of school lunches.

Katz has repeatedly denied any financial interest in NuVal, a joint venture run by Topco Associates and Griffin Hospital. At the end of July, in a Huffington Post column devoted to the virtues of NuVal, Katz wrote that years ago he was paid for designing the Overall Nutritional Quality Index, the ratings algorithm on which NuVal is based. But, he added, he has had no financial stake in the company “for quite some time.”

Still, his role in the formation of NuVal — whose website calls him the “visionary” behind the ratings formula — suggests that even if Katz no longer has financial ties to the company, he has at least a personal investment in its success. In 2010, Katz showed up at a Big Y store in Ansonia, Connecticut, to help promote the implementation of NuVal. And in the July column, he wrote that his work developing the ratings index remains one of the proudest accomplishments of his career.

“It’s reasonable to assume he has a lot riding on the project,” said Heimlich, who added that he has counted 16 references to NuVal in Katz’s Huffington Post columns over the past five years.

Katz questioned Heimlich’s interest in his career — Heimlich has written several blog articles about Katz over the past year —and accused him of “trolling.”

Claire D’Amour-Daley, chief communications officer for Big Y, told the News that the chain dropped NuVal because the algorithm is out of date and customers are increasingly able to make savvy nutritional decisions on their own.

When Big Y executives ran across the Huffington Post column, she added, “We didn’t really care.”

“We get hate mail every day, we get love mail every day,” she said. “We aren’t worried about that at all.”

After his reVision article was retracted, Katz posted a long defense of his actions on LinkedIn, noting that “nobody bought the book” as a result of his review. According to D’Amour-Daley, Katz’s criticism of the In-Vince-Ible Pizza was similarly futile. 

“I don’t think we heard about it from customers or anything,” she said. “It certainly hasn’t decreased our sales of the pizza.”

Clarification, Sept. 9: This article has been changed to reflect that Katz has accused Heimlich of “trolling,” not “stalking.”