Why Eating Well is Simpler Than You Think

Airdate: Tuesday, November 3, 2026 at 10 am

Figuring out what to eat can feel more complicated than ever. Are eggs healthy, or not? Is everything labeled ultra-processed bad for us? How much protein is enough protein? Stanford nutrition scientist Christopher Gardner says eating well is easier than you might think and that there’s more agreement among researchers than the latest viral diet fads suggest. We talk to Gardner about what the evidence shows. His new book is “Food Sense.”

Guests:

Dr. Christopher Gardner, professor and director of nutrition studies, Stanford University; author, “Food Sense: What to Eat and Why”

Episode Transcript

This is a computer-generated transcript. While our team has reviewed it, there may be errors.

Mina Kim: Welcome to Forum. I’m Mina Kim. Stanford nutrition scientist Christopher Gardner says our heads are spinning from all the “eat this, not that” advice we’re getting, which always seems to be changing. But Gardner has found, by comparing the most popular diets, from low-fat vegan to keto, that there’s more agreement about the foods to include and avoid in our diets than you might think. In his new book, Food Sense, Gardner shares where there is scientific consensus and debunks myths about everything from seed oils to protein intake that can overcomplicate our choices. What’s a question about the foods you consume that you want to put to Christopher Gardner, who joins me now? Welcome to Forum, Dr. Gardner.

Dr. Christopher Gardner: Thanks for having me. That was a great summary right there. We’re set.

Mina Kim: Thanks. Well, why do you think our heads are spinning? Why do you think it’s gotten more complicated than ever to figure out what to eat?

Dr. Christopher Gardner: A combination of capitalism and social media and hawking and selling stuff. So when you hear stuff that makes your head spin, follow the money and see if the influencer is selling something.

Mina Kim: Yeah, so we’re getting a lot of information from a lot of different sources, from people with a lot of different motives, it sounds like. Well, you authored a paper that sort of simplified this. It was for the American Heart Association that compared a number of different diets and found that there was consensus in some areas. So which diets did you compare, and what did you find?

Dr. Christopher Gardner: This was such a fun assignment, and actually I’ve described this before, and I’d love to open with a caveat or qualifier. So one way to think of different diets would be the Asian diet, the Mediterranean diet, the Latin American, Indian, African. The American Heart Association updated their dietary guidance in 2021, and interestingly, after doing that, coming up with 10 basic domains to follow, they got a lot of feedback from the public saying, “What about the popular diets? How about the paleo, keto, carnivore, vegan? How many of those align with your 10 domains?”

And so at the time, I was the chair of the American Heart Association’s nutrition committee, and one of the main purposes they serve is to write papers that are science advisories to help inform the public on things they’re confused about. And I just leapt on this opportunity, found nine others that wanted to help.

And, Mina, a really fun part was defining how many popular diets there are, how many are similar, and could we categorize them so there aren’t a million? And we actually came up with about 10 categories. Some of the popular diets kind of fit into one. I’ll give you one example. There’s a very strong contingent of low-fat vegans out there. It’s the Ornish diet, the McDougall diet, the McGregor diet. A bunch of those, and then there are different low-fat diets out there, glycemic load.

So part of it was actually running through research papers and seeing how people were defining these when they wrote research papers about them and assigned study participants to them to study them.

And I’ll pause for a minute and have you think about this. So if we looked at two different Mediterranean diet studies, one dinged dairy, and one said dairy’s okay as long as you have yogurt. So if you can imagine, there are a couple of subtle differences. Not all Mediterranean is the same. Not all paleo is the same. People follow the ketogenic diet in very different ways. Some of them are very inappropriate. We can get to that if you want.

But that was stage one. Like, how many categories? Ten. How do you define them? Well, and here’s a really important point I hope the listeners will appreciate.

I feel like when somebody thinks of the Mediterranean diet, they just think of olive oil as the main component. And they think, “Great, I can have eggs for breakfast and a Big Mac for lunch and a Whopper for dinner. I’ll just keep a jigger of olive oil by my nightstand. If I chug that at night, I’m Mediterranean.”

Or, “I’m vegan, and so I had my Oreos, my French fries, and my Coke today,” which technically are all vegan.

But what we approached was, what would be an optimal vegan, Mediterranean, keto, paleo? If you had a proponent of them in the room with you, what would they say is the best of that type of diet?

And so we had 10 different categories, and we had 10 domains of American Heart Association guidance. It had to do with whole grains and fruits and veggies, things to include, healthy oils. It had things to avoid: added sugar, processed food.

Yeah, I was stunned after doing this little exercise. We made a heat map, sort of green if these cells align and red if they don’t, and yellow if they’re in the middle. And five things really stuck out. And so, veggies for all of them, whole foods for all of them, get rid of added sugar and refined grains and processed food for all of them.

And those would be kind of boring if everybody heard that and said, “Yeah, I know that, and we all do that.” America doesn’t eat much sugar or processed food or refined grain, and they love their whole foods and their veggies. But they don’t!

And so the fun thing for me was like, “Oh my God, why are we bickering about the fringes of chia seeds, or the soy phytoestrogens, or the lectins in beans, when, in fact, if you had proponents of all the different categories with you and you said, ‘Could we all first discuss what we agree on?’”

That America or the world already doesn’t do. Could we have a kumbaya moment here and say there really is a lot that we agree on?

And that felt really empowering to start from that perspective instead of starting from a bickering, superfood perspective.

Mina Kim: Yeah, so you call those the big four: to include veggies and whole foods and to limit or avoid added sugars and refined grains, as ones where all these different diets overlapped. You also have something called the solid six. What is the solid six?

Dr. Christopher Gardner: Okay, so it’s kind of impossible to get everybody to agree on everything when these diets are so different. So I’ll name them quick, and then I’ll run through a quick explanation. It would be beans, fruits, nuts, eggs, fish, and yogurt.

So let’s start off with what they are and how come somebody disagrees.

So for the beans category, and technically, Mina, I hope the listeners will appreciate this. I don’t know if you want to do this later, but the correct term is legumes. But Americans don’t know what the heck legumes are. And so we tend to say beans, peas, and lentils. So let’s just stick with beans for now.

There’s a guy out there named Gundry who said, “Oh my God, plant paradox. Beans have lectins. Lectins are antinutrients. They grab and drag out nutrients, and you poop them out after you’ve eaten them. So this is anti-nutrition. Avoid beans so that you can avoid the lectins.”

Well, it’s really pretty easy to boil or soak your beans and get rid of a lot of the lectins. And beans have an amazing number of great things. They have fabulous fiber. They’re actually the highest plant source of protein. Beans are completely underappreciated and underconsumed in the U.S.

So if you go to almost any health professional, except some of these lectin avoiders, beans are in. That would be total solid six. Look around the world, and hopefully we’ll talk about that later. Mediterranean, African, Latin American, Indian. Oh, Indonesian peanut sauce on gado-gado. Wow.

Next would be fruits. So we have a lot of people with diabetes or prediabetes, and we have very, very, very low-carb diet fanatics who really want you to get rid of carbs. And if you have any, maybe it would be a raspberry or a berry or an above-ground vegetable. But fruits, wow, aren’t fruits really sweet, and don’t they have a lot of sugar? That would probably be the biggest problem for people trying to control their blood glucose. And so they’re thinking, “Wow, do I also have to avoid fresh fruit?”

And I think for a quick answer to that, you can go to the American Diabetes Association website and look up fruits, and they promote fruits every day. They just point out it should be a whole fruit. It shouldn’t be orange juice. It shouldn’t be any kind of fruit juice. You should be eating the whole apple, the whole fruit, the whole mango, the whole pear, whatever it is.

And it comes in a food matrix. When you’re eating the natural sugars in fruit, that delays the time it takes to get that digested and absorbed. And the key there for the people who are trying to control their blood sugar is the speed at which the glucose that you’re eating ends up in your bloodstream. Real whole fruit is really fine.

The next category would be nuts. Nuts have a lot of good protein and fiber and fat. Nuts are a great source of fat, but it’s the unsaturated fat kind. We have decades and decades of data to show that unsaturated fat, replacing saturated fat, helps to lower LDL cholesterol.

And, oh my God, there’s such variety: pecans, walnuts, cashews, peanuts, which are really inexpensive. So if you add nuts to a salad, if you add nut butter to a banana for a quick snack, there are so many great ways to have nuts, and huge, widespread consensus that nuts are great for us.

Yes, they’re kind of concentrated calories, so you don’t want to have too many of them, and you don’t want to be at the bar eating a bunch of salted nuts that make you thirsty for more beer. But as a whole, the nut butters, the nuts that you could put on your oats in the morning, huge consensus on that, except for the really low-fat vegans and some of the people that are just completely anti-fat.

The next one would be eggs. And maybe we’ll get into what and why later. I hope that’s one of my favorite things in the book to talk about. But eggs are, yes, full of cholesterol. And we have huge rates of heart disease, very high rates of heart disease in the U.S.

And, in fact, when the arteries in your heart get clogged, it was cholesterol that was carried around in the blood in an LDL particle that likely contributed to that blockage of the artery and the cholesterol that got taken up into the artery wall.

But a funny thing about metabolism is when we eat cholesterol from an egg, let’s say, or a shellfish, those are two particularly interesting examples. Neither eggs nor shellfish have a lot of saturated fat, but they both have a lot of cholesterol.

And when we have a meal that has either of those, before it goes anywhere else, the cholesterol goes to our liver. Our liver happens to be an organ in the body that makes more cholesterol than any other cell or organ in the body.

And, in fact, we need cholesterol for all kinds of things. It’s in cell membranes. We make sex hormones out of it. There’s really a lot of uses for cholesterol, but you don’t have to eat any because our body makes it naturally. In fact, the liver makes a lot.

But because the liver captures everything that you just ate and digested and absorbed first before it goes anywhere else, the liver adjusts and says, “Oh, look how much I got in the diet.”

Mina Kim: So it’s really the combination of high cholesterol and high saturated fat that you should be on the lookout for. But the cholesterol, as you’re saying, that exists in eggs and shellfish, not so much.

We’re talking with Christopher Gardner about just the ways that diets actually agree with each other on what tend to be the best things for you to simplify your efforts to eat healthy. And we’ll have more with him and you, listeners, after the break. Stay with us.

If you’re listening to Forum, I’m Mina Kim.

With so many diets out there claiming to be the most healthy that also seem to be so different, it can be hard to figure out what to eat. But Dr. Christopher Gardner has looked at the most popular ones, or the most popular categories of diets, and figured out that they all say include veggies and whole foods, limit sugars and refined grains, and that a lot of them say, not all, but that good things to eat are beans, fruits, nuts, eggs, fish, and yogurt. And he’s explaining why.

And listeners, what questions do you have for Dr. Gardner about how to eat well? Are there specific foods that you have questions about? Is there a particular diet you’ve tried and had to abandon, or one that you swear by?

You can tell us by emailing [email protected], finding us on Discord, Bluesky, Facebook, or Instagram at KQED Forum, or by calling 866-733-6786. 866-733-6786.

I think you’re sort of answering this listener’s question in San Francisco, who says, “I’ve been mostly a vegetarian for 20 years, but all of the changes, even within vegetarianism over the years, are so confusing. High protein, more vegetables, better fats. What’s the right combo? What are the basics for a healthy non-meat diet?”

And you are going through some of these, the solid six. You finished at eggs before the break. We’re on fish, and yogurt is next. Do you want to take those, Christopher?

Dr. Christopher Gardner: Yeah, absolutely. So for the vegetarians and vegans out there, right, you can pick the healthiest and the least healthy veggies, fruits, everything, including animal foods. And so eggs and fish and yogurt are better than hamburgers and bacon and things like that.

So for people who don’t want to go totally vegan or don’t want to be a vegetarian at every meal, it’s a continuum.

So one of the six things on my list for almost total consensus is also fish. And a funny comment I often get from vegetarians is, “What is it that you don’t eat?” “Well, I don’t eat fish.” “Why?” “It has a face.” That’s how I define what I eat. Fish have faces.

But the data are pretty strong that fish is pretty good, especially if it’s instead of something else, instead of a hamburger, instead of bacon.

The same would have applied to eggs, where so many Americans eat sugary breakfast cereals with multicolored marshmallows, and honestly, scrambled eggs would be so much better than all that sugar and refined grain.

So I think eggs and fish have pretty broad consensus. And the last one on that list was yogurt.

So, to be honest, dairy’s a really simple one to talk about. Three-quarters of the world is lactose intolerant. There isn’t any need for dairy. No one ever dies of dairy deficiency disease. There isn’t any such thing.

But as we all know, dairy can be milk. It can be butter, it can be ice cream, it can be lots of different things, and it can also be yogurt.

One of the things at Stanford I’ve been studying with Justin and Erica Sonnenburg for the last decade is the microbiome. And a hot topic for the microbiome is eating fermented foods. Yogurt is a fermented food.

Problem is, if you go to the grocery store, Mina, I don’t know about yours, but mine has about 20 rows of blueberry, raspberry, peach, blueberry, raspberry, peach. And when you look, they’re low-fat, organic, full of sugar. They’re like little sugar delivery systems.

So if it was just a plain yogurt that you added your own fruit and nuts to, that’d be a great choice for a lot of people, too.

So those are the six that I actually think there’s pretty strong consensus on, even across some of the groups that disagree with one another.

Mina Kim: So if people want to incorporate more of the six into their diet, like you said, we don’t eat nearly enough beans, and Discord user Chaz writes, “Beans! Let’s talk about beans.”

So if you want to incorporate more things into your diet, what have you found are the keys to motivation and to making those changes last?

Dr. Christopher Gardner: Okay, I got two categories, and one you have been mentioning in your promo for this, and it’s taste and pleasure.

So much of the nutrition community has been, “Avoid that, have this cardboard. This cardboard is great, it has a lot of fiber, it’ll lower your cholesterol. I know you really wanted the great-tasting thing, but please suffer and please restrict.”

So, you know, one of the proudest things in my life for the last decade has been taking on, as a scientific advisor for the CIA. And I bet a lot of your listeners have figured out that’s not the Pentagon. That is the Culinary Institute of America. And a satellite is right up north of us in San Francisco. There’s one in Napa, there’s one at St. Helena.

And the craft of chefs is to make everything taste delicious. And one of my favorite CIA members, Greg Drescher, has framed it as “unapologetic deliciousness.” Chefs can make it unapologetically delicious.

And when I work with them, in my back pocket, I have health and environmental sustainability. But don’t lead with that. Don’t shame people. Don’t push them. Say, “Oh, wouldn’t you like this amazing Asian stir-fry that is full of tofu, tempeh, edamame, and some vegetable oils, even seed oils?”

Or how about this Mediterranean hummus? How about this Indonesian gado-gado, this amazing peanut sauce over vegetables? How about in Ghana, they have a red red, which is a cowpea dish, which is that really traditional dish there?

And think of all the Latin American dishes that are bean- and rice-based. If you look around the world, beans are a staple everywhere.

And can I do a little legume rant? I’m sure Chaz would appreciate it.

Okay, so technically, I want everybody listening to think about raising your hand. How many times have you used, I’ll just direct it to you, Mina, have you used the word “legume” in a sentence in the last week or month?

Mina Kim: Probably not in the last week.

Dr. Christopher Gardner: Okay. How about the term “pulses”? Not the, not for beans, not blood pressure pulse, right?

Okay, so here’s a really interesting thing, which is I worked on the Dietary Guidelines Advisory Committee from 2023 to 2024, and we found a whole lot of data on the benefits of the family of legumes, but it includes a lot of different things.

And as we were writing this up, one study was chickpeas and one study was lentils and one studied soy. Having a really hard time wording it.

And then we decided, “Ah, according to the botanical hierarchy, legumes covers all of that. Why don’t we just say legumes?”

And it was really funny because the USDA communication team got back to us and said, “You’re gonna have to say beans, peas, and lentils.”

We said, “Why? Legume is actually the correct choice.”

And they said, “Oh, if you were in another country, you could do that. But here in America, you would have Americans going and saying, ‘Look, I found the chickpeas, I found the lentils, I found the soybeans, and I found the peanuts, but I cannot find the legumes anywhere. They’re not labeled.’”

And so the truth is, legumes are fresh peas and beans and peanuts and any kind of soy. That includes tempeh, tofu, soy milk, edamame. And pulses, and pulses is more common in the South Asian population, but that would be lentils and chickpeas and dried peas and dried beans.

And there is an amazing farmer up in Napa, Rancho Gordo, that dries beans and has a huge variety to help you find out this. And they have some amazing swag that is so fun.

So I want to encourage everybody to not only try the beans, but to join the Leguminati, because the Leguminati are the intelligent people who have seen the fabulous benefits of legumes.

Really, no saturated fat or super low, lots of fiber, lots of protein. You can fiber-max and protein-max at the same time with these beans. And globally, they’re inexpensive, they are versatile, there are so many different beautiful kinds of legumes. They’re really underappreciated.

So I’m gonna give everybody a shout-out. Go try some different legumes in the cultural diet of your choice.

Mina Kim: And you were saying that, you know, for us to try to stick with these things, one of the things is to really try to make them pleasurable, right? Because that’s what guides our food choices.

You said there was another category, though, and I just wanted to ask you if you could finish up with that.

Dr. Christopher Gardner: Thank you for listening. Okay, and this is my favorite.

So I’ve been vegetarian slash vegan for 43 years. And are you ready for my motivation? I got dumped by a girl who was a vegetarian. I really just wanted the girlfriend back. So I became vegetarian. Didn’t work. She didn’t take me back, but I liked being a vegetarian.

And then, kind of by mistake, I got a PhD in nutrition science. I had wanted to start a vegetarian restaurant. I never did. Got the PhD, got a faculty position at Stanford, and learned, wow, it’s super healthy for you to eat a lot more plants in a plant-rich diet.

And then I remembered in college, I was actually a philosophy major in college, and that was all about the ethics of animal rights and welfare. And so it hits that.

And then, in addition to that, Stanford now has a new School of Sustainability. And we look at a plant-rich diet. It actually does a lot, a lot of benefits for greenhouse gases, land use, water use, nutrition from nitrogen and phosphorus runoff.

And so I teach a class at Stanford that changed my career, and it’s called Food and Society. And in this class, we never talk about health. We never talk about the Krebs cycle or that the mitochondria is the powerhouse of the cell. We talk about animal rights or the environment or drought or religion or culture or any of these things.

And what I find is the students in that class are so much more engaged than the students in my Nutrition 101 class, where I do carbs, fats, proteins, vitamins, minerals, because they’re sort of personal identity issues. They’re value issues.

And I also find that the students don’t all latch onto just one. Some of them are more into the environment. Some of them are more into environmental issues. Some of them are more into human rights issues in the labor force of the folks who work in slaughterhouses, a really dangerous, low-paying job in the meatpacking industry or in fast-food restaurants.

And so part of that second motivation to make and keep a change is to recognize that you could kind of tailor that to match your personal values.

And then when it comes time to have the cookie or the steak or the Mediterranean salad, one person would say, “Oh, I’m going to do better tomorrow,” because the only one it’s impacting is me.

If you look at all these others, you say, “No, actually, it isn’t just me. When I make this choice, I’m having a societal and a global impact every single day with my choice.”

For a lot of students that I see at Stanford, that is a huge motivating factor to rethink your food choices and try to align them with your personal values.

Mina Kim: So that’s a way to channel them.

We’re also getting just some basic questions here about foods. This listener, Amber, writes, “Can you talk about artificial sweeteners? Healthy sodas are having a moment right now. My 13-year-old daughter especially likes Olipop sodas, but when I take a sip, I’m hit with this intense fake sugar taste. I hate it. What does the science say about using these sweeteners, and does replacing real sugar with these actually make these sodas healthy?”

Dr. Christopher Gardner: Yeah, yeah, yeah. It’s a great question, and I have to go back a while, but when I worked with the American Heart Association back in 2012, I was the lead author of one of those science advisories where we looked at artificial sweeteners and natural sweeteners, stevia, for example. There’s also a couple others that are a little more natural than false.

I’m just gonna start out and say you will never find any of those artificial sweeteners in a bell pepper or broccoli. Legumes. You will always find them in crap.

So you’ve got a soda, which is crap. It’s junk food. It’s full of sugar, and now you’ve swapped out and you have stevia or saccharin or sucralose. Is it a healthier soda because you don’t have the sugar? It’s probably healthier, but it’s not healthy. You should be drinking water.

How about if you’re putting it into cookies or snacks or some of the bars that we have, the ones that say “no sugar” on them? Yeah, if you look at the rest of the ingredients, they’re not really very healthy ingredients.

So is that bar a little healthier because it doesn’t have the sugar? It’s a little healthier, but it’s not a health food.

When we were writing this report, Mina, we almost threw our hands up and said, “We really can’t find very good, strong evidence that the artificial sweeteners are that much better than sugar.”

And a clinician that we were working with said, “Look, I am dealing with this man who’s overweight and he’s diabetic, and he has been drinking a 64-ounce Big Gulp every single day, not realizing how many calories or sugars are in there. And I got him off the full-sugar soda and I got him on diet soda. His blood glucose is down, his weight is coming down. If you publish this thing and say, ‘Meh, not much difference,’ he’s gonna look me in the eye and say, ‘Doc, how come you had me make this switch? I’m gonna go back to my 64-ounce Big Gulp.’”

Boy, did I feel for that clinician who was working with somebody who was getting some benefit out of that switch.

Now, that might’ve been a more extreme case, but circling back, you know, is this an excuse to have a cookie or an excuse to have a snack because it doesn’t have sugar? It’s a pretty weak excuse. It’s not healthy. It could be healthier, but it’s really not healthy.

If you want to eat healthy, you should avoid all the artificial sweeteners and all the sweeteners. But what if it’s a celebration? What if it is a special day? What if something happened? Go ahead and have a cookie. Just don’t have the whole sleeve of cookies, or have a small piece of cake. Don’t have three pieces of cake! Have a little sugar now and then. Have some pleasure, have some joy. Participate in celebrations, don’t avoid them. Just use a little common sense and restraint.

Mina Kim: What about ultra-processed foods, though? They’ve been really maligned. Are those things that we should try to avoid altogether?

Dr. Christopher Gardner: Oh, and I love this. I actually wrote with Maya Vadiveloo another American Heart Association science advisory on this. And the conclusion was, yeah, you know, almost all the things that are ultra-processed we’ve always called junk.

So please pull me out of the rabbit hole if I go too deep on this. But the things that we want people to eat are vitamins and minerals and fiber, and the things we want them to avoid are the added sodium, added sugar, refined grain that’s pretty characteristic of all the junk foods.

There’s a guy in Brazil named Carlos Monteiro, and he observed something really interesting that I do, I totally appreciate this. He said, beyond the sugar and the sodium and the refined grain, a lot of the foods out there have weird colors and weird flavors and weird dyes and emulsifiers.

And he actually gave this whole category of food ingredients an interesting name. He called them cosmetic additives. And he’s the one who really invented this name, ultra-processed foods. It’s also called, in the academic world, the NOVA classification.

Classification one is totally not processed, and then two is some cooking things, and some three is cooking things that are minimally processed and are a little bit processed.

And then his point is that there’s this obscene point when you’ve crossed the line, kind of like pornography. What’s the difference between pornography and art? “Ah, that’s art. That is art.” “Oh no, that has crossed the lines. That is not really art. That’s pornography.”

That’s kind of what food porn is. “Oh, you were doing this to make a nice recipe, to make it delicious, to make it look good. Oh my God, now look what you’ve added to it. It’s a monster, and it has all these cosmetic additives.”

Mina Kim: So that’s really what he meant when he was talking about ultra-processed, where these cosmetic additives come in. Because one of the things that I appreciated in your book is that, for example, there are things that are very processed, meaning that they’ve been cut or chopped or powdered or whatever, right? That actually don’t change the quality of the food itself, and we could give some ultra-processed foods a break, like oats, for example.

Dr. Christopher Gardner: I’m so glad you said oats. That’s my favorite example.

So, Mina, for a long time I’ve been eating steel-cut oats a couple times a week for breakfast, and my father-in-law gave me a hard time. And he said, “Why are you eating that processed food?”

And I said, “What do you mean? I’m eating steel-cut oats, man. I’m all-natural.”

And he said, “Why aren’t you eating groats?”

I said, “Groats? I don’t even use that term.”

And he says, “Yeah, that’s the term for the whole kernel of oats.”

And I have a really nice grocery store next to me that does not have groats. It has steel-cut oats. And I went to the hippie store and I got groats in bulk, and now I have whole-kernel oats twice a week.

Oh, I hear the music, so I think it’s time for a break.

Mina Kim: Right, but it sounds like one of the things I was struck by is that even quick oats, right, have the same nutritional value. I don’t know, as much as groats, but maybe as much as steel-cut oats, and also even the fiber, which was sort of reassuring to hear because I can’t always wait for my steel-cut oats. You know what I mean?

Dr. Christopher Gardner: So pick it up later. We go from groats to steel-cut oats, to rolled oats that take an hour to cook, to quick oats that take minutes to cook, to oat flour. Can we go back to that continuum after the break?

Mina Kim: Right after the break. But, yes, I also want to get to the calls and comments that we have as well. So stay with us, listeners. This is Forum. I’m Mina Kim.

You’re listening to Forum, and we’re talking with Christopher Gardner, nutrition scientist and professor of medicine at Stanford University and author of the new book, Food Sense: What to Eat and Why.

He’s talking about why eating healthy is easier than you think, that there’s scientific consensus across a range of different diets. So we can give ourselves a break in some categories.

Including, we were just talking about before the break, Christopher, really quickly, if you want to, can you just let me know what you said about that last category of oats? Maybe even powdered oats are also not terrible, even if they’ve been quite processed?

Dr. Christopher Gardner: Well, here’s the thing. It’s actually worse than the delivery of glucose to your bloodstream, which is much faster than the groats or the steel-cut oats or the rolled oats. But none of those actually classify as ultra-processed because there’s only one ingredient in it. There’s no artificial colors. There’s no artificial flavors. There’s none of the emulsifiers. It’s all just oats.

So if you go the other direction, you say, “What about Cheerios? Isn’t that a cool breakfast cereal?” Cheerios, to be honest, is not bad. But there are now cookies-and-cream, high-protein Cheerios, and that is ultra-processed. That has crossed the line. It has artificial stuff in it.

And so it’s not the oats or the oat flour. The things that get called ultra-processed have to have these cosmetic additives.

Which is why, when we wrote this scientific advisory from the American Heart Association, we said it might be helpful to use the term ultra-processed, but, to be honest, there’s a couple of exceptions on both ends. And really, America, it’s just that you eat so much crap. Call it crap, call it junk food, call it ultra-processed. I don’t really care. I don’t really think this new name is gonna help all that much.

In fact, it is gonna make it hard for food service directors at schools who’ve been told to get all the ultra-processed food out of their school lunch, which is hard because it’s ubiquitous in our culture.

Mina Kim: Well, let’s start David from Dexter, Michigan, I think, wants to know about the benefits of not eating. David, go ahead. You’re on.

David: Yes, there seems to be a lot of confusion around fasting and one meal a day. Have there been any new studies on the effectiveness of fasting and maybe one meal a day?

Dr. Christopher Gardner: Oh, well, it’s a great question. I think really what you’re bringing up, David, is how many different names there are to this intermittent fasting.

Okay, so sorry, I’ll try to do this super fast. But one is Valter Longo has this thing where you fast mostly, but not all day, for five days a month, and 25 days you eat regular. There’s another group who says, “Oh, twice a week I fast for the whole day,” or, “Once a week I fast for the whole day.” And for some of those, they actually have some food during that period.

The most common thing of intermittent fasting is time-restricted eating. So you eat within a 12-hour window or a 10-hour window or an eight-hour window.

And then, sorry to do this to you, but when you get to the eight-hour windows, there’s some people who say, “Oh, skip breakfast and start at noon. You can eat from noon to eight.” And there’s others who swear by, “Oh no, I eat at eight in the morning and I stop eating at four in the afternoon.”

And so the problem, because I’m a scientist here, the problem is there’s so many definitions of fasting that it’s actually pretty hard to test.

And, David, in a scientific study, it’s also, unless you house people and videotape them the whole time, it’s hard to see over time how adherent they are. And that’s a really important part of nutrition science, to see if they were really following the rules.

And if this was for a week or a couple of weeks, it wouldn’t be as hard as saying, “Well, I’ve tried this diet for a year now, and it hasn’t worked.” Imagine me trying to follow that person around, or hundreds of those people, to make sure they’re really doing it.

I just want to toss out an expert in this. Krista Varady is the one who has done the most with fasting and intermittent fasting. So I suggest you look her up, but I’ll jump to her conclusion, which is intermittent fasting or this calorie restriction, whatever, however you want to frame this, works compared to nothing.

If you try any of these forms of intermittent fasting, they will work compared to doing nothing. But if you compare them to any of the traditional things like calorie counting or low-carb or low-fat, it usually ends up being a wash.

And the important thing here is low-carb doesn’t work for some people. Low-fat doesn’t work for people. And that intermittent fasting, that restricted window, it does work for some people. It’s hard to show that if you randomly assigned them, it would work for the average person. But I don’t want to discount that it works for some people sometimes.

But the evidence isn’t really strong.

Initially, you were talking about fasting that’s… I think of the people who fast for religious reasons, for Ramadan and things like that. That’s a natural experiment that’s pretty fun, and I actually think the benefit of that is mostly spiritual and not metabolic.

Mina Kim: Thanks, David, for the call. Let me go to Anne in Redwood City next. Anne, go ahead. You’re on.

Anne: Hello, Mina and Dr. Gardner. Thank you for having this wonderful… My question is —

Mina Kim: Well, I think — oh, go ahead. We lost you for a second. Your question is what?

Anne: Hello. Yes, I’m an aficionado of Dr. Michael Greger, and I’m trying to eat fiber to get my cholesterol down so I don’t have to take a statin drug. The statins seem to make my muscles ache. Is there anything — is there such a thing as too much fiber? I get about 50 to 70 grams a day.

Dr. Christopher Gardner: Woohoo! All right, congrats! Well, it depends how much you fart, and it depends how much GI distress you get.

There’s a lot of people who don’t handle an increase, a rapid increase of fiber well, but usually your GI tract will adjust.

My favorite friends in the microbiome world, the Sonnenburgs, study the Hadza, a traditional hunter-gatherer tribe, and they eat more than 100 grams of fiber a day.

So for the people who complain that they can’t go from 20 to 30 because they fart too much, I think they need to go live with the Hadza for a while.

So the human body can adapt to a lot of fiber, but we’ve actually done a lot of fiber studies, and everybody has a very personalized response. For some people, it’s really uncomfortable.

And for some people with GI issues, not cholesterol issues, we have an amazing physician here at Stanford named Shawn Spencer. And he works with people who say, “Oh my God, I can really only eat chicken and white rice. That’s it. Otherwise I have all these GI issues.”

And he has them eating beans and veggies and fiber over time, working with them and experimenting with what works and doesn’t work.

So I’m super proud of you to get to 70 grams of fiber. If you tolerate it, there really shouldn’t be much of a downside.

At some point, and can I assume that you’re getting it from foods? Because if you’re getting it from supplements, then you’re going to be missing the nutrients that would have come with the whole grains or the vegetables or the bell peppers.

So if it’s foods, I think it would be hard to get too much fiber as long as you can tolerate it.

Mina Kim: Well, listener Maggie wants to know, how much does one’s diet need to change as we age? There’s so much popular information about the need for increased protein intake for perimenopausal and menopausal women. Do our diets really need to change significantly?

Dr. Christopher Gardner: So it’s interesting. When you look at our standard national recommendations, they actually are set for different age groups: pregnancy, lactation, young adulthood, older people. And most of the traditional nutrients, the vitamins and the minerals, don’t change much at all through the whole lifespan.

There’s a couple things. B12 is an issue. Um, vitamin D might be an issue. Protein comes up again and again.

Mina, that might be a huge rabbit hole to go down.

I think, so for people who are aging and getting older, sometimes our denture, our chewing, our, “Oh my God, we’re lonely, we’re depressed, we don’t really like food that much.” I’m a little concerned that they’re not getting enough calories, period.

But do they actually need more protein? I’ve seen some studies where older people get randomized to eating more protein or less. And a clever recent study also included going to the gym or just doing some simple resistance training with that.

And the key conclusion that came out was: use your muscles.

The extra protein that you’re getting isn’t nearly as important as using your muscles. You don’t have to be going to the gym as an older person and sweating and grunting, but some simple resistance training, going out for a walk, but not just cardiovascular. Using your arms and legs will help maintain the muscle that will keep you more mobile and vital as you get older.

So I would push that above the protein. Then if you wanna hedge your bet, go ahead and have some extra edamame.

Mina Kim: Yeah, actually, Christopher, I think the last time we had you on was because there is one diet fascination that just feels unmatched compared to others recently, and that is the fixation on protein.

And essentially, in that conversation, you were saying we’re probably getting enough protein. We are likely getting enough protein, and that there could even be downsides to getting too much, or we just don’t really know what the effects of that are.

Dr. Christopher Gardner: Yeah, and, Mina, there’s two things in one I’m going to dismiss pretty much for the most part.

So there’s no place to store extra protein if you’re trying to really make sure you had enough and you just had extra in case. At the end of the day, you can’t save it till tomorrow.

So you break it down. You actually turn it into carbohydrate. You have to break off the nitrogen component. Your liver turns it into ammonia. Your kidney has to excrete it.

For a long time, I thought, “Wow, all that ammonia excretion would be bad for your kidney.” And I have some nephrologist friends who say, “Wow, the human kidney is super resilient.” It actually, as long as you have a healthy kidney, it won’t really be adversely affected by too much protein.

But if you have impaired kidney function, one of the first things they tell you to do is not eat so much protein so it doesn’t exacerbate what’s going on.

What we’ve really found in the nutrition world is that the main adverse impact of the extra protein is you did it by eating meat. You didn’t get as much fiber. You got more saturated fat.

And because you’re eating more meat and more protein, more protein bars, more protein Pop-Tarts, more protein David bars, you didn’t eat as many legumes or veggies or grains or fruits that had all the other nutrients that you can’t get from the primary protein sources.

So a balanced diet gets thrown out of whack when you overdo the protein obsession, which many Americans are currently doing.

Mina Kim: Well, not only are many Americans — first, let me remind listeners, you are listening to Forum. I’m Mina Kim.

Not only are there many Americans currently overdoing it, but how should we treat the U.S. dietary guidelines, the inverted food pyramid that RFK Jr. has come out with that has made protein such a huge part of it?

Dr. Christopher Gardner: Oh, you touched a sore spot.

So again, rein me back in if I go down a rabbit hole. But, Mina, I was selected as one of 20 scientists who, every five years, when they get ready to update the guidelines, pick a scientific team to go back and look at the new evidence in the last five years. Is there anything that really suggests we should update our guidelines?

And 20 of us volunteered to do this for 10 hours a week for two years. So we basically each put in 1,000 hours over two years, handed in a 420-page report. It had a 1,000-page supplement with all the extra facts in it.

And we turned it over in November of 2024, or December technically, just as the administration had turned over. And we turned it over to RFK Jr., the head of Health and Human Services.

And he immediately tossed it in the garbage can and said, “We’re not gonna use this. You guys are too conflicted, and you used a health-equity lens, which we think is super inappropriate here at HHS.”

Which is really horrifying to think that a health-equity lens is an inappropriate way to do science, because they are supposed to be the dietary guidelines for all Americans, not just well-off white Americans.

And they replaced the two years of work that our group had volunteered to do in good faith and put in a panel of nine people. They gave them less time, there was less transparency, and what they produced quite quickly was an upside-down food pyramid with a big steak in the upper-left-hand corner, which was where most people’s eyes are drawn because we read from top to bottom and left to right.

And quite a few of us were either sad or horrified or really mad. I’m in the really mad category that I put in 1,000 hours, and it got tossed for this.

Now, many of the dietary guidelines are fine, carried over from past years. But one of them is on this protein issue: prioritize protein at every meal.

That is one of the ones that has most of the health professionals scratching our heads because protein has never been a nutrient of concern.

Every time the dietary guidance come out, they name the top four or five nutrients that we should get and the top four or five that we should exclude.

Protein has never been a nutrient of concern. Fiber is, calcium is, vitamin D is, iron is sometimes, but not protein.

So we’re upset about the dietary guidelines.

Mina Kim: We have just a few minutes left, but Trish in Richmond is asking, because Trish agrees with you and wants to get protein from beans, for example. Trish writes, “Can your guest comment on the high amount of carbs in legumes? My understanding is that high carbs are not good for blood sugar.”

Dr. Christopher Gardner: Yes, and people are really abusing those continuous glucose monitors that you slap on your abdomen or your arm.

So as long as you’re getting fiber and whole foods with those carbs, there really isn’t any reason to avoid them. The fiber-rich carbs, which legumes clearly are, are good for you.

I ran a classic study a decade ago with 600 people, low-fat versus low-carb. And the low-fatters ate as many beans as they could.

Interestingly, on any diet, even when you do it well, some people do better and some people do worse.

So when the low-fat was combined with, compared to the low-carb, the low-carbers had fewer beans and fewer grains. And some of them did great. They had avocado fat. They had fish fat. They had nuts and seeds, some of which are legumes.

So you don’t have to eat a lot of carbs. It’s just that Americans hardly eat any legumes, so go ahead and have those beans on a fantastic salad smothered with nuts and olive oil and avocado.

You could actually make a pretty high-fat Mediterranean salad that way and get carbs from the beans, but maybe not overdo the carbs. That would be a way to personalize it for yourself.

Mina Kim: Well, Cessna in San Francisco writes, “Are we spending too much time thinking about the perfect diet? People stayed relatively fit and healthy without this much obsession a century ago.”

We just have two minutes left, but in your book, Food Sense, you include some of your favorite recipes. And I’m wondering if you can leave us with one that might be good if people are feeling stressed today or to calm any Election Day jitters, maybe.

Dr. Christopher Gardner: Sure, sure, sure. Oh, yeah. So some of my favorites are a tofu scramble for breakfast in the morning, and a staple of mine is a salad.

I just — everything I just said about that salad is sort of in the recipe. I make a really fun wheat berry salad, that is the whole wheat kernel, not wheat flavor or chopped-up wheat or things like that.

And maybe gypsy soup. Okay, so it’s actually not called gypsy soup. It’s called something else in the book. But it’s a very sort of Persian-Mediterranean dish. It’s got sweet potatoes in it, it’s got onions, it’s got turmeric and cumin and coriander and cinnamon and basil.

And it’s a super warm, great fall soup. It’s modified from Molly Katzen’s gypsy soup from the Moosewood Cookbook years ago.

If you want some comfort food on Election Day, either get the book really quick and look at the soup recipe, or just Google “Moosewood Molly Katzen Gypsy Soup,” and that’s one of the main sources for that soup. That would probably serve you well today so that you can vote, relax, and wait to see what happens. Fingers crossed.

Mina Kim: We’re talking with Christopher Gardner, nutrition scientist and professor of medicine at Stanford University, author of the new book, Food Sense: What to Eat and Why. Thank you so much for talking with us today.

Dr. Christopher Gardner: It was a lot of fun, Mina. Thanks for having me.

Mina Kim: And thanks as well to our listeners for their questions and comments, and also to Ana De Almeida Amaral for producing today’s segment. Listeners, vote, then eat. You’ve been listening to Forum. I’m Mina Kim.

Announcer: Funds for the production of Forum are provided by the Jnerosity Family Fund and the members of KQED.