Protein, Pyramids, and Politics: The Forgotten Stories and Controversial Science Behind Government Dietary Advice

Today the federal government issued new guidelines for diet and nutrition. Unless you've been hiding under the Great Pyramid, you've probably heard that the new food pyramid is flipped. The talking point, forget everything you thought you knew about healthy eating. We live in a brave new world, folks, and as part of that earlier this year, the Trump administration

issued brand new dietary guidelines for Americans. Unsurprisingly, these have been quite controversial, and we are going to get into the details this episode of Gastropod, the podcast that looks at food through the lens of science and history. I'm Cynthia Graber, and I'm Nicola Twillie, and forget what the dietary guidelines say.

My first question is, what are they? Who comes up with them?

“And are they the same as the numbers on the back of food packages, those nutrition labels?”

What are all these nutrition numbers based on? How does the government figure out what we need to eat, and what difference does it make to what we do actually eat and to our health?

It's all a mystery to most of us, but never fear, we are here to get to the bottom of it.

This episode is supported in part by the Alfred P. Sloan Foundation for the public understanding of science, technology, and economics, as well as the bar is welcome fun for our coverage of biomedical research. Gastropod is part of the Fox Media podcast network in partnership with Eater. What goes up must come down, except when it comes to gas prices.

The price tends to rock it up very quickly at the pump, as when crude oil prices go up, but gasoline prices tend to take a little bit longer to go down in many cases. This week, I'm explaining to me why gas and everything else is so expensive these days. Find new episodes, Sundays, wherever you get your podcasts. So, government advice on what to eat comes in three main flavors.

“There's the measurement part of determining the exact quantity of each nutrient we need.”

Then there's translating those numbers into what they mean in terms of actual food. And then these days, there's also a visual guide that helps communicate the ideal diet. And all three of those things get argued about a lot. To understand today's controversies about government dietary guidelines and about how much of anything we should be eating, we have to go back to where it is.

It all started. For most of human history, governments did not figure out what people should eat and then tell them what to do. In part, that's because for most of human history, the main concern was just getting enough food.

But it's also because the understanding of how food affects our health was very different in the past. It wasn't until the 1800s that scientists started analyzing the composition of food, figuring out what different foods were made of in terms of protein and carbohydrates of that, and learning how those different nutrients affect our bodies.

In the 1890s, building on this emerging science of food, an American chemist named Wilbur

Atwater became the first chief of nutrition investigations at the U.S. Department of Agriculture.

In that role, he basically took the first stab at putting an exact number on how much of different nutrients we need to eat, using science to try to understand how food fuels humans. So Wilbur Atwater was interested in using techniques of physiology to measure human metabolism. And this kind of metaphor of thinking of the human body as a machine. Hannah LeBanc is a historian of nutrition science, and she told us that these days Atwater

is mostly known for figuring out how to measure calories in food, and also how many calories people burn to stay alive and do things. In fact, Atwater was one of the stars of our episode of the end of the calorie. The problem to be solved with the question to be answered was what are sort of basic human needs, and could they be measured?

And then, could you use those numbers to create a standard, a standard that would quantify

“the minimum amount necessary to keep people, primarily men, working efficiently?”

In America, this was the height of the Industrial Revolution, and men were the machines that kept the nation's factories running. Atwater was really a pioneer here in the field of figuring out how much of specific things we need to consume. At a time when we were just starting to learn what all the nutrients in food even were.

The only one scientists really knew enough about to measure were protein fat and carbohydrates. Atwater had traveled to Germany where researchers had developed new machines that could measure how many calories a person was burning.

For his first big publication about what Americans should eat, he took that initial German

data and added a little padding to arrive at how many calories an American working man needed. Because Americans were Carter, he said, "Atwater also had machinery to measure how many calories are actually in the food we eat." He then came up with what are called the "atwater factors."

The number of calories in each gram of fat, carbs, and protein. This allowed him to come up with a nutrition table for foods that were popular at the time, like cheese, butter, oysters, macron, mutton.

overall.

“This was early days, so his experimental data was really pretty minimal.”

So atwater checked his work with observation. He was seeing how much healthy, non-starving people ate on average, and then extrapolating from that to get at how many calories and nutrients they were using. Atwater used this information to help people, mostly men, mostly men working in factories, to help them, or their wives, come up with inexpensive meal plans that would meet their

coloric needs. His plans were unsurprisingly, heavy, and fat protein and carbs, things like beef shoulder, canned salmon, potatoes, oatmeal, and butter. He didn't include fruits and vegetables because they didn't have enough fat protein and carbs per dollar.

The science behind atwater's nutrient recommendations and meal guides might have been limited,

but when he published his recommendations in 1894, it was the first science-based government

dietary guidance in America. For the first time, there were target numbers. For how many calories and how much protein fat and carbohydrates people needed to consume for a healthy diet. Plus advice on how to get there.

And then, science discovered vitamins. In the early decades of the 20th century, nutrition researchers start to point to these

“accessory food factors that appear to be important for human health, but exactly what they”

do and how they work is a little bit mysterious. And so they're identified primarily by what their absence causes. In other words, disease. So at this point, nutrition scientists and government officials started realizing that it wasn't sufficient to just recommend enough calories to ward off starvation.

They also had to recommend enough of these accessory food factors to prevent people from getting sick. The new understanding of vitamins inspired a home economist named Hazel Steebling to try to come up with meals that would help keep people healthy. She was also working at the USDA and she wanted to help people who are struggling during

the great depression. She wanted to help them eat the right foods to get the right levels of nutrients.

And she was the first I know of to propose a kind of quantified standard that could be used

for vitamins and minerals, and she does this first in 1933.

“I think she includes two vitamins and three minerals at the time.”

So it's still a fairly limited set of nutrients. Like Atwater, Hazel also came up with a few different diet plans to help people hit those goals. And because it was a time when people were really scraping by, she made sure to design a super low budget one.

The lowest level diet is still meant to cover all of the sort of baseline needs. The floor of vitamin and mineral requirements, so that it won't anyone who's using this model diet wouldn't get pylagraph, for example, or scurvy. You get pylagraph if you don't have enough niacin or vitamin B3 in your diet, and scurvy is a lack of vitamin C, but it doesn't have, what she says doesn't have much margin

of safety. And then she has these other model diets that sort of go up in their expense, but provide more and more nutrients. Hazel based her vitamin recommendations on some scientific studies, many of which were carried out in her government department, the Bureau of Home Economics.

But just like with that water, that wasn't a lot of data to draw on.

Human nutrition researchers in the early 20th century always joke that they're sort of

behind the animal researchers, because the USDA had research for a long time, the nutrition requirements of various domesticated animals, cows, and horses, and pigs. So she's probably using a combination of some of the early human research, and some of the animal research to come up with what mammalian nutrition needs look like. Humans are not exactly the same as other mammals in terms of our nutritional needs, but

you do what you can with what you have. This sounds like a pretty sensible public health strategy based on the latest and most accurate science Hazel could gather, but right from the beginning her meal plans and the very idea of the government making food recommendations. This was all subject to pushback from the food industry.

So she's attacked by the wheat milling industry because her more expensive diets include proportionally less wheat and more meat, milk, fruit and vegetables, and they lobby to actually have a provision in the next agricultural appropriations bill to cut her salary, or to cut the salary of anyone who is promoting lower consumption of any wholesome food. Despite this industry, Hazel's work was well received.

The League of Nations, which was the four-runner to the UN, followed in her footsteps and issued some dietary recommendations of its own in the 1930s, and it encouraged its member nations to use these scientific standards to guide their food and agricultural policies. Less than a decade later, in 1941, there was another war on the horizon. The U.S. had not yet fully emerged from the Great Depression, and there was also a concern

that the American men being called up for the draft just weren't healthy enough to be successful soldiers. Apparently, about a quarter of men who were called up were found to have signs of malnutrition.

do it, we can build here in America, a tougher, more vigorous nation."

“And so, in 1941, President Roosevelt calls a national conference to discuss nutrition for”

a national defense, and the nutrition is there are very aware that they have a moment in

which they have the nation's attention, sort of for the first time, and that they'll

have more funding and more backing than they've ever had before. At this conference, the man in charge of the National Research Council's Food and Nutrition Board decided that the first step to solving the malnutrition problem in making sure Americans were eating an optimal diet, was to build on Wilbur at Wouter in Hazel's Deepling's work, and come up with a standard target for each nutrient.

He turned to three home economists, one was Hazel's Deepling, of course, and the other two were named Helen Mitchell and Lydia Roberts. They were given the task of coming up with these target goals for each nutrient, literally overnight, they had less than 24 hours. And so, as Lydia Roberts tells the story, they spend the night.

I know hotel room, sort of trying to hash out the best evidence that they have.

She says while she assumes that all the men are out on the town, and then presents the

fact that this is far too complicated, a problem to solve in one day. Lydia told the chair of the board that, quote, "It couldn't be done, that the evidence was too scanty and too conflicting." And for her troubles, he then appointed her head of a new subcommittee, tasked with getting it done.

“And she takes a very deliberately democratic approach, that's how she describes it.”

So she and her committee gather all of the evidence that's available, all the published evidence. But they also contact 50 nutrition experts for their best recommendations, their best understanding of the field. Home economists had started compiling data on things like what fruits and vegetables had

what vitamins, though even that was really shaky in terms of quantifying the specifics. But as Wilbur at Water and Hazel Stubling had already discovered, it was also incredibly difficult to come up with figures on how much of each nutrient people actually needed. Yeah, a lot of the science at the time was, um, based off of these diaries that had been done, both across Europe, uh, some in New York, that at Water had done, and it was just

observed intakes that were presumed to be, keep people healthy. Kevin Klatt is a nutrition scientist at the University of Toronto, and he says that these types of observed intakes, figuring out what people are actually eating and coming up with what keeps us healthy from that information, they're still an important tool today, but they're known to be weak, it's not conclusive data.

As we've said repeatedly in past episodes, people are notoriously bad at accurately reporting what they're eating, even when they jot their notes down right at the time, plus most people wouldn't have had like a food scale at home. But in some cases, the self-reported data was all scientists have had to work with.

“And you have to remember, a lot of these nutrients had only recently been identified.”

The vitamins, especially. Take Vitamin A. There wasn't a lot of research on it. And in the studies that did exist, they only real way to tell whether someone was getting enough Vitamin A was to make sure they weren't getting too little, because if they were getting too little, they would develop something called night blindness.

Their eyes had difficulty adjusting to the dark. So one of the experiments that it looked at was conducted by the Bureau of Home Economics on a grand total of five employees who volunteered to spend several months eating a diet that was adequate in all nutrients other than Vitamin A.

And they eat this diet until basically they develop night blindness.

And then they continue to eat that diet plus cod liver oil until their eyesight returns to their own baseline. Cod liver oil was known to be a great source of Vitamin A. So that was one figure that was useful to the committee, even though it was based on only five people, which really isn't enough for a good scientific study.

Another kind of accidental study happened when a group of Danish prisoners developed night blindness after eating the prison rations, and so researchers gave one group milk and another group didn't get the milk, and they figured out what it took to get them back to normal. Milk also contains Vitamin A.

On top of those, studies there was some data from horses that were given different diets, some super low in Vitamin A, and then tested on how close they came to obstacles, but in their path at night, as the way to figure out how well their vision adapted to the dark based on how much Vitamin A they were getting. The studies might have been weak, but then there were other problems with coming up with

a target for Vitamin A. Some foods like, yes, milk and cod liver oil have straight Vitamin A, but some foods like carrots have caratine, which your body can turn into Vitamin A. There had been a study that showed you had to eat two times as much caratine to get the same amount of Vitamin A as if you got it straight from cod liver oil or milk, but how much of each kind of Americans consumed buried considerably geographically and by income level.

And then the final issue with setting a target is that your body can store Vitamin A in the liver and use it later if you're not getting enough.

history then has some bearing on how much Vitamin A you need to continue to eat, because if you've

been well and nourished for much of your life, then you have a little bit more leeway, than if you've not been well nourished and you don't have the same stores of Vitamin A. All of these challenges were compounded by a more fundamental problem, figuring out the big picture goal. And all the previous attempts to come up with daily requirements that we've talked about, the government's goal was trying to make sure people ate the minimum

amount of nutrients to avoid disease. But the goal of this new committee, the one Lydia was in charge of, it wasn't just to avoid disease, it was to ensure that the American public and in particular, the American warfighters, that they were in the best health possible.

So if you consume enough that you're avoiding Pilagra or Barry Barry or Skurvy,

“but not enough to really be operating at your full capacity, that's what they fear,”

that multiplied over an army or a factory that can actually affect not just people's health and well-being, but the outcome of the war. And so they're aiming for kind of aspirational standard, that if everyone hits it, they can feel very secure that everyone has really good nutrition. A nation with bottom morale and greatest strength of mind in the world is ever known. Boom can build a new America. And B.D. Lydia was on it. At the end of all of this, she and her

gang had a range of pretty weak data on Vitamin A that was mostly based on avoiding too little. Plus they had this larger aspirational goal of optimum nutrition, and so what they did was

average all the results of the existing studies and add 50 percent just to be on the safe side.

This process was a little different for each Vitamin. Some like Vitamin C had a lot of data that experts had wildly conflicting opinions on. Some like Niacin had none, and so had to be guessed at based on studies and animals that showed it was proportional to Vitamin. It took a year for Lydia's committee to wrangle all of this, but the final result was, Drumroll, please. The recommended daily allowances, RDAs. These were official government

recommendations for the amount of eight different nutrients that men or women of average weight should aim to consume. When her committee presented these new RDAs to the Food and Nutrition Board,

“Lydia was like, "We do have something great for you, but it's not perfect." I think it's really”

interesting that when Lydia Roberts presents these, she's very upfront about all of the limitations. That this was a standard that was needed because of the war, but it's not one that the field is really prepared to create. Cathy at the side, Lydia's shiny new RDAs started to be used for all sorts of things right away. So it's used by the quartermaster to create rations and plan menus for the army. It's used by industrial canteens. It becomes part of the educational materials

that the Bureau of Home Economics produces for home makers, the school lunch program. The RDAs quickly became the backbone of official government food planning. But Lydia kept pointing out that these RDAs were meant to be preliminary. Pretty explicitly, like don't put too much stock in these numbers, we've had to do a lot of guesswork to create these. So she says in, I think it's in 1944 at a nutrition conference that she expected everyone to want and update as soon as possible

as more research is coming out. And as Lydia later wrote that the response was not what she expected. I have the quote here. Instead of welcoming a revision, almost everybody says don't touch them. We've got them all in our books now and we've been doing everything according to them. So leave them alone. Change is hard. Of course science did not stop 80 plus years ago and our RDAs have indeed been updated. And each time that happens, there's drama and chaos. That story after the break.

It's today explained. President Trump has not made a coherent case for his war in Iran. And last night he said he's not ending it yet. We're going to hit them extremely hard over the next two to three weeks. We're going to bring them back to the stone ages where they belong. His ally Tucker Carlson has been making a very coherent case against the war. Because it doesn't serve American interests in any conceivable way. And let me just say that if it

does in some way serve the interests of the United States, I'd love to hear it. I haven't heard it. On Tuesday, we asked Carlson about his break with Trump and about how the Trump coalition is splintering as some young conservatives abandon the president and embrace something darker. It becomes like all of a sudden like, hey, you kids, why you listen to Elvis Presley and that rock

“music is bad. Like all of a sudden, when does controls the conversation and becomes the cool kid?”

And the net effect is to make the Holocaust a joke. Today explained every weekday wherever you get your podcasts.

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That's true. You can subscribe to the Curiosity Shop on YouTube or follow in your favorite podcast app to automatically receive new episodes every Thursday. For the last 10 years, everything in American politics has basically revolved around one man. And as a political journalist, who came of age during Donald Trump's rise in 2016, I've had a front row seat. I am officially running for president of the United States.

It's going to be only America first. America, come first. Thousands of supporters of President Trump storm the U.S. Capitol Building. But is it possible to talk about politics without talking about Donald Trump? That's the question I'm going to ask in our new show from box. The idea of like a post Trump, or not exactly Trump, focus show, can exist because he's not really driving any agenda items.

“It's really does feel so reactive. You know, I think this around thing is also going to cause a big”

split in the GOP. So far, it doesn't among like people who say their MAGA voters are still with Trump.

But like, for the first time, you see, on a major issue, open opposition from the start of this war.

I'm a state-haunting. And welcome to America, actually. One of the first things that the new RDAs were used for was to measure whether the U.S. diet, the foods Americans were eating every day, whether it was up to scratch. The bureau of home economics conducted food consumption surveys, people would report what they didn't, and that was used to try to figure out if they'd eaten enough, say, vitamin A. And a lot of people fall short.

But it's not clear what that means. On an individual level, it doesn't mean a whole lot, because they know there's so much variance in people's needs. But even on a population level, that doesn't necessarily mean people are malnourished. It just means they're not meeting this

really fairly high standard. Those first RDAs were deliberately aspirational, but people

realized pretty quickly that they were really unnecessarily high. So a lot of the early updates to the RDAs just lowered them. Scientists also continually learned about the existence of more

“nutrients that were important for our bodies. And they learned more about exactly what those”

nutrients do in our bodies. We have the luxury of knowing like we know that this nutrient is a co-factor for this enzymatic process. And so we're going to measure that enzymatic process and figure out how much of the nutrients needed for that to like fully function. And at the time of 1943, they didn't know most of the spiral chemistry was not really figured out. There was maybe some studies from animal models and a little bit from humans where we thought, okay, we think

that this is a nutrient, but it's cellular and physiological role really wasn't determined. And so all that data was really missing at the time. And so that all slowly develops on sort of a nutrient by nutrient basis over time. Another thing that got more and more precise over time was tailoring the RDAs to specific population groups with special requirements like infants, children, pregnant women, and the elderly. But even as the science behind RDAs got better,

the way Americans were thinking about the relationship between nutrients and health shifted pretty fundamentally. For one, people started to not just get their nutrients and food, but they started taking their vitamins in pill form. They figured they have to meet these targets. You can get it all in a pill. Awesome. And then people started thinking, well, hitting the target is great, but more is more right. In fact, a scientist named Linus Pauling, he did groundbreaking research

on chemical bonds. He went a little bit off the rails later on in his career when he decided that if a little vitamin C was good, then mega mega doses would cure cancer and prevent infectious diseases. I myself think that a scarabic acid is probably up the more out on intake of about three grams a day or five grams a day. I three grams a day, I stir into my orange juice every morning, it only costs a half per half. This is from a lecture that Linus Pauling

gave at UCLA in 1968, three grams of ascorbic acid or vitamin C. That's more than 30 times what an adult man is supposed to get per day according to the RDA. If you were to take five grams, that'd be more than 50 times what he theoretically should be getting. Linus Pauling had won a Nobel Prize, so his words carried some weight, and he wasn't the only one advocating mega

“dosing on vitamins and minerals in the 60s and 70s. With a lot of, I think, at the wellness”

industry at the time sort of claiming that huge doses of certain vitamins and minerals like protective against cancer, people were really buying a lot of supplements. But scientists were quickly discovering that too much of a good thing can be bad. In fact, it can be toxic. They keep discovering these problems today. Getting too much vitamin C could be taxing on your

but a new study shows too much of a good thing can pose a serious risk of lung cancer in

“some male smokers. And taking too much vitamin E, any more than 260 milligrams, can be deadly.”

The early research was all focused on the harms of having too little, but suddenly scientists had to switch gears and figure out the harms of having too much, and they had to put a number on that. The RDAs were a goal, but now we needed an upper limit, too. There was another problem of abundance. The RDAs were originally meant to deal with scarcity and malnutrition and the resulting diseases. But over the next few decades, things like polygra and scurvy were no longer

a big problem in America. You see that the causes of death start to shift to things that are more chronic. And so cardiovascular kidney diseases are top things early on. And so research starts to investigate that. Scientists started to point the finger at particular nutrients that they say in excess are at least partly responsible for these kinds of chronic diseases. Salt and fats

“and really just too many calories. The RDAs were a target to avoid malnutrition, but they didn't”

have anything to say about this new problem of too much food. The food itself was also different.

We've talked about this a billion times on gastropod. By the 70s, Americans were consuming

more and more processed foods, and they didn't know what was in those foods. How good they were for you. You know, today's consumers, and of course there's all of us, are faced with an enormous choice of food. And up until now, we haven't had any way to tell what kind of nutrients, things like vitamin, proteins, are in the foods we're buying. We couldn't tell how to buy the best foods, nutrition wise, or money wise. It's Dick Van Dyke, and he's confused just like everyone else

back in the 1970s. But fortunately, the government came to the rescue. In 1973, they started printing nutrition labels on the back of food packaging, showing the different nutrients as a

percentage of your daily values. So now every single one of us can eat better if we use nutrition

labeling to plan better balanced meals. We're going to show you how to do it. The new labels will show you how many minerals, vitamins, fats, carbohydrates, proteins, and our old friends, calories are in the foods you eat. Read the label, set a better table. This sounds really specific and certain, but as was the case for Lydia Roberts and her new RDAs in the 1940s, there was a lot of fudging going on. Originally, the RDA came in two flavors, one for a man and one

for a woman, but on the new label, the daily value was just the highest of the two. And how much of a percent of your daily value that food represented was based on whatever the manufacturer thought a serving size of their product was, and whatever nutrients they estimated that each ingredient in the serving contained, which they mostly figured out, using data gathered from rats in the 1930s. All those caveats aside. The government came up with these specific and detailed new labels,

and the FDA hired Dick Bandike, and a few backup singing vitamins and minerals for their PSA to help everyone learn how useful these new labels were. This is Dick Bandike for the Food and Drug Administration, reading the labels. Astonishingly, relying on Dick Bandike in nutrition labels was not enough to turn around the tide of diet-influenced chronic disease. So, after an influential report on the not so great state of the American diet came out in 1977, the government decided

to introduce another new form of food guidance. The dietary goals, the RDAs were numbers aimed at nutrition and health professionals who would know how to interpret them, but these dietary goals were aimed at ordinary Americans. They told people in plain English to eat more carbs and cut back on fat and salt. It makes sense to me that the government would provide some kind of advice about what healthy food looks like. And the attempt to translate that from these

really abstract, quantified things like vitamins to actual food also makes sense to me, because people don't eat nutrient-safe food. And because the government wanted to help people understand just what food they should be eating, the people in charge of this initiative came up with a now famous visualization of the ideal diet, the food pyramid. The USDA introduced the mighty food pyramid in 1992. It is extremely groovy looking, sort of three-dimensional with little white,

fat and sugar dots sprinkled like stars on a black background. Bats oils and sweets are at

“the top of the pyramid to show you should consume them sparingly. And there's two big plates”

of pasta and a couple of loaves of bread at the bottom plus some crackers to show that grains should form the bases of your diet. If there was a lot of controversy around the dietary

we should be eating, for instance. One of the arguments was that there just wasn't enough science

around what actually caused chronic disease. This is the bait over okay, we don't have perfect evidence, so what do you do when you're not perfect evidence? Do you make a cheeky progressive

“viewpoint and make a preliminary recommendation with the hope it's going to help public health?”

Or do you take a more conservative recommendation and say, the evidence isn't quite there yet, we're not going to make a recommendation yet. This is an ongoing tug of war today, but in the 80s and early 90s, all this controversy around the new government messaging added up to a sense of confusion. At this point in his treat, the government took a long hard look at where it was in terms of nutrition recommendations and it felt the need to reorganize. The dietary goals and

the new food pyramid were not coming out of the RDAs, but the RDAs were supposed to be the official

recommendations, but meanwhile, the RDAs were still about preventing deficiencies rather than dealing with chronic diseases and vitamin mechidosis. The RDAs couldn't do enough of what we needed, so the government decided to come up with an entirely new system. They are essentially replaced altogether with the system of dietary, it's called the dietary reference and takes.

“Or DRIs, and where the RDAs were just one number to rule them all, the DRIs contained”

multitudes, including an RDA. But so what the DRIs do is that they move from the single value system of the RDA to a probabilistic system assuming that not everybody needs the same amount, and so your whole goal is to estimate what the average person would need, meaning the amount of the nutrients that would meet the needs of 50% of people, but wouldn't meet the needs of 50% of other people. Okay, so that's the base number. It's something called an EAR, an estimated

average requirement. It's useful from a public health point of view. Like when the government looks at the data on what Americans actually eat to assess whether on average we're doing okay, or if there are some nutrients that on average we're missing out on or eating too much of. But it doesn't work as a guideline for individuals. Like Kevin says, if everyone consumed just the EAR of a particular nutrient, then half the population would be fine, but half wouldn't

“be getting enough. So that's obviously not ideal. So they did some statistics on that baseline”

to arrive at another number, the new RDA, which like before is more than enough for most people. Which is estimated to be what would meet the needs of 97.5% of the population. So if everybody ate the RDA, you know, 97.5% of the population will be eating more than they need. If it sounds confusing, it's because it is confusing. And to make it even more confusing, the new DRIs include ULs, which are upper limits. This is quickly becomes acronym soup.

Over time, the DRIs have included these ULs upper limits for a number of vitamins and for sodium. Those scientists don't have enough information to set an upper level for all nutrients. The idea was that this whole thing would be revised regularly like the old RDAs so that any new data would help inform the DRIs and the RDAs and the ULs and all those other fun acronyms to help them become more and more accurate. All of this would in turn inform what's called the DGAs,

the dietary guidelines for Americans. This is what the government thinks we should be eating. The DRIs are the scientifically agreed upon values that are supposed to inform the DGAs,

the dietary guidelines. The first one is about nutrients, the second is about food.

But to make sure that eating food according to the guidelines will lead Americans to consume the right amount of nutrients, the government has to do something called food pattern modeling. Where it says, okay, if you're going to recommend a dietary pattern with this many servings of grains, oils, fruits, vegetables, different protein food categories, and consume a diet that an American would typically eat, what's the likelihood that you actually

meet the dietary reference and takes? Let's take iron. You don't need to eat meat to get enough iron. You can get plenty from a diet that includes lots of beans, but Americans don't tend to eat a lot of beans. It's arguments that we're recommending too much red meat, but anytime you try and go a lower red meat, you run into issues with iron from the food pattern modeling. Actually, this is really only an issue for menstruating women. Their iron needs are higher than men,

and so if women are eating the average American diet and they cut out all red meat, food modeling, says they'd be too low. Lots of scientists want to recommend that American should eat less red meat to help prevent cardiovascular disease and cancer. But they're sort of a floor at which you can recommend for red meat because it's unlikely that people will meet their estimated iron in takes if you were to drop it to zero, for example. The same is true for like bread made

within rich processed white flour. That white flour has been enriched with full late which helps prevent birth defects. Women could theoretically get enough full late from lentils and beets and from dark leafy greens like kale, but most Americans don't tend to eat a lot of lentils and kale. The particular birth defects that can result from not having enough full late are things that happen

American diet are covered for full late does make sense. And so that means that even though whole grains have all sorts of things in them that are great for you, honestly they're way better than enriched white flour and basically every other way, the government won't say just eat all whole grains. When you do food pattern modeling and you recommend all whole grains and know or find grains, you actually get pretty low full late in takes including in those women of reproductive

“age that you're trying to help the most. And so that's why the recommendation is at least”

half your grain should be whole, but not all despite there are many benefits. These are the kinds of fun ways that nutrition science gets made into the frink and sausage of food recommendations. Then you get the process of trying to communicate those recommendations to the public,

which is also always a work in progress. The food guides that they give evolved a little bit. So you

have my pyramid in '92 and then an updated pyramid in 2005 to address critiques that starches ended up at the base of the first pyramid. They have a second pyramid and chose a five that has a guy walking up the side of the pyramid and so it's supposed to emphasize physical activity a little bit more. This is a really different and honestly pretty confusing pyramid. It looks like a rainbow of stripes going down the pyramid vertically. In the first pyramid,

the smallest level, the fats and sugars you're supposed to eat the least of, they were at the tipi top. In this one, the fats are just this tiny little yellow stripe, grains are a wide orange stripe at the pyramid and meats, fish, eggs and beans are a narrower purple stripe. And so on, it's not the greatest visual. People didn't love that pyramid either, so we get the plates in 2011. With as much drama as the Department of Agriculture could muster and with help from the

“first lady, America today got a new symbol for good nutrition. What's more useful than a plate?”

What's more simple than a plate? And the plate, you know, at least conveys like what people eat off of and it's a bit simple and like make half your plate for its vegetables. Plates, pyramids, I mean in China, they use a pagoda. Our point here is that going from the best data in the DRIs, which that data is already not set in stone because there are things we still don't know. But going from that to the dietary guidelines that take into account how most people eat,

and then from the guidelines to the visual imagery that's supposed to make sense to everybody, it's not an exact science. Plus, and this shouldn't come as a shock to anyone,

politics also gets involved, just like it always has. Like when the wheat farmers got mad at

Hazel Steebling. Take 2020. For the first time the dietary guidelines advisory committee recommended a food sustainability system rich in plant-based foods should be included in the federal government's nutritional guidelines. They suggested people eat more plant-based proteins, like beans, and cut down on meat. And of course the meat industry was a bit peeped. Casey Gallamore was the director of regulatory and scientific affairs at the North American

Meat Institute. And this was what she had to say. The superior nutrient contributions of meat and poultry products must be recognized relative plant-based protein sources. It is inappropriate and a disservice to the public to consider beans or tofu as equivalent to meat and poultry products from nutrition and health perspective because they're not. Casey has her biases, obviously, but the government held its ground until the government changed. The story of our new dietary

guidelines and the return of the pyramid knew improved an upside-down after the break. This past January the Trump administration and Robert F. Kennedy Jr., a Secretary of Health and Human Services, they released the 2025 version of the whole Shabang, the DRI, the DGA, and the image to go along with it all. These new guidelines will revolutionize our nation's food culture

“and make America healthy again. Protein and healthy fats are essential, and we're wrongly”

discouraged in prior dietary guidelines. We are ending the war on saturated fats. RFK promised a revolution. But Kevin says that's a little bit of an overstatement. Yeah, a lot of I keep emphasizing people. A lot of it is very similar. And so they didn't go off the rails saying like feed raw milk to your young children or anything or the pregnant women, which is great. But there are some pretty significant differences.

They have lots of different rationale for why that is. But they changed the protein recommendations to close to double the RDA. And like RFK promised, they do sort of in the war on saturated fats.

Yeah, so fat was the other big thing that they changed on where they basically assert that fat

naturally found in foods or healthy. And they list off salmon nuts and olives and avocado that we all might think about. But then they also say that like meat, eggs and dairy are also full of healthy fats. So what's guiding these changes you might ask? Well, according to the administration, it's that they're using the very most accurate science available. These new guidelines

as it relates to the role of our diets and the prevalence of chronic disease in the country.

These guidelines replace corporate driven assumptions with common sense calls and cold-standard scientific integrity. Kevin has read the entire 90-page scientific report and also the 418-page appendix, which is probably more than most people outside the people who wrote it ever will. And he says it goes into depth about the weaknesses built into a lot of the kinds of

“evidence that's used to decide whether a food is healthy or not. You'll remember some of these”

issues from our episode nutrition advice decoded where we explored how scientists try and sometimes struggle to figure this all out. Today, most nutrition research has done by looking at what people eat and measuring what's in that food and maybe looking at things like blood pressure or fat in the blood that might be the precursor of a disease and trying to figure out if eating a particular food would lead to that disease. But food is a lot more complex than just one nutrient and precursors

are not the disease itself and lots of other things contribute to chronic disease. So this is actually quite difficult to tease out. And all of this makes nutrition science very different from pharmaceutical testing. Drug companies have a drug, they can either give it to you or not, and a randomized blind controlled way. And then they can see whether it makes a difference or not to a specific health outcome. I'm not like, sounds great. Like we would all love to have that standards.

RFK and his colleagues promised that the new dietary guidelines would basically meet the standards

of the pharmaceutical industry. That's the gold standard. But actually, for all the reasons we just said, combined with the fact that we don't really fund good nutrition research, that's not possible. That evidence just doesn't exist. Kevin says if you only issued guidelines based on that standard, you would basically have no guidelines related to chronic disease risk at all. So it's like it's listed early on in the DGA scientific document is like a aspiration. But then they go on to

cite all different types of data, strong together in various ways to kind of come up with their

“conclusions. For protein, remember they doubled the old RDA. But when you look at the evidence”

they cite for this, Kevin says not only is it not the gold standard, but on top of that, it's cherry picked from the research we do have. It largely pulls weight loss studies as well studies that used resistance exercise training at the same time. The point here is that the studies they relied on for their protein conclusion were for people who are particularly trying to lose weight or were particularly trying to gain muscle. These are not just everyone eating their normal diet.

These cherry picked studies did show a correlation between higher protein consumption and then lower body weight and increased muscle mass, which by the way, neither of which are clearly connected to chronic disease. Meanwhile, there are a whole bunch of other studies out there looking at protein intake that the new dietary goals ignored. Like they didn't do a systematic review on all of the day, the observational data looking at higher versus lower protein and takes

“in cardiovascular disease, for example, or even a systematic review of shorter-term trials,”

looking at protein, total protein amounts and sources, and blood cholesterol, for example. So they just look at this very narrow slice of the totality of the evidence focused on weight and body composition outcomes and then make a recommendation broadly to increase the protein and take reasonably substantially. But even the cherry picked data, the studies the team used to come up with the new protein guidelines, it's not so straightforward. For losing weight, the evidence

that consuming more protein helps is really weak for people who are actively trying to build muscle, and this is only true if you're lifting weights. Eating more protein does seem to help

with muscle gain up to a point. But most people aren't bodybuilders, so basically, from most people,

there's no benefit to increasing protein and there is also good evidence that eating more meat could be harmful. And the whole point of the DGA is that they're supposed to apply to everyone. This new protein goal doesn't do that, so that's a fail for the new DGA's when it comes to following the best available science, at least on protein. With saturated fat, the issue is more that the advice doesn't add up. The language and all that they use is quite confused, because they say

all fats are good as long as they're natural, and then use all-boiled butter and beef tallow. But then they keep, okay, eat less than 10% of your calories from saturated fats. This 10% number for saturated fats was introduced in the early 90s, and it's not changed in the most recent report. Scientists say we're not supposed to eat too much saturated fat. For one, it seems to be connected to health problems, including higher levels of cholesterol,

which are tied to heart disease. The government's argument is that if you go over 10% of your calories from saturated fat, you likely won't be eating other good stuff you need, like fiber. The 10% number is one of the government's recommendations. It's the science you want to do with nutrients. The government is supposed to use that to then make its recommendations for what foods

the nutrient number says one thing, and the pyramid and food guidelines say something else.

“And so if you're following the new pyramid and the guidelines to eat more animal fats,”

you'll end up eating way too much saturated fat. So it's extremely unlikely that like you're going to say, under 10% of calories, if you're getting three glasses of home milk per day, and then choosing some fat of your cuts of meat and maybe cooking in butter for one meal a day. Another big shift is to recommend eating fewer grains and making all of them whole grains. Like we said, we are on team whole grain. They're better and almost every way than refined grains.

But if Americans actually follow that recommendation and don't also make sure to eat a lot more lentils and dark leafy greens, you're risking women giving birth to babies with spinal bifida. The only other substantive difference in terms of guidelines was a new thing. A recommendation to cut down on, quote, highly processed food. Kevin says without a legal definition of what food counts as highly processed, which doesn't exist, this is essentially

“just so much hot air. And if you have a new term with no strong definition of which foods fit”

that criteria and which foods don't, it might gain you some points with the public for saying don't eat highly processed foods, but when you actually go to school lunch and try and decide, okay, well can I feed this to kids or not? Is it highly processed or not? It's really not clear. And then of course, they created a new visual for the public. They've gone back to the pyramid. The plate was from the Obama era and we all know how the current administration feels about the

Obama's. And you can see the food pyramid here. It's upside down. A lot of you will say. It was actually upside down before and we just write it in. For those of you who haven't seen the new pyramid, it is sort of a headscratcher. It is indeed what most people would consider upside down. The smallest piece, the pinnacle,

is at the bottom. And that's also the part where the whole grains live. Based on basically all

nutrition science today, whole grains should be a major part of people's diets, but onward. At the top, at the widest part, which tells me you're supposed to eat the most of it, there's a whole chicken, a giant steak, a major hunk of cheese, a head of broccoli, and a bunch of carrots. In the middle, there's a block of butter, a couple of disturbingly large shrimp, an avocado, two walnuts, and an almond, etc. Kevin was as confused as we were.

We have all the animal foods, like super sized, huge portions, and then like a couple single types of nuts and a little thing of beans on top of white rice, which you're not supposed to eat per their guidelines on the whole grains. Like it just becomes like the picture doesn't convey what the text says. The science behind the new recommendations is out of whack, and the new image for our ideal diet is out of whack. But then the big question is, how much will either

“have an impact on what people are actually eating? I think for average consumer, they might be like,”

they're going to interpret it. However, they're going to interpret it. I think most people are going to be like, well, like red meat is back on the table. Home milk is back on the table, and probably clear that 10% sat-fat guidance. In other words, it's not going to help people eat more healthily, and it will just add to the existing confusion about what is healthy. Where it is going to cause issues is for people who have to follow the guidelines. That's like food providers

and prisons on the battlefield and schools. Kevin expects everyone trying to create the meals to meet these new guidelines to struggle with them. The other place Kevin says dietary guidelines

really make a difference is when it comes to how food is advertised. This has always been the case.

When the first dietary goals came out in the late 1970s saying eat less fat, it was really the food industry that took note. So everything got labeled as low-fact, and low-fat was implied to sort of a wink wink. It's good for you, and you saw reformulations of products that snack well. So they're impact on the diet is at a population scale as arguably probably minimal compared to what the marketing of the industry around them. To be fair, the guidelines from the government

aren't the only message that people are getting about what to eat. Low-fat diets were trending at the time that had to do with a lot of things in the culture, not just government recommendations, and the protein trends started long before the government recommendations this past January. But so having the government weigh in on it that people should eat more protein, it might make people eat more meat, but mostly it'll just give industry more fodder to

advertise protein everything. Start by going all in on protein. New protein lattes and protein cold foam. The one new announcement from Blue Bell, ice cream is already stirring up a lot of buzz on my, even between us right now. The company said it's launching Blue Bell Pro. It's a new line of high protein frozen dairy dessert. 15 grams of protein, no sugar, and it tastes great. Protein to a refreshing delicious protein water move. How is this possible? I mean, if washing your

protein supplemented ice cream down with protein supplemented water or a protein supplemented

protein numbers can be, and sometimes are artificially inflated by including collagen as a form of

protein, despite the fact that our bodies don't treat collagen as protein when we eat it. But details like that are not going to stop the food industry from caching in on government endorsed protein mania. At this point, you might be thinking, why do we even have these government recommendations given all the politics and the challenging science in the way they're used and abused? But they are actually important. School systems do need some kind of guidance for what to feed their

students, for example. Kevin says overall, they're a good thing. Just they've all these different

“uses, and I think there's, you know, at a high level when you look at it, we don't have very”

many nutritional deficiencies, at least as far as we can tell with them the population. It's not

like frank nutrient of this. We can argue about like people have suboptimal intakes, particularly when it relates to chronic disease. But the DRI framework, I think is generally considered mostly successful. Even assembling the research to update the DRI is important because it helps show where the gaps still are. For example, there are nutrients that scientists know we need, but they still don't know how much. That's important basic information about human health. So that's research

we need to fund and do. But even though they're useful on a larger scale, these numbers can't serve as a literal guide for every single person who reads a label. You can't look at a glass of orange juice from a container and say, oh, I've had this much vitamin C. I need this much more by the end of the day. They're not meant to be specific to each individual like that. They also have pretty much zero effect on the food supply. What's available in what it costs? So expecting

them to single-handedly change people's diets is unrealistic. Also, the guidelines are part of the general ether out there. All the science and all the things in the culture and all the trends, all of which is contributing to what people think they should be eating.

“Yeah, I think this is something I always try to re-center people on. Like I even”

10 years ago, I used to joke like the dietary guidelines can say whatever they want. Like the next Netflix documentary that comes out is still going to influence consumer behavior probably more than the DGA as well. As we've said though, the whole process does have value. It is still important putting a number on the nutrients we need, especially. That does matter. It's worth doing, but it's also sort of misleading because it makes it seem fixed and certain. And like if we only

hit that number, then we will somehow have achieved perfect health. Anna says that's the eternal paradox of the RDAs. This idea that you can quantify everything. Even though the people who are doing the quantifying know that there's so many variables at play, it's not actually possible to come up with a single standard that's going to work for everyone. That your own dietary history, your metabolism, your individual needs, all of that is going to change what your particular

“requirements are. But also this idea, I think, that permeates this that we could get it right in”

the sense of we can create optimal nutrition for everyone. And I think because in part it's so hard to measure what that means, there's this constant hope that new sort of heights of human potential will be unlocked if only and then whatever it is. If only we had adequate vitamins or if everyone was eating according to the RDAs. And so I think there's also that temptation that that's is really

part of this project and part of the fact that that optimum nutrition can never really be

measured. It's always, it's always sort of out there. Thanks this episode to Kevin Cloud and Hannah LeBlanc. We'll have links to their research on our website, gastropod.com. And for our special supporters, we'll have a newsletter filled with the visuals of what the ideal diet should look like over time and from around the world. Plus, what's up with collagen? You can get that newsletter and help keep the show on the air by signing

up to support the show at gastropod.com/support. Thanks as always to all our supporters and also to our awesome producer, Claudia Guide. Till next time.