This piece is part of our first-annual Health Care Heroes series, where we spotlight people doing amazing things in the health care and medical fields. Read the rest of the stories here.
For 21 years, Kevin Hall, PhD, worked as a senior investigator in the Integrative Physiology section of the National Institute of Diabetes, Digestive and Kidney Diseases—part of the National Institutes of Health (NIH). There he conducted groundbreaking work exploring the relationship between environment and dietary behaviors, more recently focusing on ultra-processed foods and health, including conducting the first randomized, controlled human study demonstrating that a diet high in ultra-processed foods causes weight gain.
In April 2025 he abruptly, and unhappily, retired from the federal agency. Under the Trump administration, he says he had been denied an opportunity to speak freely to the media about his work; forbidden to sign his name to a study that, the administration argued, went against President Trump’s executive order on Diversity, Equity, and Inclusion; and made to fear that any future research that didn’t comport with Health and Human Services Secretary Robert F. Kennedy Jr.’s often bizarre and detrimental views on public health could be hobbled.
Men’s Health reached out to the NIH about these claims; upon publication a Department of Health and Human Services (HHS) spokesperson replied: “It’s disappointing that this individual is fabricating false claims. NIH scientists have, and will, continue to conduct interviews regarding their research through written responses or other means. We remain committed to promoting gold-standard research and advancing public health priorities. Any attempt to paint this as censorship is a deliberate distortion of the facts.”
Currently, Dr. Hall works as a clinical scientist at the pharmaceutical company AstraZeneca, where he helps design early-phase clinical studies to develop obesity pharmacotherapies. He’s also the author of a new book, Food Intelligence: The Science of How Food Both Nourishes and Harms Us. In his own words, below, Dr. Hall tells Men’s Health in detail about his departure from the NIH, its aftermath, and where things stand now.
AFTER I LEFT the NIH, there was initially a lot of interest from academia in hiring me. I won’t name names, but I suspect one school I was talking to eventually decided that I might have a target on my back—that if they hired me the Trump administration might cut their funding out of spite. Not a crazy thought. But most places were very supportive and wanted to do anything they could to help.
I hadn’t just stormed out the door of the NIH. They had a voluntary early-retirement program that cut the eligibility age to 50 if you had at least twenty years of service. So that’s what I did—but that’s not what I wanted to do.
Here’s what happened.
Under the second Trump administration we’d been having trouble buying supplies for our studies, things like continuous glucose monitors—there was suddenly just no ability to purchase vital research equipment. Then we stopped being able to hire research staff and were told to freeze an NIH program for recent undergrads, the Post-Baccalaureate Research Program—these are the folks who do the bulk of the day-to-day work on studies.
Then we couldn’t buy food for our subjects—food being essential for research about nutrition. And it just became, like, what the hell are we going to do?
This was the DOGE era, when federal employees were being strongly encouraged to leave. In my case, I qualified for full retirement, and my family would get to keep our health insurance—that’s a big deal. But first I wanted to see if things at the agency were as bad as I thought they were, and if I could affect change by staying.
The problem was that the HHS leadership was not interested in science.
For example: RFK Jr. had said publicly that sugar is as addictive as crack, but we made an interesting finding that ultra-processed milkshakes that are high in fat and sugar don’t, in fact, cause the same dopamine increase in the brain as other addictive substances like crack, cocaine, nicotine, and methamphetamine. Our paper was very clear: We weren’t saying these foods aren’t addictive. We were just saying that this particular neurobiological process doesn’t operate in the same way as these other addictive substances.
But that little bit of nuance was unwelcome because it contradicted the narrative. First, they didn’t allow me to talk about the findings at a conference, which is the normal thing we would do. Then, after the NIH had prepared a customary press release many weeks earlier, HHS said, nope, no press release. And when a medical journal mentioned the finding in a special issue on obesity, a New York Times reporter requested an interview with me.
And HHS told her no.
They were denying an interview because they explicitly didn’t want communications that in any way challenged the views of the secretary—even though it was so benign. Why did they care if there was evidence that this particular addiction is not working via this one mechanism? It made no sense.
Finally, the HHS said to the Times, Okay, no in-person or phone interview, but you can provide questions and we’ll provide responses. I worked on the answers with my co-authors, and we submitted them to the NIH—but what they sent to the reporter was edited and passed off as if I’d written it. They inserted things like This was a really small study, when in fact it was the largest study of its kind that had ever been done. They downplayed the results. It was not only bizarre, it amounted to censorship.
This was a study that had been finished, written, and accepted for publication before the second Trump administration had come in. Now I was thinking, what’s it going to be like when we try to publish our next finding?
Then there was another paper that mentioned the concept of health equity—the idea that not every American has access to nutritious foods where they live. We were told that this could be in violation of the president’s executive order outlining his policy on DEI, and we were ordered to reword that section.
I refused.
This was all insane. The way things have worked for the almost twenty-two years since I joined the NIH, is: You write your paper, you send it to the institute director, and they basically make sure it doesn’t have stuff that’s beyond the NIH purview. You can’t start mouthing off about policy, things like that. As long as you stick to the science, you’re fine.
Nothing like this had ever happened before.
I had been working with the director of the Office of Nutrition Research on a proposal for how we could get to the bottom of why, exactly, ultra-processed foods are driving obesity and chronic disease—and do it in a much more rapid way than any previous study.
I wanted to do that work, but I also was finding this environment of censorship and control unworkable. I wrote directly to RFK Jr. and the NIH director, Jay Bhattacharya, saying, Look, here are the problems we’re having with our science being hindered. Here’s what we're working on, which is of direct interest to an administration that was waging a crusade against ultra-processed foods. Here’s the censorship that we’ve experienced. I’d love to talk about all these things—and by the way, we’ve been working on a proposal to jumpstart this field of research so that we can get answers to these questions quickly.
I pointed out the impending deadline for me to take the voluntary early retirement—which in a perfect world I didn’t want to do—and said, I’d love to discuss this with you because I’d really like to stay. I just wanted to have a conversation.
No one responded.
My wife could see how pissed I was, and that I felt like I had to leave if I was going to be able to continue my work. But leaving the NIH was a major decision, and financially stressful. It’s not like we’re rich—I was a government researcher and my wife is a Pilates teacher. We knew this was going to hurt.
But it was clear what was happening. The NIH wasn’t just a bunch of woke liberals doing crazy transgender science or whatever the administration might have wanted people to believe. This administration just isn’t interested in science that complicates their narrative. The narrative is all that matters. And while they were meeting with podcasters and social media influencers, they were not willing to even have a discussion with scientists about it.
After I left and my retirement got some press attention, I heard from Jay Bhattacharya—people internally call him “Podcast Jay” because it seems like all he does is go from podcast to podcast—that he wanted to meet with me.
He said he hadn’t seen my email. It had come on I think his second day after he was sworn in, and it got lost. I said, okay, fair enough.
We talked about the censorship I had faced, which he tried to make sound as if it was some kind of bureaucratic mix-up. Then at one point I said, “You’re just starting, and it seems like the only thing that’s happening around here is destruction. People are scared to come into their office, and the DOGE folks are here. Wouldn’t you like to actually build something? Wouldn’t you like to create something?”
That’s when he brought up my proposal to expand this area of research on a faster track—and he said he wanted to work on this with me! He actually said, “Welcome back!” I got right to work figuring out a plan. And then a few weeks later, I learned from my superiors that, abruptly, it wasn’t happening. The project was dead.
I wasn’t coming back to NIH.
It’s chilling to think about how politicized science and science funding have become. To what extent can we roll that back and put in place things that will prevent it from happening in the future? I don’t know the answer. Look, I try to give people the benefit of the doubt. I honestly believe Kennedy is passionate about these issues. He’s convinced himself that he understands the way things work, and he will go out and find any bit of evidence that will support it and then downplay anything that won’t. It’s similar to the way a trial lawyer builds a case: You know what side you’re on to begin with, you build your case around it, and you marshal the most compelling narrative you possibly can.
But that’s not how science works.
Describe your job in three words.
Obesity. Pathophysiology. Treatment.
Favorite medical show to watch?
Lately, The Pitt.
Best career advice you’ve ever received?
Find something you love where your skills can make a unique contribution.
Describe the future of AI in health care in three words.
Unpredictable but promising.
