Kevin Hall, PhD On The Science & Politics of Weight Loss

Kevin Hall, Ph. D., is a physicist-turned-nutrition scientist and author of "Food Intelligence: The Science of How Food Both Nourishes and Harms Us. "This conversation explores why diets fail, the truth behind the "slow metabolism" myth, how ultra-processed foods hijack our biology, and why the 800-pound gorilla driving the obesity epidemic isn't willpower—it's our toxic food environment. He also opens up about his decision to leave the NIH after 20 years due to political interference with his research. Kevin is an honest actor, always trying to set matters to rights amidst a hurricane of nutritional misinformation. Enjoy! Show notes + MOREWatch on YouTubeNewsletter Sign-Up Today’s Sponsors: On: High-performance shoes & apparel crafted for comfort and style👉🏼https://www.on.com/richroll Momentous: High-caliber human performance products for sleep, focus, longevity, and more. For listeners of the show, Momentous is offering up to 35% off your first order 👉🏼https://www.livemomentous.com/richroll Seed: Use code RICHROLL20 for 20% OFF your first order👉🏼https://www.seed.com/RichRoll Roka: Unlock 20% OFF your order with code RICHROLL👉🏼https://www. ROKA.com/RICHROLL BetterHelp: Get 10% OFF the first month 👉🏼https://www.betterhelp.com/richroll Check out all of the amazing discounts from our Sponsors👉🏼https://www.richroll.com/sponsors Find out more about Voicing Change Media at https://www.voicingchange.media and follow us @voicingchange Learn more about your ad choices. Visit podcastchoices.com/adchoices

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

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• 1:06Speaker 01

  Every New Year's, people talk about losing weight. And I always say, "Well, whatever you're gonna do, make sure that you can keep that as part of your life, because otherwise, as soon as you stop doing it, the weight is probably gonna increase." Too often, people around the New Year, and they kind of come up with some New Year's resolution to join a gym, or start an exercise program, or hire a personal trainer, and they tie their success to what's happening on the scale. People will lose weight, and they'll keep it off, as long as they continue that level of effort. And so, yeah, you're right. If people are white-knuckling it and saying, "I'm just gonna do this, and it's a temporary thing, and I'm gonna get to my goal weight, and then I can relax," it's like, "Yeah, that's not the way it works." Nutrition isn't rocket science, it's harder.

• 2:01Rich Roll?

  Well, we're in the thick of it now, aren't we? Right smack in the middle of it. It's all happening, one week out from Christmas, two from the new year. And listen, I'm all for being jolly. I'm here for all the holiday ho, ho, ho. But I actually always find this time of year uniquely challenging. And I actually think a lot of people silently feel this way as well. There are the taut family gatherings, of course, fraught with tension and personality conflicts. And how are we going to do all of that differently this year? Which is something I talked about with Adam Skolnick on the show a couple of weeks back. But at least if you're in the northern hemisphere, there is this interesting conflict between the busy social calendar typical of this time of year, all the parties and the festivities.

• 2:46Rich Roll?

  And on the other hand, what our bodies actually want to do around this time of year? Because winter is the season for hibernation. And I can tell you that what my body wants, from a circadian rhythm perspective at least, is mostly to sequester myself, to kind of hide away from people, go to bed early and just relish a little more silence than normal. I wish I didn't feel this way, but I do. Maybe you don't, but I actually think this is also something that a lot of people feel around this time of year, but actually never say anything about it. Because if you do say something, then you risk coming off like some kind of party pooping bah humbug.

• 3:30Rich Roll?

  So there's this dissonance between the expectations that we place on ourselves and are placed on us by other people financially and socially, and what our intuition is telling us about how to take care of ourselves. All of which creates a bunch of unnecessary anxiety, which of course only exacerbates all of this. And one of the things that I do to help quell this dissonance is I end up eating more than I usually do, which is easier than ever this time of year, of course, leading us wondering what we're going to do about it in the new year. Now, there are no shortage of opinions. On the best way to drop those extra pounds. Lord knows, there are many ways to do this. And I'm actually not here to tell you which strategy is best.

• 4:13Rich Roll?

  But what I am here to do is hopefully provide some added context to your understanding of wellbeing and hopefully spare you from having to sift through a million bad takes. Because you're about to hear from Kevin Hall, one of the world's foremost and most respected nutrition science researchers, who is here today to explain exactly why people struggle to lose weight and keep it off. We talk about the research that he performed that debunked myths about slow metabolism, how ultra-processed foods hijack our biology, why weight loss triggers powerful biological forces designed to push weight back up.

• 4:54Rich Roll?

  We also discuss the surprising science behind appetite, metabolic adaptation, and weight regain, and why environment, not willpower, is the primary determinant of how we eat. We also talk about many other topics, including the full story behind the censorship that Kevin experienced at the hands of the HHS that prompted him to resign his position at the NIH after having worked there for 20 years, which is just an incredible and revealing saga. So if you're looking for clarity when it comes to nutrition and weight loss and what actually drives long-term health, this conversation is an essential listen, as well as one I'd encourage you to share with anyone in your life who is interested in these topics and

• 5:37Rich Roll?

  just starving for good, evidence-based information. Happy holidays, everybody, and now please enjoy me and Kevin Hall. Kevin, so nice to meet you. Thank you for doing this.

• 5:50Speaker 01

  My pleasure.

• 5:50Rich Roll?

  I consider you a very important figure in the world of nutrition science. You're an honest actor, a good-faith actor, always trying to basically set matters to rights amidst a hurricane of nutritional misinformation out there. And I really appreciate your voice and for you taking the time to talk to me today.

• 6:12Speaker 01

  That means a lot. Thanks so much. Some of the audience might be familiar with your name because there was a little bit of a political standoff or kerfuffle several months ago between you and HHS and RFK Junior, which resulted in you resigning after 21 years at the NIH. And that created a bit of a media circus. I do want to know about that, but we're not going to start with that.

• 6:38Rich Roll?

  As somebody who has been studying metabolism for decades, top level, like what are the conclusions that you've drawn from the randomized controlled trials that you've performed about the relationship between metabolism, weight gain, and weight loss?

• 6:55Speaker 01

  Yeah, so when people are losing weight and they are decreasing their body size, either by, you know, an exercise intervention, a diet intervention, a pharmacotherapy or something like that, they tend to, at rest, their resting metabolism, when they're not moving, is decreasing. Now, it seems to decrease even more than you'd expect, at least transiently, while they're in active weight loss, compared to what you'd expect for their decreasing body size. Larger people burn more calories than smaller people, so it goes to figure that as you become smaller, you burn fewer calories. But it turns out, in the process of becoming smaller, during that period, when you're actively losing weight, it seems like metabolism slows even more than expected.

• 7:40Speaker 01

  This is something called metabolic adaptation. One of the most extreme cases of this was seen in volunteers in Minnesota who volunteered for a starvation experiment by Ansel Keys back during World War II. The idea was they volunteered to serve their country, they were conscientious objectors, and they basically said, "We're going to starve because eventually the war is going to end and we need to learn how to refeed all these people in Europe who have been subject to starvation during the war." And so these folks basically were relatively lean to begin with, and 36 people underwent like a 50% calorie restriction. And you could just see their resting metabolic rate falling, and it went down much more than

• 8:23Speaker 01

  you'd expect based on how much weight that they lost. A similar sort of thing was observed by us when we examined these folks in this Biggest Loser television competition. We saw that while these folks were doing insane amounts of exercise and cutting their calories and their diets, their metabolic rate was slowing by a huge amount as well during this program.

• 8:43Rich Roll?

  And it stayed slow long after.

• 8:46Speaker 01

  Yeah, and that's something that's still a little bit mysterious, to be honest with you, because unlike the Minnesota experiment folks who they did have their refeeding phase and they did regain some of their lost weight, their metabolic rate improved. It actually went back up towards normal. And most sort of weight loss trials that have looked at people, and unfortunately, many people who lose weight via lifestyle intervention end up regaining some of the lost weight. Those folks tend to recover their resting metabolic rate as well. There's something really weird about what happened in the Biggest Loser study. And we have some theories about what that might be. It might be that there's something about the fact that these folks actually started off very sedentary.

• 9:29Speaker 01

  They became very extraordinarily physically active during the program, exercising three hours every day, seven days a week vigorously. And then even when they went home during the weight loss competition, it was an hour a day of vigorous activity. Even six years later, they were pretty darn active compared to where they started. So is there some trade off going on between if you become that physically active, does something else in metabolism slow down to compensate? That's a theory at this point. We don't really have good data. And unfortunately, it's a hard experiment to repeat, right? Unfortunately, the television show's canceled, so I can't just go back and do that because it was a bit of a train wreck for a television show, to be honest.

• 10:13Speaker 01

  But yeah, something interesting was going on there that I don't think we fully understand.

• 10:16Rich Roll?

  Yeah, so correct me if I'm wrong, but essentially with this Biggest Loser study, the conventional wisdom or the expectation was that metabolic rate was going to correlate pretty tightly with people who regained the weight. Like you would be, there would be a correlation between metabolic rate and the people who regained the weight and the people who are able to, you know, maintain their new lower weight, correct? And the results actually defied that on some level.

• 10:43Speaker 01

  Yeah, so there were several things that were surprising about the results. One was that you would think that the more you slowed your metabolism, the less you'd be able to lose, the less weight you'd be able to lose, because after all, that's kind of physics, right? If you were burning more calories and you cut the same number of calories in your diet, then you would expect to lose more weight. Like, the energy has to come from somewhere, it's going to come from body fat. What we observed in The Biggest Loser was that the people who were most successful at losing weight during this kind of crazy competition, they were the ones who experienced the most slowing of metabolism. So that was kind of weird. It was like, okay, what's going on there? Why it seemed to be completely, the expected correlation was flipped.

• 11:25Speaker 01

  And then there is this idea that the slowing of metabolism, well, that's got to be a bad thing, that's got to predict who's going to regain the most weight after this crazy competition. And there turned out to be no significant relationship whatsoever with who regained the most weight. It wasn't the folks who had the greatest slowing, it wasn't the folks who had the least amount of slowing, it was more or less random. And then, six years later, the ones who were most successful at keeping the weight off continued to have the greatest slowing of metabolism. And the only way I've been able to sort of make sense of that is that our changes in metabolism, the slowing of metabolism, is a response to the intervention. It's not determinative. It's the way I sort of like to think about it is it's kind of like the tension on a spring.

• 12:10Speaker 01

  And if you're doing an intervention to stretch the string, that's the spring, and thereby kind of cause weight loss, you know, you can do that, but the greater pullback you'll feel, right? But the greater you pull, the more weight you've lost. So the distance that you pulled the spring is, in some sense, related, it's like how much weight you're losing, but the more you pull, the more the resistance, the greater the tension on the spring, that's the metabolic slowing. Clearly, if the spring had less tension, you'd be able to pull it further, right? But the point is, is it's not determinative of how long the spring is, it's how hard you're pulling on the darn thing, right? So whatever lifestyle intervention these folks were able to do, both on the television

• 12:51Speaker 01

  program, as well as after they went home, that's going to be determinative of how much weight they've been able to keep off. And the slowing of metabolism, while not helpful, it's really an indication, it's kind of like the cart, not the horse, right? It's the follower, and it's the response to that intervention.

• 13:11Rich Roll?

  On some level, it makes sense that somebody who is attempting to lose weight, and perhaps even a dramatic amount of weight, that physiologically, the body would respond by slowing metabolism, because it will interpret that as a threat. Like, "We gotta hold on to this weight. This guy's trying to starve us. Let's keep this fat here, because we might need it," as a sort of evolutionary adaptation.

• 13:35Speaker 01

  Yeah, I think that that makes sense if you're lean. But once you cross a certain threshold, like, how long do you really have to prepare for starvation? Most people, so, humans are apes that actually store quite a bit of body fat compared to other apes. Like, even lean humans have quite a bit of body fat. We talk in the book about, like, most people have enough body fat on them to last for months. You know, starvation periods that last for longer than months, most people are not dying of losing body fat, they're dying of the infections and the propensity for infections that come along with that. And it's not clear if body fat is protective of that or not.

• 14:18Speaker 01

  So I sort of expected that maybe we wouldn't see this if we were studying people with obesity, because they're way above the necessary requirements.

• 14:27Rich Roll?

  No alarm bells need to go off.

• 14:29Speaker 01

  Exactly, but it seems like it's the same alarm bells. And how that works is really interesting to me. I expected, like, clearly, the Minnesota starvation folks, who were like 67 kilograms on average, so pretty lean by today's standards, yeah, they're losing, and when they're losing weight, they're losing mostly lean body mass, they're not losing as much body fat, because they start off with very little amounts of body fat. So clearly, that's a case where, gosh, yeah, the alarm bell should go off, you should slow down metabolism a lot, but you're starting off with a lot of stored energy. It's kind of like, it'd be like your phone going into power-saving mode, even though it was at 98% energy, right? You only really think that that should kick in after you get to 10%, right?

• 15:11Speaker 01

  But it seems like, for whatever reason, people with obesity seem to have the same sorts of responses to that acute challenge that is causing a calorie deficit. And whatever that is, you're right, they sort of respond to that challenge by saying, "Yep, no, we're slowing things down, we're going into power-saving mode." And I don't think we fully understand all of the mechanisms by which that happens. Some of it has to do with the sympathetic nervous system and slowing of that, but yeah, I don't think we fully understand it.

• 15:42Rich Roll?

  Yeah, I mean, what is your sense of where the answer lies? Like, is it in genetics? Is it in the microbiome? Is it in the hormonal system?

• 15:50Speaker 01

  Yeah, I mean, my sense is that it's probably mostly in the hormonal system. One of the things that we found was that the relationship between the slowing of metabolism was related to how much the hormone leptin changed. And leptin, even though it's in a person who's kind of just maintaining their weight, it's proportional to how much body fat that they have. When you take a person, even with obesity, who starts off with a very high amount of leptin, even though they haven't lost very much body fat yet, and you put them into this energy deficit, leptin levels crash. So it seems like that metabolic slowing is not sensitive necessarily to the absolute amount of leptin that's there, but the change and the decrease that takes place. That's a hypothesis. I don't think we have a good experimental investigation of that yet.

• 16:35Speaker 01

  There's folks like Rudy Leibl and Michael Rosenbaum have done some experiments where they actually kind of try to infuse leptin at different levels to try to prevent that. And they've seen that it seems to be successful at preventing the reduction in energy expenditure, especially at low levels of physical activity, where a good chunk of our energy budget goes to. So those are kind of interesting experiments that suggest that that might be the case. But again, I don't think that they're completely determinative either.

• 17:03Rich Roll?

  And what do your findings suggest about the malleability of our metabolic rate? Like, how much agency do we have? Like, oh, okay, my metabolism is slow. Like, what can I do? I'm going to kickstart it. I'm going to hyperdrive it. You know, like, do we, can we insert ourselves into this equation to, you know, drive a certain outcome here?

• 17:24Speaker 01

  I mean, there's lots of promises, right? There's lots of promises that certain supplements can increase metabolism. And the evidence behind those is, well, yeah, maybe you can detect a statistically significant change in metabolism, exposing yourself to a larger amounts of these kinds of supplements, but it's pretty clinically meaningless. The times that we've actually, the only time we've actually come up with really good ways of speeding up people's metabolism, this was again in the sort of turn of the 20th century. There was a compound that was discovered in a munitions factory during World War I, where people were spontaneously losing weight and were like, what's going on?

• 18:08Speaker 01

  It turns out that they were exposed to something called dinitrophenol, which turns out to be an uncoupler of mitochondria. So it actually prevents the mitochondria from functioning properly, not making as much ATP as they should. And as a result, metabolism, exactly. Interesting. And it turned out to be extremely effective for weight loss, but also incredibly dangerous. In fact, one of the first things that the newly formed FDA did was withdraw dinitrophenol from the medications that were allowable for use because it was so dangerous. Many people were dying and it's actually not very encouraging to see that there are still some bodybuilders out there that are kind of obtaining dinitrophenol for cutting for, you know,

• 18:53Speaker 01

  for competitions and things like that. It's still available, but yeah, it's not safe.

• 19:00Rich Roll?

  What about exercise and/or like nutrition timing? Like what is the difference between kind of grazing lightly throughout the day versus, you know, an intermittent fast? You know, it would seem to me that these things would, you know, both of these things would have a significant impact on metabolism. Would they not?

• 19:19Speaker 01

  So I think we have to separate out some of the things that we talk about in terms of like resting metabolism. That's kind of things that you're doing when you're not eating anything and you're not moving around, which is one of the things. That's what we were primarily measuring in The Biggest Losers. And when we were talking about metabolic slowing, that's what Ansel Keys was talking about in The Minnesota Starvation Folks, the kind of sort of basal metabolic rate. Yeah, if there is an effect of exercise and those things, it tends to wash away after, like, there's a period, like, hours, many hours after your exercise, where it seems like there is some residual response, but that seems to go away.

• 19:53Rich Roll?

  You'll go back to that same basal rate.

• 19:56Speaker 01

  Yeah, yeah, but there is a period, like, if, yeah, after you feel like you've calmed down from your exercise, if I was to measure your resting metabolic rate, it would indeed be higher, but we're not talking for days, we're talking hours after exercise. But, of course, there's the energy expenditure of exercise, right, which is also part of the total calories that you're burning, and obviously that goes up. There's some controversy about how much compensation in other aspects of your physical activity, like, if you go for a run, do you not fidget as much afterwards, or something like that, and what degree of compensation is there? And then there's even the compensation that could be potentially theorized that may have been what we saw in The Biggest Loser, folks, right?

• 20:39Speaker 01

  They had now appreciably increased their physical activity energy expenditure. Is that one of the reasons why we saw the reduction in resting metabolic rate? It was certainly, those two things were correlated with each other, but again, I don't think that we have good evidence of that. But that is one obvious thing that you can do to increase your overall calorie expenditure is to increase your physical activity. To what degree? Some people compensate for that with other parts of their energy budget, I think, is something that there's some debate about right now.

• 21:08Rich Roll?

  And you can't decouple that from increases in appetite as a consequence of more exercise or, you know, whatever kind of, like, diet you're on that might have that whiplash effect on appetite increase later.

• 21:23Speaker 01

  Right, and, I mean, in fact, it's really interesting that there is this coupling, right, because we do regulate our body weight, and appetite and expenditure are these coupled processes that are, that somehow influence each other.

• 21:37Speaker 01

  You know, there's a lot of talk about cold plunges or actually spending a lot of time in cold water and things like that. Interestingly, the few studies that have done cold exposure in these kind of respiratory chambers where we can measure oxygen consumption, carbon dioxide production, those folks, yes, they have an increase in calorie expenditure. Some of it is from shivering, some of it is from brown adipose tissue, this brown fat that's specifically evolved to kind of heat us up. It's more prevalent in leaner people and less prevalent in people with obesity. Certainly, younger people, more young people have it than the most that you'll ever have is as a baby. But it turns out that when you do those kinds of exposures and you can increase the total number of calories that

• 22:21Speaker 01

  people are burning and you let them eat whatever they want, they actually overeat the calories so that they will happily compensate for those increased calories from expenditure.

• 22:31Rich Roll?

  The caloric expenditure in that context is pretty de minimis, though, also.

• 22:36Speaker 01

  Yeah, it depends how you do it, right? I mean, if you actually induce shivering, it can be pretty darn high. I mean, it's not a comfortable feeling by any stretch of the imagination. So there's like, people do studies where they kind of try to ramp up the temperature slowly and try to get you into a range where you're experiencing the non-shivering thermogenesis. And yeah, that tends to be pretty minimal, but once you get to the shivering mode, yeah, your energy expenditure goes up quite a lot.

• 23:02Rich Roll?

  Interesting.

• 23:03Speaker 01

  So yes, also turns out to be pretty darn comfortable to do that for a meaningful period of time. Sure, a short period of time. And yeah, you look at the rate of energy expenditure is very high, but you're only doing it for a short period of time. So it's not really a kind of a weight loss tool because over the course of the day, while there's many, many more hours of the day, you can compensate it for it by eating more, you can compensate for it by changing other parts of your energy budget. So it's not exactly clear. But I think that one of the ways that I thought was most interesting to kind of look at this coupling between calorie output and appetite was a study that my colleagues did when they were testing a new type 2 diabetes drug that essentially works on the kidneys and increases output of glucose. And it does, and they did this

• 23:48Speaker 01

  placebo-controlled trial in people with type 2 diabetes and they're able to kind of have folks...

• 23:56Speaker 01

  Many hundreds of calories are being spilled in the urine of these folks. And of course, they don't know it unless they're tasting their urine to see if it's getting sweeter. I don't think that's a common phenomenon. So there's placebo group and this folks that are randomized to this drug that's spilling excess calories in the urine. And if you actually look to see what happens, yeah, they lose weight, but they don't lose anywhere near as much weight as you would expect, just based on the calories that were spilled in their urine. And so we did some work with, with the folks at this drug company to figure out, well, how much were they actually compensating for? We're not talking about days, we're talking about happening over months. Over the course of a year, they eventually almost completely compensate for the lost calories

• 24:36Speaker 01

  by increasing their calorie intake above baseline by several hundred calories per day. So that they plateau at a lower weight, but it's only about four or five kilograms lower than they were to begin with. If you'd actually just, if they just kept eating the same amount, they would have lost, you know, triple that amount of weight.

• 24:54Rich Roll?

  Yeah. So what do you make of that?

• 24:56Speaker 01

  So it tells me that there's some coupling between calorie expenditure or loss of calories from the body in terms of either you're peeing them out or you're expending them through, through physical activity or exercise or resting metabolic rate. And the weight change that is occurring is somehow a feedback system to the brain to very gradually and subtly over many, many days and months shift upwards the number of calories that people are eating. And we tried to quantify that and relate it to what's the degree of overall calorie slowdown that people experience when they lose weight. And it turns out to be a much stronger effect than the slowdown of calorie expenditure.

• 25:37Speaker 01

  So if you kind of quantify it, for every kilogram of weight that you lose, your calorie expenditure goes down by about 25 calories per day. So you lose, you know, 10 kilos, 22 pounds, you'll be burning about 250 calories per day lower than you were before you'd lost that weight. Appetite seems to go up by about 95 calories per day.

• 26:00Rich Roll?

  So it's going to outpace that?

• 26:02Speaker 01

  Yeah. And so the plateaus in weight that we see when people kind of experience that in concert with a lifestyle change, for example, you cut calories in people's diets. Part of that plateau is because of the metabolic slowing, the smaller body, burning fewer calories, but the vast majority of it is because appetite has gone up to compensate. And people don't report that, right? They actually don't report their food intake increasing. Like, if you ask them to kind of do a 24-hour recall of, what are you eating in the first month of your diet versus at 12 months after you've stopped losing weight? Those numbers are actually quite similar. But by all objective measures, their calorie intake has climbed

• 26:43Speaker 01

  substantially. Maybe not quite up to baseline, but it's climbed substantially. And the way I like to think about it is that these folks are reporting not their absolute number of calories, they're reporting how hard they're still working to maintain that lifestyle intervention and that degree of effort that they're putting in. And I think that is probably pretty consistent. It's just that they're fighting a greater and greater battle, the more weight that they lose. They're basically, the weight loss per se is causing their appetite to increase, it's causing their energy expenditure to go down. And despite that constant effort that they're putting in, they finally equalized. The biology has equalized whatever the effort

• 27:24Speaker 01

  was that they put in. And so now, weight plateaus, and I think many people get the experience of, well, what the heck am I putting in all this effort?

• 27:33Rich Roll?

  Yeah. I mean, we're painting, we're painting sort of a bleak, you know, disempowering picture here. It's almost as if, you know, the body has this homeostatic set point, and no matter what we do to try to find a workaround, it will, it has a crafty way of making sure that it returns to that homeostatic point where-

• 27:52Speaker 01

  But doesn't fully return, right? That's, I think that's the point, is that people will lose weight and they'll keep it off as long as they continue that level of effort. Now, whether or not they're satisfied with that amount of weight loss, whether or not it's meaningful for them from a psychological perspective, whether or not it's enough weight loss to be clinically meaningful, I think those are all important questions. And whether or not that that actually effort feels effortful anymore in terms of have they been able to kind of engage in habits and work- Those lifestyle changes into their overall lifestyle in a way that they can find sustainable. And that's been like the the key trick is that, you know, every every New Year's,

• 28:35Speaker 01

  people talk about losing weight. And I always say, Well, you know, whatever you're going to do, make sure that you can keep that as part of your life, because otherwise, as soon as you stop doing it, the weight is probably going to increase. And so, yeah, you're right. If people are white knuckling it and saying, you know, I'm just going to do this. And it's a temporary thing, and I'm going to get to my goal weight, and then I can relax. It's like, Yeah, that's not the way it works.

• 28:58Rich Roll?

  We all know how that goes.

• 29:00Speaker 01

  Yeah, right.

• 29:08Rich Roll?

  This is where we're sort of tiptoeing up to the point where your findings are brushing up against a few, you know, pieces of conventional wisdom, one of which is this idea of calories in calories out, right? And for a very long period of time, this was believed to be, you know, basically sacrosanct. Then it was challenged. And now you've you've kind of nuanced it a little bit to bring it back into not Vogue, but like, maybe perhaps it's it's best in proper context.

• 29:40Speaker 01

  Yeah, so I think different people mean different things when they say calories in calories out. And it's helpful to kind of know what are we talking about when we say this? So for example, there are some folks who say, the only thing that matters when it comes to body fat loss, that we have to focus on what is the outcome that we're interested in, is the discrepancy between calorie intake and calorie expenditure. And that's an interesting question. And and it's not necessarily the case that that would be so. In other words, if you could change the type of calories. So the calories we're talking about in food are the calories that you get from oxidizing one of the three macronutrients, or a multiple mixture of macronutrients, carbohydrate fat and protein.

• 30:24Speaker 01

  And it could be that calorie expenditure depends very sensitively on what mixture of nutrients you are provided with, right? And when people were first studying this in dogs back in the 18th, 19th century, what they were doing was very interesting experiments where they were doing all these respiratory measurements in dogs. They were starving them at first to see how much body fat they would lose, and then they'd give them back like sugar. The only thing that the dog gets is sugar. And they'd calculate, how much did body fat loss slow? And they'd give them back fat, pure fat, pure sugar. And it turned out there was very different amounts of fat and sugar that were required to equally slow the loss of fat in a starving dog.

• 31:09Speaker 01

  And this was a mystery for a long time. It's like, why is it you had to give, you know, more than double the amount of sugar to stop fat loss slowing as fat? And it wasn't until this guy named Max Rubner decided to start to think about things in terms of, well, how many calories are in sugar and fat? And so per unit mass, it turns out that the sugar has less than half the calories of fat. And it turned out that the loss of body fat in the dog wasn't matching how many grams of sugar or fat you were giving. It turned out how many calories of sugar or fat that you were giving made the big difference. And the implication was that a calorie is a calorie when it comes to body fat loss.

• 31:53Speaker 01

  But the precision of those measurements was back from the, you know, the 19th century. And it also didn't necessarily follow that the, that it couldn't be that there was some precise combination of carbohydrates and fats that could cause calorie expenditure to vary. And if that happened, then you could still not violate any laws of physics, but you could have it so that, and this is what Atkins claimed, right? He claimed that if you cut carbs enough in the diet, you're, you would have a metabolic advantage, he called it, which was essentially saying that the body was inefficient at running on fat and would have to burn more calories as a result.

• 32:34Speaker 01

  And so you could have a situation where the number of calories that you were eating could be maybe even the same or go up. He called it the high calorie way to stay thin forever, based on anecdotal reports from his patients. Like, I'm not eating any carbs, but I'm eating way more calories than I used to, and I'm still losing all this weight and body fat. Well, the only way to make that make sense is to have calorie expenditure go up. So, again, we think of calories in, calories out as these immutable things that we have total control over. And they're interacting with each other, and they may depend on the macronutrient distributions and things like that. And those are all perfectly legitimate questions to test. And so those were the kinds of studies that we were doing

• 33:17Speaker 01

  for quite some time, was bringing people in to a metabolic ward where they lived with us 24 hours a day, seven days a week. And we would manipulate very precisely how much carbs people were eating, how much fat that they were eating, and measuring with the most precise methods that we had, how many calories were being burned, how much fat oxidation was there, how much carbohydrate oxidation was there, how much was body fat changing, trying to see if what Rubner had suggested back in the 19th century was true in dogs was also true in humans. And we devised the experiment based on some of the mathematical modeling that I had been developing when I first started my career at the NIH. And the first study that we did was actually designed in a kind of an interesting way

• 34:02Speaker 01

  because we thought that we could show that Rubner, while maybe close to being right, it doesn't have to be perfect, right? That there could be a situation where you could see a discrepancy. And so we designed this study to test that. And in fact, we did see a discrepancy, clinically meaningless discrepancy, by the way. It's like, absolutely, it doesn't make a bit of difference when it comes to practical considerations for losing body fat. But we saw a discrepancy such that when the same people with obesity had a 30% restriction in calories coming only from fat, versus in another time, the same folks only from carbs, when they reduced the amount of calories coming in from body fat, they lost a tiny bit more body fat than they did when the same people had the same number of calories

• 34:46Speaker 01

  restricted from carbs. Suggesting that a calorie wasn't exactly a calorie, but the difference was so miniscule that clinically, it's totally meaningless. But, you know...

• 34:59Speaker 01

  As a background in theoretical physics, I think that even these kind of

• 35:02Rich Roll?

  Any, yeah, if that is like a hard and fast principle, any deviation at all is worthy of investigation.

• 35:09Speaker 01

  Exactly. And so that's why I was excited by that result, right? And, and kind of shocked when I saw like these competing diet tribes take that same study and say, oh, it's either completely flawed and worthless and it wasn't low carb enough or whatever. And then another group were pro low fat. So it's like, finally, you've proved what we've suggested all along.

• 35:28Rich Roll?

  Well, this is, yeah, I mean, this is rampant in every tribe, in every diet cult.

• 35:34Speaker 01

  But the point is, is that the physiology is incredibly complicated. And even how the body achieves this near equivalence, and even though it's not precisely equivalent, is incredible, right? Inside the body, it's like the hormonal system stands on its head in order to manipulate what, what the different fuels are shuttling between the different organs, how hormones are changing, just to make it so that it's approximately true that when it comes to body fat changing, something that Rubner had no idea about. It was a black box for his dog experiments. He didn't know about insulin. He didn't know what the liver was doing, what the muscles were doing, what the pancreas was doing. No clue about the inner workings of the physiology. But it's just so fascinating that the implications

• 36:16Speaker 01

  of this is that we can survive as humans or dogs on a wide variety of macronutrient distributions. And when it comes to storing or mobilizing calories from our body fat, the professional, you know, organ that is there to store calories, it's more or less equivalent. And it doesn't have to be perfect.

• 36:36Rich Roll?

  The human animal is, is highly adaptive and resourceful. You know, what I take from what you just shared is essentially, everything is more complicated than you think it is. Yes, calorie in, calorie out, sure, but more nuanced than that. You know, the carbohydrate insulin model or, you know, the hormonal kind of view of this whole thing. True, but also more complicated than perhaps we imagine. And then I think on top of that, there's the added layer of complexity, which is that the scientific method, you know, by its very nature is reductionist and You know, to apply a nutritionally reductionist approach to all of this is flawed in and of itself because just macronutrient ratios aren't telling the whole story.

• 37:20Rich Roll?

  Like, you have to contextualize it in the holistic food, like the food matrix itself. Like, how much fiber is in this and what does fiber do to the uptake of calories, et cetera? And this is, you know, like, it just gets super murky from there. And then perhaps, you know, I'm interested in like, can you draw conclusions from all of this, given like, the vast complexity of all of it?

• 37:43Speaker 01

  I mean, it's incredibly hard, right? And I think that that's, as scientists, we have to be really humble in kind of saying what we think we know about the system and what things do we have a certain amount of confidence in and what things are just really beginning to be understood. And I want to take you back to, it's not just the nutritional complexity of food, but it's the food environment that we find ourselves in, right? So, kind of going back to the comment about these different feedback loops that we talked about that are preventing us from losing more weight than we would like and the effort that's involved in keeping weight off in a given environment. Well, the funny thing is that, and we're only beginning to understand this, you take

• 38:24Speaker 01

  that same person and you shift them to a different food environment. What was effortful before is no longer effortful. In other words, whatever points that were regulating our body weight and our appetite and our energy expenditure, those controls that are helping us regulate body weight turns out to be incredibly influenced by the food environment that we find ourselves in. So, you know, I was doing these studies where we were manipulating macronutrients and observing these little tiny clinically meaningless differences, but as soon as we started to do experiments where we basically said, "Look, eat however much you'd like, we're just going to change the foods that you're exposed to." Now we're starting to see hundreds of calories a day differences.

• 39:08Speaker 01

  And when these people are being told, "Eat as much as you'd like, don't be trying to change your weight, we're measuring lots of stuff, what you don't know is we're measuring all your leftovers." And we're going to calculate how many calories you decided to eat in these different food environments. And they're really short-term studies, lots of limitations, very artificial food environments. But the point is, is that the environment is somehow interacting with our fundamental biology in ways that we still don't fully understand, and is making it so that whatever point we're regulating, or whatever narrow range of body weights that we're regulating, is so influenced by the food environment. And the neuroscience of that is only beginning to get unpacked. It's a really fascinating

• 39:51Speaker 01

  sort of observation that despite people not trying to change the numbers of calories that they're eating, and trying to change their body weight, they're spontaneously changing them by hundreds of calories per day, spontaneously gaining weight, gaining body fat, losing weight, losing body fat, without any effort whatsoever. And I think that's incredibly fascinating. And it's also suggests that maybe that's what we're seeing in society writ large when it comes to the increasing amounts of average body weight and the increasing prevalence of obesity that we're seeing, is that something about our food environment has changed. And the science of that is, I think, still beginning to get unraveled.

• 40:30Rich Roll?

  It's the environment, stupid. You know what I mean? It's like, we can, we can argue about the food pyramid, or the food plate, and like, all this sort of stuff. But fundamentally, it is, you know, you're going to eat what is in your environment. And if there is a core kind of theme or thesis to all of your work, it's that, you know, this obesity epidemic, this incredibly precipitous rise in chronic lifestyle ailments are primarily the result of toxic food systems. It's a systemic issue. And all of this focus on willpower, or the failure of willpower, and individual food choices, has to be contextualized within that, in order to really understand what's going on, and craft solutions that are going to be effective.

• 41:15Speaker 01

  Right, yeah, I think that that's right. And the degree to which some individuals might have a lot of success, even within a given food environment, some of it is by limiting the foods that they're exposed to, or limiting the foods that are on their list of things that they are even deeming possibly acceptable. So I sort of view that as a pseudo sort of local environment shift in that way. And the folks who have, you know, the privilege and the interest and the energy and the motivation to kind of engage in that sort of local environment shift and have access to the kinds of foods that are likely to drive the body weight regulatory system in the positive direction, yeah, clearly they're going to have the most success.

• 42:00Speaker 01

  And there's lots of roles and lots of good reasons to kind of engage in those with those folks on an individual by individual level. And there's lots of people whose careers are made on that sort of thing, and I completely encourage that. But I think it overlooks the fact that, you know, body size in a given environment is, you know, 40 to 70% heritable. And that some of us are more genetically susceptible to shifts in our food environment than others. And at the population level, what we have to account for is the full complexity of that food environment. So it's not just the foods themselves, it's the context and how they're advertised, what are the most inexpensive, the most convenient, the most readily available foods, you know,

• 42:44Speaker 01

  what are our skill sets, how are we relating to our, in our social situations, do we have supportive folks who are going to support us to make changes in our local environment, or are they going to resist those changes? It gets incredibly complicated. But at the broadest possible level, it just seems like the most obvious explanation for what we've seen happening, the shifts in the body size distribution. I mean, they happened, they started happening, you know, centuries ago, in positive ways, right? We saw increasing weight and increasing height, where as a result of nutritional deficiencies, right? Something shifted as we kind of got into the middle of the 20th century. And that's, you know, where we get Into the major shifts in the industrialized food system and why not.

• 43:28Rich Roll?

  So I love the fact that you're you're very kind of anti diet tribalism like, you know, listen, you can be healthy and sustain weight loss on a low carb diet, on a high carb diet. Like, we can quibble around the edges there and people can fight and go to loggerheads over all that kind of stuff. But fundamentally, the the 800 pound gorilla in the room is ultra processed food. So when we're talking about food environments, I mean, that is that kind of lurking giant that's driving all of these deleterious health outcomes.

• 43:58Speaker 01

  Yeah, I mean, the way I sort of see it is even taking one step back, which is, you know, ultra processed foods are the consequence of what we call in the book, the calorie glut. So ever since the introduction of agriculture, humans have struggled to provide enough calories to feed populations. That was in the kind of devil's bargain that was struck when we moved into agricultural systems is society populations could grow less and less people were responsible for producing food and we got civilizations and whatnot. But at the same time, we were always threatened with population growth exceeding the ability of agriculture

• 44:39Speaker 01

  to feed populations. And there's obviously periods of mass starvation. Thomas Malthus, kind of a very famous 18th century thinker, basically made this observation that we're basically doomed to starvation because agricultural productivity and yields cannot possibly keep pace with what he saw as exponential growing populations. We bucked that trend for the most part.

• 45:05Rich Roll?

  Yeah, I think we have pretty much.

• 45:07Speaker 01

  But it's interesting.

• 45:08Rich Roll?

  It's crafty, you know.

• 45:09Speaker 01

  It's amazing.

• 45:10Rich Roll?

  It's kind of ingenious, the solutions that humans came up with to solve this.

• 45:14Speaker 01

  It is amazing. And we think that, okay, yeah, that's 18th century Thomas Malthus. It was, you know, biologist Paul Ehrlich, even in the 1980s, was still saying that we would have mass starvation in America, right around the same time we were exceeding, seeing an explosion of obesity prevalence. And

• 45:34Speaker 01

  You know, it's amazing what we've been able to do with agricultural yields and industrialization of farming and whatnot, but we basically put in place in the middle part of the 20th century, all of the resources and research to maximize calorie production, especially in places like the US and Canada and Europe. We did a calculation for the book, which I thought was kind of interesting. If you just take the four commodity crops for food, rice, corn, wheat and soy, and you ask the question, how many calories per person, per day are produced in those few commodity crops? Turns out to be 15,000 calories per person per day.

• 46:17Rich Roll?

  Wow.

• 46:18Speaker 01

  So sixfold what the nutritional needs are. And we've been finding ways to kind of get rid of that glut of calories, right? A huge chunk of the soy and the corn goes to biofuel production, right? Which for many-

• 46:31Rich Roll?

  And animal agriculture.

• 46:32Speaker 01

  And then animal agriculture is the other big chunk of it, right? And the reason why that sort of works to get rid of it is because, well, animals have a metabolism, right? They don't just kind of translate one calorie of corn into one calorie of meat, right? They waste a lot of those calories by living, essentially. And so it's a very inefficient process, animal agriculture. And so, yeah, so at the end of the day, you end up with something more like 4,000 calories per person per day in the actual food supply of America. And even that increase since the 1970s is more than enough to explain obesity. Turns out that about two-thirds of the increase in calories in the food supply, after accounting

• 47:15Speaker 01

  for animal agriculture and the exports and the biofuel production, two-thirds of that increase went in the trash.

• 47:22Rich Roll?

  Yeah, you have this interesting correlation between the increase in food waste and the increase in obesity.

• 47:30Speaker 01

  Yeah, and I don't think it's an accident. I mean, I think that the point is that we have produced this calorie glut and come up with very clever ways of offloading it, both in terms of animal agriculture and biofuel production, and the other part is ultra-processed foods, right? Taking those cheap- High-yield inputs to the food system and coming up with incredible ways to transform them. Who would have thought you could take corn and make basically sugar, high fructose corn syrup for use in products?

• 48:01Rich Roll?

  Subsidizing it to artificially deflate the price of it, to make it widely affordable, hyper-palatable, highly caloric, nutritionally deficient, and also something about it that makes us want to eat it quickly.

• 48:15Speaker 01

  There's that too, right.

• 48:17Rich Roll?

  So that we're ahead of our sort of appetite suppressant impulse.

• 48:22Speaker 01

  Right. And I think that there's, you know, a lot of people say that, you know, the food industry knows all the mechanisms by which these things cause us to overeat. I don't necessarily think that's true. I mean, I'm sure that they're trying to come up with incredibly tasty products that do well in the marketplace, right? And when they fail, and many of them do fail, they basically re-engineer a replacement and put it back. It's like evolution, right? It's like selection of the fittest products in the marketplace that are maximizing sales, right?

• 48:52Rich Roll?

  What happens if you put Fritos in a Taco Bell burrito? Do people like that?

• 48:56Speaker 01

  Exactly. It's like, let's try it out. You know, we got a little focus group, they said they liked it enough to, let's try it out. And yeah, that's the food environment that we're experiencing right now. And I think the point is, both in the agricultural sector, all along the path, we have these externalities that are not part of the equation, right? All of the environmental damage that was done to kind of do this industrial agriculture, all of the problems with the animal agriculture, just from a moral perspective, as well as, you know, the manure that's produced and the methane that's produced and climate change and...

• 49:34Rich Roll?

  And the depletion of the soil. So the nutrients that end up in the food are less than they once were.

• 49:41Speaker 01

  Yeah, I mean, there's some debate. There's some debate about that, I think, about how important that is, but I think that there are certainly cases where that's been shown. The other big externality has been healthcare costs, right? I mean, the fact that we are experiencing this dramatic increase in diet-related chronic disease that is essentially bankrupting Medicare, Medicaid, and the health sector. And to think that this entire process of solving Malthus', which is essentially we've solved Malthus's problem, right? And we have to do something to kind of change this, not just for the health crisis, but the fact that we're going to have 10 billion people on the planet in not-too-far distant

• 50:26Speaker 01

  future. That solves Malthus's problem because the population is no longer expected to increase. What do we have to do to the food system to both ensure that we have equitable distribution of calories and that those calories are actually healthy for us and the planet? That's the grand challenge of agriculture and nutrition and food science for the next several decades. And we need to think about it in this context. In some sense, like, the obesity and diet-related chronic diseases are like the epiphenomenon, right? They're the thing that happened because we front-loaded all those calories in the agricultural system, and now we've got to figure out a way to steer past that. Fortunately, we have some therapies that are entering the market that can help the

• 51:09Speaker 01

  folks who are most genetically susceptible to those changes in the food environment. But we've got to think past that as well and look to see, where do we want to end up when we have to feed 10 billion people a healthy diet that's equitably distributed as well as sustainable for the planet?

• 51:32Rich Roll?

  I mean, here's where everything bifurcates, because on the one hand, we have personal choice: what are we deciding to put in our mouths a couple times a day? What's available to us and affordable? What is the extent of our personal agency and our relationship with our own bodies? And then there's public policy, and what's good for the whole, and what are the systemic changes that we need to make for a healthy planet and a healthy populace, all of that. And those are... Two sort of different discussions. I mean, they inform each other. But I think in the conversation around, you know, well-being and addressing the obesity epidemic, these two things get conflated and confused with each other.

• 52:15Rich Roll?

  And perhaps this is where you kind of butt up against HHS here a little bit, because there's such a palatable irony here. Because you're raising the alarm of ultra-processed foods. Like, this is really what's driving all of the problems, which is in parallel with everything that RFK Jr. is saying and what the whole Maha movement is about, right? So you would think, hey, you know, you're an ally to this movement. But your research didn't exactly line up with whatever RFK decided was the truth, and this is where this conflict arose. Can you talk a little bit about that?

• 52:51Speaker 01

  Yeah, sure. I mean, let's go back even before the last election, right? So before the last presidential election, this was a bipartisan issue, right? And we can go way back when it wasn't a bipartisan issue with Michelle Obama and the Let's Move campaign. It was clearly a Democratic issue, and people were interested in improving our food and addressing obesity. That was clearly a-

• 53:17Rich Roll?

  Yeah, and that didn't go so well.

• 53:19Speaker 01

  Did not go well, right? And for all its good intentions and whatnot, it did not go well. But there was something different that was going on. I think a lot of it had to do with the discussion about ultra-processed foods, because we've had these discussions back, you know, it's either been sugar, or saturated fat, or sodium and salt, that have all been like public health enemies. And they've all had, there's a lot of data behind those kinds of campaigns and why it would be better for people to eat less salt and eat less saturated fat and eat less sugar and things like that. And I don't think there's many folks who disagree with it. But they didn't really capture enough public attention, especially at the political level,

• 53:59Speaker 01

  that, you know, I don't remember seeing a Senate hearing about, you know, added sugar, right?

• 54:05Rich Roll?

  Well, it was interpreted at that time, and perhaps that was a failure of the message. As an affront to personal liberty, like the government's going to tell you what you should eat.

• 54:14Speaker 01

  Right, right.

• 54:14Rich Roll?

  And like, how dare they, you know, kind of intrude upon my personal choice.

• 54:18Speaker 01

  Right, right.

• 54:19Rich Roll?

  As opposed to, hey, there are shadowy, you know, giant corporations who don't have your best interest at heart here, and they're out to get you. Or, you know, there could have been a different way of communicating that message at that time.

• 54:32Speaker 01

  And I think possibly that's part of what this idea of ultra-processed food has kind of brought to the table, has been the fact that all of these things are important about the nutrient properties of the foods that there are, and the way that they're marketed, and the overall system of food that we're experiencing, and how it's changed since, you know, the middle of the 20th century. And so, yeah, we had like, you know, Bernie Sanders, Cory Booker, you couldn't tell their comments about this from Bill Cassidy or RFK Jr. at the time. It was like, it was, and I still think that if you talked to Cory Booker today, he would probably tell you, well, he's on honeymoon, I guess, right now.

• 55:10Rich Roll?

  Yeah, he's on a honeymoon right now. But no, but this is, this is an issue that he cares deeply about.

• 55:14Speaker 01

  Exactly.

• 55:15Rich Roll?

  And has been working on for a very long time.

• 55:17Speaker 01

  Exactly. And so I still think that for this particular set of topics, there is bipartisan support. And before, you know, this current administration, nutrition science has been funded horribly by the NIH for a very long period.

• 55:31Rich Roll?

  So it's not a new situation that the funding has been anemic.

• 55:35Speaker 01

  Exactly. And we've been focused, I think, you know, this is a good justification for doing this, but there's been a huge focus on the sort of biomedical program of let's figure out how to treat and cure disease, right? No one's going to argue with that, right? Everyone wants to be able to cure cancer and treat diabetes with better, you know, therapies and whatnot. But there has been less emphasis and less funding on nutrition science and prevention, and the environmental drivers of disease prevalence.

• 56:05Rich Roll?

  Because?

• 56:07Speaker 01

  It's a great question.

• 56:08Rich Roll?

  Is it, you know, is it big food lobby money that is influencing appropriations?

• 56:15Speaker 01

  I don't know. I honestly don't know.

• 56:17Rich Roll?

  Lack of political will?

• 56:18Speaker 01

  I mean, I would say that there's probably, let's, let's face it, when do people get exercised about, you know, disease? It's when they get a disease or a loved one gets a disease, right? And the first thing they want is a cure. So there's a huge amounts of lobbying from organizations and people who have already suffered the consequences of diseases that were put in motion by environmental drivers a long time ago. And the ask is not, let's fix those other things that have driven this for, you know, my grandchildren. The ask is, I want to know what it is that I'm going to have to do to get a cure in the few years left that my, you know, parents or my child has this disease. That's a very

• 57:03Speaker 01

  powerful message that, that resonates with people. And I don't, I don't want to take any, anything away from that.

• 57:10Rich Roll?

  Sure, the acute nature of it. But, but, but, but far more people are walking around thinking, how come I'm getting fat? And how come I can't lose weight? Like, I mean, that is just, you know, that's, that's like, you're capturing like 80% of the population or probably more.

• 57:24Speaker 01

  And to be fair, we've come up with pretty decent treatments in recent years for several of those things. And I, and I think that that's a good thing for those things. But it doesn't mean-

• 57:33Rich Roll?

  They're not root cause solutions.

• 57:35Speaker 01

  They are not root cause solutions. That's, that's correct. They are solutions for some people, and I don't think we should minimize that. And like I said, they are part of the bridge that's going to get us to what we need, where we need to go with our food system.

• 57:47Rich Roll?

  By this, you mean like bariatric surgery or GLP-1s?

• 57:50Speaker 01

  Yeah, exactly. Like, these are treatments for the ones, the folks who were most genetically susceptible to the environmental changes that have put in place the increase in obesity prevalence and the downstream consequences of that. We thankfully now have effective treatments, and some of them can scale at a level that, that will help many of those people. I think that's a great thing. But I think you're right to point out that funding to figure out what are, how are we going to move past this? And what was the cause of these problems in the first place? It's been underfunded and nutrition science in particular has been underfunded. And I think it's tragic and you know, I experienced that even in the last administration.

• 58:33Speaker 01

  What we've, what we've, after we had this big paper on ultra-processed foods come out showing that when people are exposed to environments with lots of ultra-processed foods, they ate many, many more calories, they spontaneously gained weight and gained body fat.

• 58:45Rich Roll?

  Shocking, without a doubt. That was the result.

• 58:47Speaker 01

  And then shifting them to a minimally processed environment, again, these environments were matched for the number of calories that were presented to people, the macronutrients, the glycemic load and the fiber and the sodium and yet.

• 59:01Rich Roll?

  And the nutritional dark matter, which we haven't even talked about.

• 59:04Speaker 01

  Which we haven't even talked about. So that they've experienced this change in their food environment spontaneously, just I just decided to eat less, I'm not trying to do anything, just effortless shifts. After that study came out and garnered like way more attention than I thought it was going to get, they want to close down the unit at the NIH.

• 59:25Rich Roll?

  And this was prior to 2020, this is before the Trump administration.

• 59:30Speaker 01

  This is 2019.

• 59:31Rich Roll?

  Okay, yeah, yeah, yeah.

• 59:32Speaker 01

  So the same year that that paper came out, we were told by the CEO of the clinical center that they were going to close down the metabolic unit. I remember sitting in a, in a room and afterwards I said, you know, I, I just, I don't see how I can have any confidence that I can continue to do our studies if, if this unit's closed. And he said, yeah, you shouldn't have any confidence that you can continue your studies.

• 59:55Rich Roll?

  And what is your, what is your theory of mind there? I mean, what, what is the, the motivating?

• 1:00:01Speaker 01

  The motivating fact was that, you know, I think he had plans for that facility that he thought were better suited and we can have a debate about that. And he was in a higher position at the NIH than I was. And yeah, I think that there are several theories. I think he wanted to maybe set up an Alzheimer's unit. I'm not exactly sure what the different competing theories were, but we could have a debate about that, but that was, the debate was sort of shut down. I ended up finding out someone at a higher level at HHS who had read our paper and I said, hey, I heard you. Read our paper and we're intrigued by it's too bad we won't be able to figure out what the mechanisms were because the unit's gonna get close.

• 1:00:39Rich Roll?

  It's outrageous to me because like our entire epidemic of chronic lifestyle illness all tracked back to this, right? And not only is this driving all of these incredibly poor health outcomes and debilitating millions of people unnecessarily, it's at the root of what's ailing our healthcare system. And it's so, from an economic perspective, which then becomes a national security issue, like these are gigantic problems that need to get solved that are important for the sanctity of our democratic union fundamentally. Like it's more than just people are getting sick. Like this is why healthcare is so expensive

• 1:01:23Rich Roll?

  and so bureaucratic and so kind of overwrought right now. And we have to solve it if we want to figure out healthcare.

• 1:01:31Speaker 01

  I completely agree. And so while we were successful at pushing back against that attempt at closing our unit. So that's why in the run up to this last election with the attention that this was receiving on both sides of the aisle, I was super excited, right? I thought.

• 1:01:47Rich Roll?

  Because here comes a guy and he's talking about this stuff that I'm studying and that I care about. But prior to that, before we even get there on the timeline though, is it true that you almost got fired for writing this book? Like this is before the current administration, right?

• 1:02:03Speaker 01

  That is true also.

• 1:02:04Rich Roll?

  What?

• 1:02:06Speaker 01

  Yeah.

• 1:02:06Rich Roll?

  Like you're just a guy at NIH doing research on processed foods and metabolism.

• 1:02:10Speaker 01

  Yeah, that's true.

• 1:02:12Rich Roll?

  What's the big threat?

• 1:02:13Speaker 01

  Well, I think there's a couple of things, right? And it was expressed to me that two main concerns. One was that we have an entire chapter about policy.

• 1:02:23Speaker 01

  The NIH has always sort of prided itself as we provide the science, we don't opine about policy.

• 1:02:30Rich Roll?

  We don't make policy decisions.

• 1:02:31Speaker 01

  Right, we don't want to get involved in policy decisions. And the second thing that they pointed out was that, the other thing we point out is, in the book, there's a lot of, I wouldn't say it's debunking, but it's a lot of challenging of claims that various folks are making in different spaces, like the different diet communities, the different folks who are selling supplements, who are selling precision nutrition programs, and they didn't want pushback from these folks.

• 1:03:01Rich Roll?

  I see, and because you're a government employee, it's creating a headache for them.

• 1:03:06Speaker 01

  Yeah, so I initially said, look, what if I just kind of, you know, not put my affiliation on there, and there was, they didn't agree to that, and they said, no, if you're an author of the book, you're going to be disciplined and likely removed from your position. And so I actually had to hire a lawyer who is well-known for, he's well-known for basically representing clients who write books after they leave the national security space. And he's like, are you trying to like, reveal some classified information? I'm like, no, and he's like, I don't understand, this is the most bizarre thing you'd ever seen. Anyway, he was able to kind of, basically, get the NIH to assent to letting me be a co-author of this book, and, and by the way, this-

• 1:03:51Rich Roll?

  And keep your job.

• 1:03:52Speaker 01

  Keep my job, right, which I've since left, which is, which is the other part of the story, right? So, so yeah, so I guess the point was, is that, you know, after that was resolved, and I thought I would be continuing with the NIH, and this new administration was coming in, and that there was bipartisan support for finally kind of investing in, in understanding what's going on, and tackling these issues of diet-related chronic disease and ultra-processed foods, you know, I was very excited about this. And in fact, I started working with the director of the NIH Office for Nutrition Research about, you know, we've been doing art studies, which are pretty small scale, they take years to complete- Because we can only house two or three people at a time.

• 1:04:37Speaker 01

  What if we had facilities for other researchers where we could house people for more comfortably, not in a hospital, and keep dozens of people at a time? Get answers to these questions that the American people deserve in a matter of months rather than years, and we could cycle through different hypotheses and different mechanisms that we were studying. And we started to work on a plan of how we would do this. And I was trying to contact members of the Maha kind of leadership to talk about this, but they were too busy talking to social media influencers at the time. But, you know, we were plugging along, doing our work. Eventually, I wanted to be able to kind of present this sort of plan to folks.

• 1:05:19Speaker 01

  And, you know, in that transition period, after the new administration took over, we started to see that certain topics were deemed sufficiently politically interesting that any sort of work that would be, you know, communicating results, going to conferences, any new programs had to kind of go up to the level of the Department of Health and Human Services and be approved by a political appointee. And so I started to experience this directly. The first occasion was I was supposed to give a talk at the Bloomberg Philanthropies Annual Meeting about some of our work on ultra-processed foods.

• 1:06:03Speaker 01

  And, you know, for the first time in, at that time, 21 years at the NIH, I was denied the opportunity to give a talk at the conference. Now, it was unclear exactly at the time, was this because of travel restrictions? And so I went back to the Bloomberg folks and said, could I do this remotely? Would you mind if... They're like, yeah, no problem. So I requested the ability to do this. Still denied. And this was at a time when my colleagues were being allowed to give talks, especially remote talks. So there was something special about the results that we were trying to present that was being, you know, suppressed in this way. We were interested in the question, do, does ingestion of ultra-processed foods hijack

• 1:06:48Speaker 01

  the brain's reward system in the same way that cocaine does? I guess the question is, addiction doesn't necessarily have to occur through this particular biological pathway. Okay? Yes, this has been a common phenomenon in that drugs like cocaine and methamphetamine, even nicotine, cause an outsized surge in dopamine in the brain, which leads to a bunch of adaptations that can lead to addiction. There's a very long history, even in the obesity space, of looking at neuroimaging studies of the brains and dopamine receptors in people with obesity and people who are lean and saying, hey, look, the brains of people with obesity look more like people who've been addicted to cocaine than the folks who are lean.

• 1:07:32Speaker 01

  And so there is this particular neurobiological mechanism of addiction, which is well-understood with cocaine, but it's always been hypothetical when it comes to food addiction. And so that's the reason you do research in this area. Right, so let's look at it and figure out if that's truly the case. Exactly. And so what we found in this study, it was a very large study, the largest study of its kind, and it was designed to assess the question of whether or not people with obesity have the same sort of adaptations that, in dopamine receptors, that you see in people who are addicted to drugs over the long term, implying that people with obesity might be more likely to have food addiction.

• 1:08:10Speaker 01

  And, secondly, whether or not they see this outsized dopamine response, similar to cocaine ingestion, and is that different between lean and obese people? And we did not see that latter effect. And so we wrote this paper, and the paper was written and submitted before the administration came in, it was accepted for publication, and we were starting to want to talk about it at conferences. And so you're right that... It was perceived, I believe, by folks at political level at HHS as saying, I don't need to think about it. I know that they called a reporter from the New York Times,

• 1:08:51Speaker 01

  the communications director, and said, the results of this paper don't match RFK Junior's thoughts about ultra-processed foods.

• 1:08:59Rich Roll?

  It was politically inconvenient, and so they interfered with your ability to have a press release and to speak to the New York Times about this.

• 1:09:07Speaker 01

  Correct. And they edited my answers to the reporter's questions.

• 1:09:11Rich Roll?

  They provided written responses where they editorialized what you had to say, without giving you the opportunity to...

• 1:09:16Speaker 01

  Well, no, actually, actually saying that I wrote it.

• 1:09:19Rich Roll?

  Oh, really?

• 1:09:20Speaker 01

  Yes. It was a tribute to be...

• 1:09:22Rich Roll?

  It was provided to them in your words. Were you able to get a correction from the New York Times out of that?

• 1:09:27Speaker 01

  No, I was in communication with the reporter for the New York Times, so I just made sure that she quoted only from the sections that I had written, not the embellished sections that downplayed the study. So, yeah, this was like direct interference with the ability to communicate these results. And so, at the time, they're trying to get as many people to leave the NIH as possible, and they put up this early retirement option several weeks later. And so, after experience...

• 1:09:54Rich Roll?

  This was like in the middle of Doge.

• 1:09:56Speaker 01

  Yeah, yeah, exactly. And, you know, we had ongoing studies, and, you know, again, I wanted to kind of talk about the plans for what we, how could we improve the situation? I'm completely aligned with the, you know, the goal to make America healthy again, that ultra-processed foods, we need to better understand how they might work and what the mechanisms are. And so, I wrote, I wrote to RFK Junior, his senior staff, I wrote to the NIH director, and, and said, look, here's what I've experienced. At that time, we actually also weren't able to buy food for our research participants. We couldn't buy research supplies. We weren't able to rehire people who were leaving on a regular basis that run our studies.

• 1:10:41Speaker 01

  It was like a very bleak time. Fortunately, some of those things have turned around a little bit at the NIH. They're still experiencing some of these difficulties, purchasing research supplies, for example, still to this day. But we were experiencing really acute problems. And so, I was, and I've been talking with our scientific leadership, like, what's, what's gonna happen here? Right around that time, it had leaked that there's gonna be a 40% cut to the NIH budget, and very dire time. So, I wrote to these folks and said, look... Not only are we experiencing these problems, but you know, we're totally aligned and we can make a lot of progress. In fact, I told them about this ongoing studies, how we're making progress, understanding mechanisms of ultra-processed foods. Why do they make people overeat?

• 1:11:26Speaker 01

  That we'd been able to redesign an ultra-processed diet that was still 80% of calories from ultra-processed foods that didn't actually cause people to overeat by focusing on mechanisms, that we could do a lot more in the future. If we kind of engaged in this plan and I sent them the copy of the plan, you know, actually requested a meeting. And I basically said, otherwise, I can't see how we can continue research in this space and you know, I'm going to prepare to retire through this program. And so I didn't hear anything as a result of that, except a colleague of mine said, hey, are you really going to retire? And I'm like, possibly, how do you know?

• 1:12:07Speaker 01

  And he said, well, this, your email was circulated among senior staff at NIH. And so someone read it, but nobody reached back out to me. So I spent the next weeks kind of reassigning staff and reassigning my clinical protocols and closing down a 20-year career at the NIH, because I didn't see a way to kind of move forward if we're going to be interfered with in this process and that there was no interest in engaging in this topic. At the same time that they're holding, you know, meetings with folks drinking raw milk in the White House.

• 1:12:44Rich Roll?

  I mean, it's just unfortunate because you know, there is a lot of energy around ultra-processed foods and what's happening there. And you know, he's, you know, very much a flashpoint in drawing attention to this. And you know, and that's a good thing writ large. And you could have been this ally, like you're the guy who's looking at this more closely than anybody else. Like it's confusing why there couldn't, you know, be some kind of consensus about how to move forward together on this.

• 1:13:12Speaker 01

  Yeah, and even more disappointing. And I think one of the things that solidified why I think I made the right decision, because obviously. I agree with you, and I think that, you know, we could have made a lot of progress. You know, after I left and it made a little bit of, you know, press coverage.

• 1:13:28Rich Roll?

  Yeah, there was actually a lot.

• 1:13:30Speaker 01

  Yeah, there was.

• 1:13:31Rich Roll?

  You were, that must have been strange for you.

• 1:13:33Speaker 01

  It was a little strange.

• 1:13:35Rich Roll?

  You know, a scientist at NIH, suddenly, you know, Jake Tapper is talking about you and you're just kind of everywhere.

• 1:13:40Speaker 01

  Well, the interesting thing about the, so the day that I talked with Jake Tapper, earlier that morning, I met with the NIH director, the new NIH director.

• 1:13:49Rich Roll?

  Jay Bhattacharya.

• 1:13:50Speaker 01

  Jay Bhattacharya, yeah. So he saw the New York Times article that came out, like, I think, the day or two before that. And he said he wanted to meet with me. And so I went back to the NIH. And he wanted to know what happened. And I was there with him and the deputy director for intramural research. Intramural research is the part of the NIH that does their own studies. Extramural is the granting part of the NIH. So this was basically my boss's boss's boss. And the NIH director. And, you know, he was interested in the censorship thing because he feels like he was censored during COVID. And it was clear he could probably have talked the entire meeting about that. But I tried to transition and he told me he had not seen my email and I believed him.

• 1:14:33Speaker 01

  I mean, he was new to the job. Somebody probably saw it in his staff. But I believed him when he said he hadn't seen my email. And what I wanted to focus attention on was, what about this plan? Like, you know, the purpose of my email was, yeah, I wanted to tell you about the troubles that we were experiencing in the censorship and whatnot. But the main part was, could we get on the same page and actually improve the science to investigate this, to give the, you know, get the answers that the American people deserve. And you're right, there is so much passion about this issue right now. And it had been clear that he saw, you know, the email that I wrote and he'd saw the plan.

• 1:15:15Speaker 01

  And he said, yeah, I'd really like to work with you on this. And he shook my hand and he said, welcome back. And I said, well, I'm not back yet. I've got nothing to go back to, right? My lab has been closed. My staff has been reassigned. My protocols are being run by other investigators, but I'd be really interested in working on this with you. And he said, okay, we'll talk to Nina and we'll figure something out. And, and I got back in touch with the, the director of the Office of Human Nutrition Research and we continued to work on this program. He presented it again at the NIH. We were talking about funding for a facility, maybe even located at the USDA Beltsville facility, which was slated to be closed.

• 1:15:59Speaker 01

  They have a big metabolic kitchen and buildings that could be renovated. And I was, I thought I was going back. I was pretty sure.

• 1:16:07Rich Roll?

  The director of the NIH basically said, welcome back. I mean, if he can't hire you back, yeah, it's like, if he can't hire you back, I mean, who, who's going to?

• 1:16:15Speaker 01

  Exactly. So for weeks, you know, I was working with Drew at the Office of Nutrition Research and the intramural, you know, the deputy director for intramural research and kind of putting together this, this plan of what we would do. And then out of, out of the clear blue sky, Drew calls me up one day and he said, I don't know what happened, but it's, it's killed. We're not doing this. He had no explanation. He said, I tried to get an explanation, but I couldn't get one. He said, the closest thing that I can think about is that, you know, this, this personal has to do with you. And I'm like, well, that doesn't make any sense because if they wanted to make it personal, they would do it and then not hire me back, right?

• 1:16:59Speaker 01

  That would be the biggest, you know, way to get back at me. I don't understand what happened, but apparently somebody decided for whatever reason, and still has not been made clear, that, you know, actually investing in this research to better understand, you know, how our diets and our food environments affect diet-related chronic diseases was not.

• 1:17:24Speaker 01

  Sufficient interest to actually fund that research. You know, what I've sort of interpreted this as, and since we've sort of seen other examples of this, is that science only complicates rhetoric. Right? It only introduces complexity and nuance. And when you're trying to make a case for something, especially if you're kind of come at it, and you're a lawyer, you know this, you want to come at it with, you know, the strongest possible case and rhetoric that you can, that you can come at it with. And you want to downplay evidence that might introduce that nuance and suggest it maybe isn't so reliable, and upplay evidence that is really supporting your side.

• 1:18:06Speaker 01

  And doing really good science can only potentially complicate your narrative. And a complicated narrative is more difficult to get action on than a simple narrative. And my view has been that unfortunately, this administration views science as a complicating factor, getting in the way of what they want to achieve as opposed to...

• 1:18:29Rich Roll?

  I mean, the most charitable, that's, that's a very charitable interpretation. The most charitable would be, listen, we really want to solve this problem, but we have to have these reductive talking points, and we can't have anything compromising that because that will distract from the solution. The less charitable interpretation is that you're a political liability.

• 1:18:51Speaker 01

  Yeah.

• 1:18:52Rich Roll?

  Because objectivity is in opposition to the political aims. And when it comes to your solutions, your systemic solutions, they're at cross purposes with the deregulation mandate of the administration outside of HHS.

• 1:19:08Speaker 01

  Yeah, and that's a huge challenge for them, right? Is that there is a presidential executive order that for every new regulation, you have to remove 10 others, right? So how are you going to introduce new regulations on food if you have to remove 10 other ones at the same time? And I think that that's part of the, the other thing, and I know Jessica Nurek talked at length about this, is that the rhetoric doesn't match the actions, right?

• 1:19:32Rich Roll?

  Right. You guys agree on the fact that, that Maha is identifying the problem correctly. It's just that there's, you know, a difference of opinion when it comes to solutions here.

• 1:19:41Speaker 01

  Right, and that I'm a firm believer that science is the best thing that humans have come up with to get closer to the truth, and science-based policies are the best thing that we can have to actually improve the situation. And so, we need to invest in the science in order to improve the situation. And if you don't, if you just think that you have it all figured out, and the history of nutrition and food science has been a repeated, on repeat, as we discuss in the book, people thinking they've got it figured out, and they come up with a very simple sort of narrative, only to be, you know, fall apart when it's subjected to critical tests. And yes, we're making progress, but

• 1:20:25Speaker 01

  very often, those simple narratives fall apart when you subject them to test. I think that the example that we were coming up with was, you know, the dopamine story doesn't seem to be holding up as well as we thought. Doesn't mean that people aren't addicted to food, and ultra-processed foods might be more addictive in other ways, but it definitely complicates the narrative if you can't say, "Yeah, it's exactly like cocaine."

• 1:20:50Rich Roll?

  Well, I appreciate your candor in sharing that story. I'm sorry that that happened to you. I'm sure you'll find, you know, your next thing, and perhaps even reflect back and think, "Well, it's good that this happened, because now I'm here." You're trying to figure that out right now. But I want to shift now to trying to provide people with some actionable guidance while also appreciating the complexity of all of this. I mean, this is gonna, this is gonna publish in a couple of weeks, like, prior to the new year. Everybody's thinking about their New Year's resolutions. I'm sure there's a lot of people watching or listening who are thinking about how they're gonna try to finally lose that extra 10 pounds, or whatever it is. But they're also, you know,

• 1:21:35Rich Roll?

  on the precipice of all kinds of social gatherings where there's gonna be lots, their food environment is gonna be less than ideal. And, you know, what is your counsel to the average person who's trying to navigate their food environment, make better choices, and have a, you know, a better understanding of what's really gonna drive? Sustained weight loss and better health outcomes over the long haul.

• 1:22:01Speaker 01

  Yeah, yeah. So, so I think a couple of points. Well, one is one that I think people, again, too often tie to weight loss, but the effects are especially acutely, but the effects are in, you know, the positive effects are completely independent, and that's exercise. Too often, people around the new year and they kind of come up with some New Year's resolution to join a gym or start an exercise program or hire a personal trainer, and they tie their success to what's happening on the scale. And that's, I think, completely misleading, right? Because even if you don't lose a pound or even gain a pound, if you become regular in your exercise habits, both, you know, your function, your day-to-day function,

• 1:22:43Speaker 01

  your ability to kind of get around and move about in the world, as well as many metabolic consequences, are independent of how much weight you lose. And so I think that's one factor, is that people should not tie their success at exercise with what happens on the scale. And I think that too often we do this, especially in that New Year's time.

• 1:23:03Rich Roll?

  One of the things you talk about in the book and in your work is there is that, you know, not all fat is equal. Like, there is a, there is a distinction between problematic fat and, you know, I guess what you would call like healthier fat. So, just, just the number on the scale or how much like adipose tissue you have doesn't really tell the whole story about your health or lack thereof.

• 1:23:23Speaker 01

  That's right. Yeah, exactly right. And it's the function of your fat, as well as where you're storing excess calories. And if you're storing it outside of your fat tissue, your adipose tissue, if it's in your muscle, for example, or in your liver, then that's the problematic areas. And exercise is potentially beneficial for both of those things, even if the overall adipose tissue doesn't change or changes.

• 1:23:46Rich Roll?

  Visceral fat.

• 1:23:47Speaker 01

  So, yeah, visceral fat is a little bit, it's one of those popular bad guys that people talk about, but I don't think there's really good evidence that visceral fat per se is bad. So visceral fat, again, is adipose tissue. It's a small amount that's around your organs. It's not actually in your organs. And, you know, there's some evidence to suggest that it's really not contributing as much as we originally believed to poor metabolic health.

• 1:24:11Rich Roll?

  Yeah, because I've always thought, oh, well, that's, that's the bad one.

• 1:24:14Speaker 01

  I mean, it's,

• 1:24:14Rich Roll?

  And it's the one you're not, you don't even know if you have it.

• 1:24:18Speaker 01

  Yeah, I mean, and it tracks a little bit more closely with, with liver fat than subcutaneous fat.

• 1:24:25Speaker 01

  It's still a little bit debated about how relevant visceral fat is per se to metabolic health. So for example, if you do bariatric surgery and at the same time you remove visceral fat, you can just take it out, a huge chunk out. And therefore, you don't see the same sort of, people talk about it dumping into the portal vein of the liver and having inflammatory properties, you get rid of that. The meta-analysis suggests you're no better off having your visceral fat removed from a metabolic standpoint than you are from just getting the bariatric surgery. And in fact, if you just, if you cut up subcutaneous fat, you don't get any of the metabolic benefits

• 1:25:06Speaker 01

  of losing weight, right? So there's something special about weight loss per se that doesn't have to do with the surgery, that doesn't have to do with the visceral fat or even subcutaneous fat per se. So it's more likely to be the fat that's in your muscle cells, in your liver cells, or around your pancreas that are the more problematic areas. But the point is, exercise is beneficial metabolically regardless of whether or not you're losing weight, regardless of whether or not you're losing-

• 1:25:35Rich Roll?

  It's such a boring answer.

• 1:25:36Speaker 01

  It is, it is a boring answer.

• 1:25:37Rich Roll?

  Give me the behind the velvet rope, you know, Kevin.

• 1:25:40Speaker 01

  Yeah, yeah.

• 1:25:41Rich Roll?

  It's like, oh, exercise?

• 1:25:43Speaker 01

  Yeah, gee, never heard that before, right? But I think the new part, I don't know how new it is, but the new part is that people, they tie it so closely to weight loss about whether or not they're succeeding.

• 1:25:53Rich Roll?

  Or it's the reason for doing it.

• 1:25:55Speaker 01

  The reason for doing it, right. I mean, the benefits for weight loss don't seem to show up acutely. They show up later. Maintenance of weight loss is pretty closely tied to how physically active you are.

• 1:26:06Rich Roll?

  So it seems like you're saying, don't obsess on weight loss, focus on, you know, eating healthier foods and exercising.

• 1:26:14Speaker 01

  And improving metabolic health, that's right. And you can do that, yes, fat loss can help with that. But, you know, whatever you're gonna do to change your lifestyle or change your, to actually lose weight, you've gotta be- Willing to do that permanently. Because I think, again, that's one of the things that people have this idea that, "Well, I'm going to go on a diet to lose weight in a new year and then..."

• 1:26:38Rich Roll?

  Once you do that, everything's great.

• 1:26:40Speaker 01

  Yeah, exactly.

• 1:26:41Rich Roll?

  You can put your foot off the pedal. I mean, after studying the Biggest Loser contestants and all, I mean, you must have learned quite a few things about the difference between, you know, people who are able to sustain healthy habits and, I mean, this gets into psychology, obviously, but, and those that lapse.

• 1:26:56Speaker 01

  Right, yeah. I mean, so, no, I didn't learn very much.

• 1:27:00Rich Roll?

  You didn't? Some people do and some people don't.

• 1:27:03Speaker 01

  I'm a little bit of a bonehead in that regard. I tend to look at things, you know, if it's not happening in the hypothalamus or the reward regions of the brain. I'm like, that's too much cognitivism. That's a messy psychology.

• 1:27:16Rich Roll?

  You're not from the soft sciences of that.

• 1:27:18Speaker 01

  Yeah. So, yeah, some people might learn a lot, not me. But, um, yeah, I mean, I think it's really interesting, though, because I think that, again, one of the chapters of the book, we talk a lot about sort of precision approaches, like you're the unique snowflake and there's huge variability in the amount of weight loss that people have. And if only we could identify, you know, what special biological properties you have that would promote weight loss in a given intervention. I don't think there's good evidence for that yet. And the presumption seems to be that there's some magic biological driver about who's a success story and who's not. But I think that, again, getting to the softer sciences of this, whether or not you have a supportive partner or a supportive family,

• 1:28:01Speaker 01

  whether or not you have the economic means to kind of make these changes and change your local environment in ways which I think you can. People do have some agency to kind of change those kinds of things. Those are going to be much more important than, you know, signing up for the latest, you know, CGM gut microbiome analysis, which is, in my view, vastly overhyped at the current time and being oversold to people. There's some evidence of that that we present in the book, that, you know, these things are not as reliable as they're being made out to.

• 1:28:37Rich Roll?

  I mean, I think they're tools like anything else. I think they they lack adequate amount of education as a as a sort of, you know, central piece to it. And the technology isn't quite there to provide the best, you know, kind of actionable recourse as a result of these. And I think that the data points, you know, there's so many data points now with all these wearables and it's disorienting and you don't know what's important and what's not. And so you're making health choices based upon short term, you know, data reports that don't necessarily mean anything and can potentially drive, you know, poor decisions around.

• 1:29:13Speaker 01

  That's right.

• 1:29:14Rich Roll?

  Especially with CGMs, like you see these spikes and you think, oh, well, the solution is just not eating anything that's going to spike my insulin. So it's like, all right, well, you can just eat fat all day long.

• 1:29:23Speaker 01

  Right.

• 1:29:23Rich Roll?

  It's probably not great, but you're gonna have a nice line.

• 1:29:25Speaker 01

  Right, right. Yeah, I know. That's right. And I think that the the problem that I have is that the foundational science hasn't been done, right?

• 1:29:33Rich Roll?

  So that the measuring isn't.

• 1:29:35Speaker 01

  We don't, yeah, I mean, so I mean, when one of the studies we did, especially when we have like this complete control over people's environments and in fact, the order of the meals and the timing of the meals, we know all of this about the subjects that we had on, we would basically have one C, two CGMs simultaneous, one on the abdomen, one on the arm, as according to the manufacturer's instructions. And yeah, the results that you get are correlated.

• 1:29:58Rich Roll?

  Wow, very.

• 1:29:59Speaker 01

  But you have this huge variability where the same people simultaneously eating meals, one is rock solid and the other one is causing a spike.

• 1:30:06Rich Roll?

  If they were accurate, within a certain, you know, like reasonable range, would you have a different opinion on that? Because it does seem to me like anything that connects you more deeply with the habits and the choices that you're making and can kind of show you evidentiary proof of like what you're doing and what it's doing to you is probably a good thing.

• 1:30:25Speaker 01

  It can be a good thing if you know how many times you have to measure the thing to have a reliable response. And our data suggests that that's probably more like 10 times, right? Like if you measure the same, similar responses to the same food or same meal 10 times, then you probably have a pretty reliable response. And that's even in the highly controlled situation.

• 1:30:46Rich Roll?

  I mean, that's true of everything. I mean, just as an athlete, like, wearing heart rate monitors.

• 1:30:50Speaker 01

  Yeah.

• 1:30:50Rich Roll?

  Like, I know if I, my chest monitor is always gonna be more accurate than whatever's on my wrist.

• 1:30:54Speaker 01

  Right.

• 1:30:54Rich Roll?

  No matter the sensor.

• 1:30:55Speaker 01

  Mm-hmm.

• 1:30:55Rich Roll?

  But even if all I have is a wrist sensor, I know that, that, that number isn't exactly accurate, but if I do it over time, like, it's more, it's the variability in that number that still provides me with some value.

• 1:31:07Speaker 01

  And I think that knowing that and having done that sort of research in advance is what's lacking in this particular space, right? So, um, and instead, what you get is you get people who see something on just a couple of occasions. You know, they see their, their blood sugar spike eating a banana. And they do it like on two or three occasions and they think, oh, that's what my response to bananas is. And what if that person really loves bananas, right? And it's not really a reliable response, because they haven't done it enough time.

• 1:31:34Rich Roll?

  They're gonna eat bacon instead.

• 1:31:34Speaker 01

  And they eat bacon instead, and you've made their life measurably worse because they don't enjoy the bananas, and potentially, from a health-wise, worse because they're now eating bacon instead of bananas.

• 1:31:43Rich Roll?

  But I think these things, I mean, listen, you know, as human beings, we, we like little shiny bells and whistles.

• 1:31:48Speaker 01

  Of course we do.

• 1:31:48Rich Roll?

  And these things are fun, but, you know, the, the, you're, you're like a pillars guy. And it's like, listen, just stay away from the ultra-processed foods. Try to better control your food environment. You know, when you go to the grocery store, stick to the far aisles where, you know, it's real food. And, you know, exercise and get out, like, all these other things are like, you know, they're, they're like cherry on top of the sundae sort of thing.

• 1:32:09Speaker 01

  They are, and they can be distracting, I guess, is the point. And, and I think the other thing is when it comes to ultra-processed foods is that it is an extremely broad category, right? So that, um, the way it's defined academically.

• 1:32:19Rich Roll?

  How do you draw that distinction? Because I often think, like, okay, so I, I wear a Whoop tracker, right? So, and I love it, and it's great. And, you know, I look at the data points over a broad period of time. Like, I don't get caught up in every single day or whatever, but it has a little diary function. And it's like, and you can, you can choose which little, like, checks things. And it's like, did you eat too late at night? Or, you know, did you eat processed foods? And I'm like, Well, I had some olive oil and I had some, you know, like, is that a processed food? Is that not a processed food? What's the difference between a processed food that you might consider healthy and an ultra-processed food that is just off the table?

• 1:32:57Speaker 01

  And what I'm adding is that not all ultra-processed foods might be off the table either, because it is, even within that category, as defined academically. So there's this NOVA classification system. Basically, it groups foods into four different categories and it has nothing to do with their nutritional properties, which is kind of a lot of the Kirk fuffle about ultra-processed foods is it doesn't talk about, doesn't talk about saturated fat or sugar or sodium or anything like that, or even fiber. But you've basically got whole foods, you can wash them, chop them up, freeze them, all sorts of things. You know, your produce, your even canned produce would be considered a minimally-processed food, as long as it doesn't contain certain preservatives and that are kind of more technologically advanced.

• 1:33:41Speaker 01

  These are the minimally-processed foods. So, eggs, meat, poultry, fish, produce, legumes, rice, those kinds of things. Then you've got processed culinary ingredients. These are the things that I like to think of as you don't eat them on their own. Olive oil, right? No one's guzzling olive oil. This butter.

• 1:34:00Rich Roll?

  I think maybe Stephen Gundry is.

• 1:34:02Speaker 01

  Oh, that's maybe true.

• 1:34:03Rich Roll?

  Anyway, go ahead.

• 1:34:05Speaker 01

  I use the butter example too, but my youngest child actually did eat like half a stick of butter once.

• 1:34:10Rich Roll?

  Don't some of the carnivore people do that?

• 1:34:13Speaker 01

  Maybe they do. Anyway, these are the edge cases. My son and the carnivore people. And, and a sugar would be another example, right? But the point is, is that you are using these so-called processed culinary ingredients to mix with category one minimally-processed foods to create meals or preserve them or enhance their sensory qualities. And in fact, that's the definition of category three, which is called processed food. So breads, pastas, fermented products, these would all be called processed foods. And then, basically, everything else is what's called ultra-processed foods. And so these are typically using a lot of these cheap agricultural inputs,

• 1:34:55Speaker 01

  things that you would not find, ingredients that would not be found in restaurants or home kitchens. They're often using processes and manufacturing methods that are not commonly used. You know, things like extrusion technologies and all sorts of other kinds of things.

• 1:35:12Rich Roll?

  Preservatives.

• 1:35:13Speaker 01

  Preservatives. Also, some categories of preservatives, if they belong to like a kind of a very historical way of preserving, like fermenting is a preservation technique that is kind of belongs in the sort of processed food category. But yeah, other kinds of preservatives, cosmetic additives, flavor additives, those would count as something as ultra-processed. So within that category, all the kind of typical junk food type things, much of the fast food that we have, but also things like whole grain breads that you buy at a supermarket. Things like many of the plant-based meat replacements would be ultra-processed foods. A lot of things like some flavored yogurts and things that many people think are probably beneficial for health.

• 1:35:58Speaker 01

  So it's an incredibly broad category of foods. And the question is, you know, it was an empirical question for a long time. Is our diets high in ultra-processed foods connected, linked with diet-related chronic disease? I think that everybody realizes the answer to that is yes, they are linked. Mechanistically, how that works is still not fully understood. I think a lot of it is probably downstream of obesity, right? Something about this category of foods causes people to overeat calories and gain weight and become, have excess body fat. And as a result, having many of the downstream complications, which kind of overlap with many of the things that ultra-processed foods have been linked to, obesity, type 2 diabetes, cardiovascular disease, several forms of cancer,

• 1:36:43Speaker 01

  and all-cause mortality, in fact.

• 1:36:45Rich Roll?

  At the same time, you would probably also say, like, if you're ultra-processed food of choice is very high in sugar and then you have type 2 diabetes, maybe there's a connection there.

• 1:36:55Speaker 01

  Yeah, yeah, yeah, no, absolutely.

• 1:36:57Rich Roll?

  That extends beyond purely, you know, obesity. Or if you like salty stuff and you have high blood pressure.

• 1:37:02Speaker 01

  Yep, yep, that's true, that's true. So there are independent mechanisms and there's also, I think, one of the strongest areas of independent mechanisms are in gut dysbiosis and gut function and the immune system and inflammation. There's a really interesting study that was conducted by Kevin Wieland on people with Crohn's disease and removing ultra-processed foods and proving symptoms of Crohn's disease. So I think that that aspect is probably another clear area or certain emulsifiers in ultra-processed foods might exacerbate gut health, especially in conditions like Crohn's and maybe inflammatory bowel syndrome. So, yeah, that's another independent pathway. But yeah, so I've been

• 1:37:44Speaker 01

  mostly focused on the obesity side of things and trying to figure out, well, what is it about diets high in ultra-processed foods that might be driving this process? And that's kind of led us down to a couple of different areas. One was how quickly these foods are often eaten. That tends to drive people to overconsume calories. Folks like Karen Ford and Kay DeGraff have shown that textural-based properties of these foods, they tend to be softer, easier to chew and swallow. Maybe by the time, you know, you've got the signal that you've eaten so many calories, it's already too late because you've eaten them so quickly. I think that's in the oral sensory properties of doing that, I think, is part of the story. But I think it's not the major story. I think the major story is the fact

• 1:38:29Speaker 01

  that these foods tend to be, they have their food matrix disrupted and they tend to be dried up. So in the ingredients that are used, drying them out is important for shelf life and microbiological safety, right? The bacteria grow less well in dry environments. But in that process and removing the water essentially from the foods, you're also concentrating the calories. You're increasing its so-called energy density. So the number of calories you get per bite of ultra-processed foods tends to be quite a bit higher, even if the amount of fat isn't any different. Because fat is often considered, because it has twice the calories per gram compared to, you know, carbs or protein, often we think of high-energy

• 1:39:12Speaker 01

  dense foods as being high in fat. Well, actually, they can just be drier, less water, and that's another way to concentrate the calories. I think that's driving most of the effect and we've designed a study where we have people consuming a diet that's still 80% calories from ultra-processed foods from this broad category, but we lowered the energy density of the diet typically by diluting it with, you know, fruits and vegetables and legumes and things like that, but still having most of the calories coming from ultra-processed foods. And when you do that, people eat many, many fewer calories and they don't overconsume calories. So that's at least one factor. So thinking about how calorie dense the foods that you're purchasing are and how you're

• 1:39:56Speaker 01

  incorporating them into meals, I think is a really important consideration. The other property that we've kind of looked at is whether or not there are combinations of nutrients that exceed certain thresholds together that you typically don't find in nature, so-called hyper-palatable foods, foods that are either high in fat and sugar or fat and salt or carbs and salt, both together, they also seem to drive people to consume more calories. And so by focusing on these two aspects, I think you can get at most of the effects of ultra-processed foods on overconsumption of calories. So just a lot of things for policymakers, if you wanted to subcategorize ultra-processed foods that

• 1:40:40Speaker 01

  are potentially problematic from a overeating standpoint, you should focus on those two properties, hyper-palatability and calorie density. If you're a shopper, it's harder, right? Because then you have to take your calculator out.

• 1:40:51Rich Roll?

  Yeah, but from a consumer perspective, it's sort of like, was it Oliver Wendell Holmes? Who wrote the Supreme Court opinion about obscenity? It was like, you know, you know it when you see it. It's like, it's impossible to define. But it's like, with it, like, everybody knows, you know, oh, like, you kind of know it when you eat it, you know, it's like, oh, can I not stop? Can I only have one and walk away? Like, part of, I think that's a probably a pretty good rule for anybody.

• 1:41:14Speaker 01

  That is, that is a pretty good rule.

• 1:41:15Rich Roll?

  But me, I would imagine there are, you know, not so great ultra-processed foods out there that are counterintuitive, like, oh, I thought this was healthy and now I just realized like this is actually, you know. It's so much more calorically dense than I realized, or you know, it has all these dark matter chemicals in it, as you say, or something like that, that I wasn't even aware of.

• 1:41:36Speaker 01

  Or alternatively, there's probably also some foods that many people would all agree are ultra-processed, but are probably perfectly fine.

• 1:41:44Rich Roll?

  Like, what would one of those be?

• 1:41:46Speaker 01

  Um, yeah, you put me on the spot.

• 1:41:48Rich Roll?

  I don't know, but yeah, now I'm gonna be recommending people to eat an ultra-processed.

• 1:41:52Speaker 01

  I mean, I think that many of the whole grain breads that you can get that have preservatives in them, that would categorize it as ultra-processed, was that those would be some examples.

• 1:42:01Rich Roll?

  But the truth is, and you know this, like, you know, everyone's obsessed with protein, we didn't even talk about protein, that's like a whole other podcast.

• 1:42:09Speaker 01

  It's a whole chapter.

• 1:42:10Rich Roll?

  Whatever, I know. But, you know, we're so focused on the wrong things. Like, you know, protein, like, we're not really, you know, having a crisis of people like not getting enough protein if they're just eating a variety of foods in their diet. But what we are having a problem with is people getting enough fiber in their diet. And if you were to just focus on that, like, how can I increase my fiber intake by, I don't know, 50% or 60 or 70% into the new year? Wouldn't that solve a lot of problems for people? Or is that too reductive?

• 1:42:43Speaker 01

  It is too reductive. I'll tell you why, because in our ultra-processed diet studies, people ate the same amount of fiber.

• 1:42:49Rich Roll?

  Hmm.

• 1:42:50Speaker 01

  Because we gave them fiber supplements. And it didn't change the fact that they ended up way more even.

• 1:42:55Rich Roll?

  It's interesting, because I know when I, the more that I, like, if I make sure I'm eating a lot of fiber, then it just crowds out room for eating the other things.

• 1:43:02Speaker 01

  Yeah, you're getting it mostly from, from whole foods.

• 1:43:05Rich Roll?

  Yeah, I mean, when I say fiber, that's what I mean.

• 1:43:07Speaker 01

  That's what you mean, right.

• 1:43:08Rich Roll?

  I'm premising on that.

• 1:43:09Speaker 01

  Yeah, yeah, so that's different, right? So, and there's multiple forms of fiber, right? But the way we sort of set it up in our studies, I mean, these folks are eating 50 grams of fiber a day in both diets. In one case, it's coming from, mostly from a fiber supplement. And yeah, you've got lots of ultra-processed foods now that are adding fiber to a supplementary fiber to their, you know, sugar candy bars, right? And so, again...

• 1:43:31Rich Roll?

  Which is like greenwashing. I mean, you talk about that also, it's sort of, that's problematic, the fortification of processed food.

• 1:43:37Speaker 01

  Right, and we see the same thing with protein, we see the same thing with fiber, we see the same thing with people talking about low carb cookies and whatever, yes. So they attach, you know, this, something that in most contexts might be beneficial for the people who are trying to eat according to that dietary pattern, and then they've created these products that seem to fit within that dietary pattern based on some reductive thing like fiber, or like protein, or something like that. And so I think that that's kind of what we're seeing here. And in fact, that's kind of what we did in our study, right? We did the simple thing, which is, oh, if I'm going to focus on fiber, I'm going to give people a fiber supplement. We'll get fiber up to 50 grams a day, and that's what they ate. And, and yeah, it didn't have the positive benefits that...

• 1:44:20Rich Roll?

  But what if they had to eat celery, or like, just some like, you know, whole food?

• 1:44:25Speaker 01

  Right. Well, that's, that's the point, is that in the minimally processed diet, that's where they're getting the fiber. And in fact, yeah, that's a big contribution. And it's correlated and with things like energy density, right? So these high fiber whole foods tend to be, have lots of water associated with them as well, right?

• 1:44:43Rich Roll?

  Yeah, they're low calorically, yeah.

• 1:44:45Speaker 01

  Yeah, so these things kind of tend to go together. And so that's another problem in nutrition science, right, is that you have these things, like food is not like one thing, right? So you say, well, was it the fiber? Was it the low calorie density? Was it the phytonutrients? Was it, you know?

• 1:45:00Rich Roll?

  It's infuriating. There's no end to the amount. You could, whatever randomized control trial, you're never going to be able to like, how are you going to solve this problem?

• 1:45:08Speaker 01

  Well, I think the point is, is that we have to make incremental progress. I mean, one of the things we say in the book is nutrition isn't rocket science, it's harder. Because of these substitution problems, if you use real foods, you kind of got to think about, you know, what have you replaced it with in your study? The fact that, you know, there's still all of these things about foods that we don't even, we don't, haven't even identified what's in them, the nutritional dark matter that you talked about, whether or not they're important for health is still an open question. So, yeah, I mean, you could throw up your hands and say, we know nothing, but that's not true, right? We do know a lot. And we're making incremental progress. And I would say, given the anemic funding that nutrition science has had over the past several decades, we've actually made quite a bit of progress.

• 1:45:53Speaker 01

  But yeah, there's a lot more to do. And I'm excited about participating in that science in the future and figuring some of these things out, but we're not going to figure it all out. We have to kind of prioritize our list of topics of what's the most important thing to recognize. And I think that that's where reductionism can come into play. I'm very, I'm intrinsically, as a physicist, a reductionist of thinking, well, yeah, if we can solve this part, we'll get to like 80% of the effect and then we'll work on the rest of the 20%, which will probably be five or six things contributing to that smaller effect. And just sort of breaking out what is the most important question and most important effect to kind of account for. My view is that right now, one of the most important effects that we need to understand

• 1:46:38Speaker 01

  is what is it about different food environments that causes people to consume vastly different amounts of calories? And how does that impacting actually our biological systems that are regulating body weight? Because, I mean, it's still just amazing to me, right? And that we've seen this over and over again, not just in humans, but in, in animal studies over and over. You just shift their food environment in certain ways and without trying, they spontaneously choose to eat very different numbers of calories and regulate at a very different body weight. We need to understand that. And I think we're making progress.

• 1:47:14Rich Roll?

  I mean, that's consistent with the Blue Zones findings, you know? It's, it's, it's not about individual choice. It's about like where you live and is that environment conducive to health? Not just in terms of the food that, that is within arm's reach, but you know, is it a place where you have to walk a lot and you're engaged in some kind of low-grade activity throughout the day and you're in a community and there's a faith-based aspect to that? Like all of these factors, like you can change the food environment, but there's also the psychological factor. And you know, like how you share love through food and all the, that's where it gets, you know, it just, it just mushroom clouds into like a million variables.

• 1:47:53Speaker 01

  Yeah. Yeah. Health isn't just about food and it's not just about metabolic health, right? It's all these other things as well.

• 1:47:59Rich Roll?

  So if you were gonna design, like, what is the ultimate study that you would like to perform? If, like, funding was not an issue and it was all green lights all the way, what is the randomized control trial? Or what is the study that you would construct to help you answer the question that you're trying to answer?

• 1:48:15Speaker 01

  Yeah, I think it's multiple, again, it's multiple parts of research, the research community working together, right? We don't have the ability in humans to measure the kinds of things that we can measure in, for example, animal models and mice in particular, to kind of manipulate neural pathways and measure specific populations of neurons. And people are making a lot of progress there, but we do need the parallel human studies to measure and manipulate food environments in very controlled ways and observe how they affect, how do they affect different kinds of people, how, um, living with their families, for example. And that's why, you know, what we were proposing was a facility to be able to conduct those kinds of studies, like, in controlled manipulations of the food environment writ large, not just

• 1:48:58Speaker 01

  the foods that you present to somebody on a plate, but the overall marketing of foods, the experience that they have on how frequently people are, you know, buying foods in restaurants versus preparing them, uh, themselves in their, you know, little local apartments, research apartments, or something like that. How can we actually do studies where we can do very practical experiments manipulating the food environment to see what policies might actually be effective, right? Like, we talk a lot about policies, uh, like menu labels and whatnot in front of packed labels, and we do a little bit of analysis of that, but we don't really do randomized controlled trials of that in small populations of people.

• 1:49:39Rich Roll?

  Does a warning label actually work?

• 1:49:41Speaker 01

  Right. Well, people do investigate some of those things in isolation, but what I'm talking about is what if we had, like, a community of people where they would come and live with us for a month or two, right? And, uh, we would switch up, you know, in a cafeteria-like setting, you know, the prices of different items, or the quantities that we were giving to people, or change the formulations of those items, and periodically measure physiological functions and biomarkers and whatnot, and really try to understand what changes in the food environment, kind of in this broader sense, are actually contributing to people's behaviors.

• 1:50:20Rich Roll?

  That's almost like creating your own Truman Show.

• 1:50:23Speaker 01

  Yeah, sort of.

• 1:50:24Rich Roll?

  Like these people where everything they interact with is a variable that you're controlling.

• 1:50:29Speaker 01

  That's right. But I think that the interesting thing is, I think that that kind of study would be a lot more humane than the kinds of studies that we've been doing so far, where people basically come and live in a hospital ward for two months sometimes, isolated from their families, right? But you could envisage a way of doing this kind of research that is actually more comfortable and enjoyable for participants and is developing a much richer dataset that you could have as, you know, you could clearly still have your primary outcomes as being, this is the main point of the experiment. We're exploring a whole lot of other things simultaneously in ways that were previously just free variables.

• 1:51:10Speaker 01

  And now we're able to kind of control them and get better answers to these kinds of questions and enroll different people from different patient populations and different ages and different parts and stages of life. Yeah, I think that it would just be an incredibly useful resource. And so the specific trial, I think, is less important than the ability to do these kinds of studies. And what would we need in order to kind of do that? And we're not talking about billions of dollars. We're talking about tens of millions of dollars to create such a facility. The way I sort of think about it, kind of going back to my physics days, is physicists don't have, you know, 20 different particle accelerators around the world and everybody has their own little unit. They build a big one. And

• 1:51:53Speaker 01

  the people who have the best ideas for the best experiments basically submit grants to conduct those experiments at that facility. We need the equivalent of the big particle accelerator for nutrition research. And if we did, for human nutrition research, if we did, I think we would get answers to these questions a lot more efficiently.

• 1:52:12Rich Roll?

  There's gotta be a billionaire out there who's like, "Yes, this is what I want." But for him, it's like buying a Starbucks, "Here you go." You know what I mean? I think we all want these answers.

• 1:52:23Speaker 01

  Yeah.

• 1:52:24Rich Roll?

  And I feel optimistic and confident that somebody's gonna foot the bill for something like that, because these are answers that we all want. The work that you're doing is vital, and I'm certain that you're gonna find your next spot. And I want you to be able to do all of this research, because the world needs you, Kevin. And I appreciate you coming here and talking to me today.

• 1:52:46Speaker 01

  Thanks so much.

• 1:52:47Rich Roll?

  Yeah, so everybody, check out Food Intelligence. I'll link it up in the show notes. And if anybody wants to learn more about you, where would you direct them?

• 1:52:57Speaker 01

  I guess website, kevinhallphd.com.

• 1:53:00Rich Roll?

  Yeah, and more will be revealed about where you're gonna go next.

• 1:53:05Speaker 01

  Indeed, we'll figure it out.

• 1:53:06Rich Roll?

  Well, please come back and talk to me again. I really appreciate you coming here today.

• 1:53:12Speaker 01

  My pleasure, we'll do it.

• 1:53:13Rich Roll?

  Peace.

• 1:53:21Rich Roll?

  All right, everybody, that's it for today. Thank you so much for listening. I really do hope that you enjoyed the conversation. To learn more about today's guest, including links and resources related to everything discussed today, visit today's episode page at richroll.com, where you will find the entire podcast archive, as well as my books, Finding Ultra, The Voicing Change Series, and The Plant Power Way. If you'd like to support the podcast, the easiest and most impactful thing you can do is free, actually. All you gotta do is subscribe to the show on Apple Podcasts, on Spotify, and on YouTube, and leave a review or drop a comment. Sharing your show or your favorite episode with friends or on social media is, of course, awesome as well and extremely helpful, so thank you in advance for that.

• 1:54:05Rich Roll?

  In addition, I'd like to thank all of our amazing sponsors, without whom this show just would not be possible, or at least, you know, not free. To check out all their amazing product offerings and listener discounts, head to richroll.com/sponsors. And finally, for podcast updates, special offers on books and other subjects, please subscribe. Subscribe to our newsletter, which you can find on the footer of any page at ritual.com. Today's show was produced and engineered by Jason Camiolo, along with associate producer Desmond Lowe. The video edition of the podcast was created by Blake Curtis and Morgan McRae, with assistance from our creative director, Dan Drake. Content management by Shana Savoy, copywriting by Ben Pryor. And of course, our theme music, as always, was created all the way back in 2012 by my

• 1:54:49Rich Roll?

  stepsons Tyler and Trapper Pyatt, along with her cousin, Harry Mathis. Appreciate the love, love the support, and I'll see you back here soon. Peace. Plants.