Rethinking Protein Guidelines For Optimal Health | Dr. Heather Leidy

**Dr. Gabrielle Lyon** (0:00)
Welcome to The Dr. Gabrielle Lyon Show, where cutting-edge science meets innovation and practical application for everybody. In today's episode, I sit down with one of my favorite scientists, Dr. Heather Leidy. In this episode, we discuss all about dietary protein guidelines, also dietary protein's role on satiation, and so much more. This episode will blow your mind in terms of how the research is conducted and distributed in ways that affect our world. Please join me in conversation with Dr. Heather Leidy.
Dr. Heather Leidy, thank you so much for joining me today.

**Dr. Heather Leidy** (0:47)
Oh, it's great to be here. Thanks for the invite.

**Dr. Gabrielle Lyon** (0:49)
Yeah, well, I've been trying to get you on for, I don't know, maybe a year and a half, but we've done it. And I have to tell you, I have been such a fan of your work.

**Dr. Heather Leidy** (0:57)
Well, thanks.

**Dr. Gabrielle Lyon** (0:58)
I did my fellowship at WashU, Nutritional Sciences out of Sam Klein's lab. And when I started looking at your data, talking about breakfast skipping and adolescence and this nutrition, protein and behavior, it really, really changed everything for me. So thank you so much for all the work that you're doing.

**Dr. Heather Leidy** (1:18)
Oh, well, thanks. It's a great topic. It's been a great area of research for me, and there's still a lot to uncover.

**Dr. Gabrielle Lyon** (1:24)
Yes. Protein, satiety, which we're going to talk all about. You know, your research, you are an associate professor at the University of Texas at Austin. You were at Purdue before and you were at the University of Missouri, right before that. And you've really paved the way when it comes to protein and satiety. You were also part of the 2020 Dietary Guidelines Committee. And I want to start there.
Please tell me a little bit about your role on the 2020 Dietary Committee.

**Dr. Heather Leidy** (1:58)
Yeah. So it was very similar to the other committees in the sense that how you apply. So it was an application process in itself nomination. And so, you know, I was encouraged by a number of folks to give it a go. I'm a physiologist by training, not nutrition. So I ended up stumbling into nutrition for my postdoc. And then have been a researcher in nutrition ever since. And so I submitted my information. And then when I heard back that I was on the committee, it was pretty humbling. It is a daunting task. And there were experts in the field that are on those committees. And so it was, you know, when you first start the process, you don't really know the ins and outs of things. And so I was on two different subcommittees because that's how it works. And then you get to review the entire body of evidence. But it was a year-long process. And, you know, the 2020 was the first time that questions were posed by the public from USDA and HHS. And then it was our job to tackle those. Same thing with 2025 Those questions were already posed. And so, you know, that actually it was different because the other committees, the committees chose the questions to ask. So it was really, I think, a step in making sure that the public were being heard.
But most of the people say with the 2020 guidelines, there was a lot of indeterminate, limited evidence. And so the joke is that what we didn't do a whole lot, and I would say we, I think we did a lot addressing the gaps in the evidence. And so hopefully just making people aware, trying to increase rigor for methodology, adding more criteria that we really should be looking for, even if they're cohort studies or randomized control trials, what is it that we really need to include as criteria to start reviewing that evidence? Because I think that's the tricky part with all science and all evidence. There's bias, but then there's also just limitations with studies. And I think it's important to evaluate that strength of evidence. And so a lot of those topics were yet to be determined. And so the 2025 kind of tried to extend that. Some of the topics weren't covered in 2025, but, you know, it's moving forward. And I would say with the 2020, the biggest thing that I was more aware of now is related to breakfast. And it was the recommendations that then went down to the schools in terms of saturated fat, added sugar, and sodium. And it's going to be a daunting task for schools to try to figure out how to limit that.

**Dr. Gabrielle Lyon** (4:21)