Christopher Gardner says having his research featured in the Netflix food series You Are What You Eat has been one of the more impactful things he’s done in more than 30 years at Stanford.

The show chronicles the experience of four pairs of identical twins who participated in an eight-week study with Stanford Medicine researchers as they compared the impacts of a vegan diet with an omnivore diet. The study involved a total of 22 pairs of identical twins and randomized one twin from each pair to either a vegan or omnivore diet.

“I’m always trying to get people to eat more healthfully, and it often doesn’t work,” said Gardner, the Rehnborg Farquhar Professor and a professor of medicine. “I don’t actually care if they eat a vegan diet, just more plants and less meat. That’s what I’ve been all about for a long, long time.”

Ever since the show’s Jan. 1 release, Gardner’s inbox has been packed with feedback from strangers, colleagues, and others. Gardner’s own sister told him that after watching the documentary, she may try eating more plant-based meals.

The show features several scenes filmed on campus and within the surrounding area.

In the first episode, Gardner explains why it’s difficult to study nutrition when each person is unique. Working with twins, who have the same genetic make-up, helps address that challenge – cue charming shots of twins finishing each other’s sentences and mirroring mannerisms.

Go to the web site to view the video.

Stanford Medicine

The omnivore diet versus the vegan diet: Which one is better for your cardiovascular health? Stanford researchers found the answer by changing the eating habits of identical twins.

Gardner is the senior author of the study, which was co-first authored by Matthew Landry, PhD, a former Stanford Prevention Research Center postdoctoral scholar, and Catherine Ward, a current postdoctoral scholar at the center. Landry is now an assistant professor at the University of California, Irvine.

Gardner spoke with Stanford Report about his experience on the show:


What motivated you to do the show?

There can be this huge, lengthy gap between when science comes up with new findings and it getting implemented in the public, so I’ve become super open-minded as to how we run studies and how visible they are, not only to the public but also to other busy clinicians. Some people do Twitter and some watch Netflix and some go to conferences. These days, if you really want to get your work out there, there are a lot of potential audiences.

It’s totally novel. Ten years ago, we would say, “Social media and videos aren’t credible. We’re academics. We publish, people cite our paper, and we go to conferences.” Now that I am on social media, podcasts, and this documentary, I meet new colleagues, I see papers that I would have otherwise missed, and I’ve been more open-minded to different ways to share the results of our studies.


What has it been like having your study featured in a Netflix show?

Mostly it has been lots of love and lots of people saying, “Congratulations, that’s so cool,” and certainly from a lot of people who probably wouldn’t have heard of the study otherwise. I’ve heard from people who haven’t seen me in a long time, and a lot of colleagues are seeing it and writing to me about it. Then, on the other hand, there have been an overwhelming number of people volunteering to be in my next study. There have also been a number of very challenging communications from people who say, “I’m really sick. I saw your Netflix show and I’m really hoping that you can help treat me,” which is just not possible. I’m not even a clinician. And I’m getting some hate mail from people who don’t believe in plant-based diets, and some conspiracy theorists. So it’s quite a range of responses that I wouldn’t normally get for something published in a scientific journal.

Christopher Gardner (Image credit: Netflix/OPS Productions)

Talk about the upsides and downsides of having a study featured in a show.

I actually think the impact of this is bigger than anything I’ve ever done in 30 years at Stanford. I did the same science I’ve always done, but it’s just presented in a different way. My science doesn’t say people should be vegan; it just says people should eat less meat and more plants. The people who are writing to me are saying they’re trying more plants and trying less meat. That part has been wildly satisfying.

The challenge with the Netflix opportunity was how little control I had. For example, Netflix wanted something in the documentary about exercise and to measure the participants for fat and lean mass, which is done with a very expensive DEXA scan. I pointed out that we didn’t have room in the budget for it with 44 participants. So they said they would do it separately on the side with just eight participants of the study, and it’s well-featured in the show with the eight people who got results. But nobody else got measured by the DEXA, and it’s not part of the study so when people ask for the data, I don’t even have it, but people think I do because of the way it was presented on the show. They also didn’t tell us about the part in which they are measuring for sexual arousal. That was not a part of the study we designed and conducted. I don’t think that was an appropriate topic and only found out about that after the screening.

But overall, it’s been very satisfying to hear that we’ve made more of an impact than I think I ever have before.

Do you anticipate using twins in future nutrition studies?

Yes. I am super excited. Plus the twins are fun. They were wonderful and very easy to work with. They had this sense of humor and were nudging each other and finishing each other’s sentences. They were adorable, which really does sound silly, but it makes it really fun for the staff. When we recruit people for studies, it can be frustrating. If you saw the series you see how much we poked and prodded and harassed them to collect all the data. They could have been annoyed with us. But they all remained friendly and enthusiastic throughout. Only one person dropped out of the study, and then their twin’s data wasn’t useful so the final results are based on 42 out of 44 people. In my field that’s amazing – that’s ~95% retention.

Now that it has aired, what is your favorite part of the show?

I think the show made the science really fun, and because of that, it was more accessible to people learning about it. The film crew and producer did a good job of that. Also, most people who work in this area completely underestimate the recruitment effort. Recruitment is really, really hard in the general population. And within a few days of the Netflix show release, the Stanford Twin Registry administrators called me and told me that their registry had a significant jump in registration. Since the documentary came out, over 300 individuals who had twins signed up to be part of the registry, all thinking how interesting it could be to participate in research studies … and maybe end up on TV?!