ZOE Science & Nutrition - Protein: are you getting enough?
Episode Date: April 13, 2023Proteins, carbs, and fats … most people understand what the last two are. Carbs are sugars, and fat is, well, fat. It's protein that’s so important to our diets, but so often misunderstood — b...y the general public, that is. Since the 1950s and 1960s, scientists have been measuring how protein affects our performance, how it supports and maintains the body’s structure, and how best to incorporate it into our diets. From big steaks to protein shakes, tofu to seitan, protein is more available now than ever before. With so many options, surely we’re getting enough protein? In today’s episode, Jonathan speaks with a leading nutritional researcher to find out. Christopher Gardner is a professor at Stanford University and a member of ZOE’s scientific advisory board. He’s pioneering the movement to redefine how we understand the quality of our protein intake. Download our FREE guide — Top 10 Tips to Live Healthier: https://zoe.com/freeguide 03:02 - Quickfire questions 04:19 - What is protein? 08:07 - Can our bodies make the proteins we need? 08:37 - The mechanism for our bodies creating amino acids. 09:33 - What is an essential amino acid? 10:45 - Crazy study Stanford scientists did to find the Estimated Average Requirement of protein. 15:24 - How much protein should we consume? 18:15 - How much protein do we already consume? 23:02 - Can our bodies store protein? 24:02 - What happens to excess protein in our bodies? 24:51 - Protein Scam Alert! 25:28 - Stanford Study: Does the type of protein we consume affect physical performance? 28:15 - Protein requirements for kids and pregnant women. 31:05 - What is Amino Acid Distribution? 33:03 - Are plants missing certain amino acids? 33:47 - How is AAD like the game of Scrabble? 38:30 - What is the healthiest source of protein? 38:41 - Dr. Gardner’s case for changing the way we define “protein quality” in the US 41:33 - Jonathan’s summary 43:59 - Goodbyes 44:42 - Outro Episode transcripts are available here. Follow Chris: https://twitter.com/GardnerPhD Studies mentioned in this episode. Maximizing the intersection of human health and the health of the environment with regard to the amount and type of protein produced and consumed in the United States Diet for a Small Planet by Frances Moore Lappé Perspective: The Public Health Case for Modernizing the Definition of Protein Quality Follow ZOE on Instagram: https://www.instagram.com/zoe/ Is there a nutrition topic you’d like us to cover? Get in touch, and we’ll do our best to cover it.
Transcript
Discussion (0)
Welcome to ZOE, Science and Nutrition, where world-leading scientists explain how their research can improve your health.
You've probably heard there are three main components of food. Carbs, fat and protein. Right?
What's your immediate reaction as I say those words?
If you're like most people, it's probably...
Carbs, those are bad, fat, even worse.
Protein? Well, I should probably eat more of that. We're always safe with protein.
As a result, food packaging everywhere is plastered with the slogan high protein.
What they're really trying to say is, hey there, I'm good for you.
Food manufacturers know this, certainly sell products.
For this reason, many of us are trying to eat
as much protein as possible.
We eat pounds of meat and fish,
guzzle powdered protein shakes,
and munch down high protein bars.
As a result, we consume far beyond the recommended allowance of protein each
day, confident we're making healthy choices. But are we? It turns out everything we've been told
about protein may be wrong. In today's episode, we'll hear what the latest science says from one
of the world's leading nutritional researchers, Professor Christopher Gardner. Christopher is the Director of Nutrition Studies at Stanford University,
a long-term member of Zoe's Scientific Advisory Board, and the lead author of a recent peer-reviewed
paper on recommended protein intake in Nutrition Review. Be prepared to be surprised.
Christopher, thank you for joining me today. And it's such a treat. We've known each other,
I think, for more than five years now. And for our listeners, Christopher is one of the top
nutritional scientists in the world, carrying out a whole series of big interventional studies
in humans, which are randomized controlled trials, which is very rare. He's been a longtime member
of the Zoe Scientific Advisory Board. And he's also been one of the authors of a major review of protein requirements
for nutrition review. So there's sort of no one better to talk about protein, which is one of the
topics where we've had the most questions from our listeners and members of anything that we've
touched on on this podcast. So I think it's gonna be a lot of fun. Thank you for being here with us.
Absolutely. This is a topic that is near and dear to my heart. Many myths to be busted.
Well, on the topic of myth busting, why don't we start with our usual quick fire round of
questions from our listeners. And just to remind you, Christopher, you know, the rules are quite
simple. You can say yes, you can say no, or if you have to,
you're allowed a one sentence answer, but no more than that. And we know that this is the hardest
thing for any professor to do, but are you willing to give it a go? Yes. All right. You've got the
hang of it already. Okay. Christopher, will I die if I don't get any protein in my food? Yes.
Do animals contain special proteins that you can't get from plants?
No.
Should we all be worrying about getting enough protein?
No.
Are protein shakes and protein bars healthy for most people?
Ah, compared to a tablespoon of sugar, healthier.
But I always say compared to what? Compared to food tablespoon of sugar, healthier. But I always say, compared to what?
Compared to food?
No.
I told you it was hard for a professor to answer these questions.
And the last question, can eating more protein help with weight loss?
No.
Okay.
I think a lot of people are already going to be surprised.
And I hope we're now going to unpack this in the rest of the podcast.
Maybe we could just start at the very beginning. So I think most of our listeners will feel they know what a fat is, right? They're thinking of like an oil they cook with or butter or,
you know, maybe the fat in a piece of meat. And I think almost everybody feels sort of confident
about a carb, right? It's like it's bread or potatoes or something like that. I think,
however, if a lot of people are like me, they're actually quite unclear really what protein is, except, you know, they're sure there's quite
a lot of it in a piece of meat because, you know, their mom always said, you know, eat your meat and
get your protein. So could you just sort of start at the beginning? What is protein and why do we
need it? Sure. So when it comes to fat and carb, that's really most of our fuel. When it comes to protein, it's more of our structure.
So all of our cells and our organs and our hair and our fingernails, all of that is structural
protein.
All the enzymes that are in our body that catalyze reactions and make metabolism move
forward, those are all proteins.
Many hormones are proteins. There's actually a huge list of
functional things that proteins do. And to take it to one next level, maybe this is helpful,
maybe this is not. All proteins are made of 20 amino acids in the human body. And I like to think
of them like Scrabble letters in the Scrabble board game or the letter somebody would put on
the marquee of a movie theater. And for perspective, there's a couple of them that are only three amino acids tied together,
which would be called a tripeptide, but that would be unusual.
The largest one I know of is something called maybe Tintin.
It's 35,000 amino acids strung together in a specific chain.
I was thinking about this like words and these amino acids like letters,
but you're saying these words can get really long and you need a lot of them. But fundamentally, you can make any word like any protein out critical is not only that the specific amino acids,
one after another, be perfect. Like if you were spell checking your writing in a document,
I would say, nope, that word doesn't work. So it has to be perfect. And then when the amino acids
are arranged in a certain configuration, these long strings of amino acids twirl and twist and
conform. They actually have to be side by side in just the right way. And
if you change that and unravel them, which happens in your stomach with a low pH, it happens with
heat, you inactivate the protein. And if it was going to have some functional purpose like an
enzyme or a hormone, it no longer works. And now it's kind of just like fuel. Now you can just
break apart the single amino acids and use them, but it can't function
like it was going to.
And that's why protein is so tricky.
So many things that it does, so many ways to activate and inactivate it.
And so Christopher, to make sure that I've got this, because that was a little scary
what you just described.
You're basically saying we eat food with proteins in it.
We break it down.
There are like 20 of the potential like
building blocks like letters, which is what you're calling these amino acids. And then
our body makes almost everything we're made of out of those like 20 letters in unimaginably complex
sort of combinations. I like the way you said that. And let me add one twist to this,
which is pretty interesting. There's very few rare exceptions to this. But when you say eat an animal protein or a plant protein, and it goes into your digestive tract, you can't absorb those
amino acids into your body until you break them down to their single amino acid levels. And then
you absorb them, travels through your body, reassembles them,
can't remember where it came from. Oh, did this come from a cow? Oh, did this come from a pig?
Oh, did this come from broccoli? No clue. It's like, oh, it's just this amino acid. I don't
even care. It came from a supplement. Can't even tell. It's just the building block.
Got it. So this is like I ate Shakespeare or I ate a comic book.
My body just breaks it down to letters. That just makes the protein sound even more important.
Follow on natural question about this is I think one of the things that we've learned on this
podcast is that our body has this amazing ability often to swap carbs into fat. So it doesn't really
matter what you eat always because your body will make what you need. Can't we just make these letters, these amino acids when we need them?
Yeah, I bet you a lot of people listening have heard of essential and non-essential amino acids.
I think it's a pretty non-essential question for all of your listeners, but I'm going to say it anyway.
While carbohydrates and fats are circulating in your body, the basic structure of those is
built on carbons of different lengths. And they have very complex metabolic pathways. And at
certain points in carbohydrate metabolism and fat metabolism, you can borrow one of these molecules,
put a nitrogen on it in the form of an amino group, which means a nitrogen with three hydrogens, an amino, amino reflects
this nitrogen portion, you can actually make 11 of the amino acids by borrowing something from fat
and carb and putting this ammonia amine group on it. And likewise, if you were breaking protein
down because you had enough for the day, which I hope we get to later because most people eat more than enough. If you take the amine, ammonia, nitrogen group off, you can put it right back
into the carbohydrate or the fat metabolizing chain. And that works for 11 amino acids. For
nine of them, there isn't a specific place you can borrow it from in your body. And so since you need
all 20 for just about every single
protein that you synthesize, you also have to get the nine essential ones. And essential simply
means you can't assemble the whole thing yourself. So to make sure I got that Christopher,
cause it got a bit scary in chemistry again, you're saying there are these 20, actually we
can make some of them ourselves, but actually like like i think you would say nine of them we can't make them so you've got to eat them you have to get those nine in order to
do you know essential things inside yourself is that do they get that all right so protein is
really important we need to get some let's talk about how much we therefore need which was the
number one question that we had as we were preparing for this show.
You're going to just have to stop me all over the place and get me to explain it in English because this will be harder. But basically, I'm going to take one big step back and say,
if you've eaten enough calories for the day, you've got enough protein. Just so stop obsessing
about protein. Protein's in everything. all 20 amino acids are in all plant foods,
big myth to bust here, and all animal foods. So if you're simply getting enough calories with a
reasonable variety in your diet, like if you only ate rice all day, you wouldn't get enough. If you
only ate cassava all day, you wouldn't get enough protein, but you also wouldn't get a lot. You also
wouldn't get enough of other nutrients. So let me tell you how people figured out how to get enough protein. This is disgusting. Are you ready? So I got...
We're ready.
I got my PhD doctorate at UC Berkeley in California. And they were one of the sites
that did some of the initial trials in the 50s, 60s to establish this. And the fifth floor of my building,
Morgan Hall in Berkeley, was called the penthouse.
And we got human subjects
that were conscientious objectors to the Vietnam War.
And they volunteered to live up there in blue zoot suits.
And the scientists would sequentially
lower their proteins successively down to zero and give them just carbs and fats.
And then they would raise the protein back up slowly in their diet. And every single day,
they would remove the blue zoo suit and they would vacuum it for all the hair and skin cells that
sloughed off during the day. They would collect all the poop, all the pee,
all the nose blowings, anything that left the human body was collected. Now we already talked
about this nitrogen thing in protein. And the initial studies were interestingly called
nitrogen balance studies. And instead of like analyzing amino acids in poop, analyzing amino acids in pee, analyzing amino acids in hair, you just burn it all up and analyze the nitrogen.
That's how much you can calculate how much protein left your body.
And then because they were nutrition scientists, they were calculating the amount of protein or nitrogen going into the body from food.
So they knew how much was going in and how much was going out.
They raised and lowered it for each individual until they were in balance. But Jonathan,
when they did this for a bunch of people, as you might imagine, what they found out is,
oh my God, this person in the room needed more than that person in the room. And when they
combined their data with a bunch of other folks who had done this same disgusting thing. They came up with,
in math, get ready for this, a normal distribution curve, which means, ah, a couple people needed
very little, a couple people needed a lot. There's a bell curve. So there was an average in the
middle. They did arrive at what would be the average, okay? And it's called the EAR. It's
very specific in this huge nutrition book, the estimated average Okay. And it's called the EAR. It's very specific in this huge nutrition
book, the estimated average requirement. Now here's an important question for you to think
about when you want to come up with protein recommendations for the country, what would
you suggest recommending? Would you recommend the estimated average requirement? Because if everyone
in the country got exactly the estimated average requirement, by definition,
how many people would be deficient? Half. Because it's the average amount. If you only get the
average amount, the half of you that are above average, not just intelligently, but from protein
requirement, would be deficient. And so this happens in protein and all the vitamins and
minerals, Jonathan. So when the U.S. comes up with recommended daily allowances for protein,
vitamins, and minerals, the standard approach is to take two standard deviations
above the average. And in mathematical terms, that means you've picked a number
that should be adequate for 97.5% of the population. And there might be a couple people in the tail
that need even higher than that, but it would be so few that you're pretty safe
recommending that amount. Now, not only is that amount adequate, but another math thing to keep
in mind here is if really everybody in the US or the UK, wherever, got exactly that 97.5% to standard deviations higher, how many would
be exceeding their requirement?
Oh, actually, like 97%.
Just to make sure I'm with you here, Christopher, because you're moving at some pace.
You're basically saying that when they came up with the recommended amount for protein,
they basically picked the amount that makes sure that almost nobody would have too little.
And as a result, you know, this recommended daily amount, which I've definitely heard from vitamins, right, and supplements.
You hear that very often. But I think anytime you look on the back of a food label, again, you know, I've definitely seen that for almost everything.
It's actually the amount that means almost everybody needs less than that. And so if you're getting the recommended daily amount,
you don't need to worry that you're not getting enough. Actually, in a sense, you might,
you're getting more than you need for almost everybody. So where does this take us?
At this point, we usually remind you about getting 10% off Zoe membership with the coupon code you can find in the show notes.
Though I would love for you to do that, I'm actually here to tell you about a common request we receive from people like you.
It goes something like this.
I've just discovered the show and now I listen each week, but I don't have time to go back and listen to all the previous episodes.
Could you share some of the key things I need't have time to go back and listen to all the previous episodes. Could you
share some of the key things I need to know how to improve my health? The team has gone back through
hours of recordings to find 10 of the most impactful tips led by science and put them into
a free guide that you can download right now. To get yours, simply go to zoe.com slash free guide.
Okay, and so what that takes us to is they came up with a number that said 0.8 grams of protein per kilogram of body weight should meet that.
And so I have a graph and a table that I can't show you because we have a podcast here.
But for a lot of people, that RDA level
would be maybe 40, maybe 50, maybe 60 grams of protein if you're heavier. So I have some U.S.
data that shows how much protein people eat in the U.S., and it's pretty much double the EAR
or double the RDA, just eating food, not even trying. And so to me, it's sort of this
American idea of good, let's see, that's what the RDA is, but I know I'm above average. So let me
make sure I get some extra here. It's like, no, you don't understand the concept. It was built in
to recognize that some people would need more. And as a nutritionist, when I teach students, I have to say, this is not an individual approach.
You should not look at the RDA to see if you are meeting your individual requirement.
This is a population health approach so that if everybody were to get that amount, almost
no one would be deficient.
And just as you were a bit surprised, every time I tell that story,
the audience I explain it to is a little surprised. And so Christopher, you know, I am
surprised because I've had this experience and I suspect there's quite a lot of people who've
had this experience. So like the first time I ever went to a gym, which is about 10 years ago,
and I had a trainer say, you know, this is what you need to do in order to get healthier,
which is what I was interested in and fitter.
One of the first things he said is,
oh, well, you need to eat more protein
and you need to eat at least a gram per kilogram of protein
if you're going to get, you know,
any benefits out of the work that you're going to do at the gym.
Now that number, because I think you just said
it was 0.8
grams per kilogram was your recommended amount, which is like the maximum that anyone in the
world basically needs. How did this happen? Why is there this controversy? Help me to understand
why there's this pressure about feeling people need to eat more protein.
Sure. Okay. So let's think about that
way. So there is there are some flaws of this nitrogen balance study that I suggested. And so
what happens in at least the US from all the databases I have is, and this is this is very
consistent in all research studies that I look at, most people get about 16, 17, 18% of their
calories from protein.
It's so consistent.
It's just amazing.
And then you look at how many calories you eat to maintain your weight.
And let's not go down this rabbit hole, but most people underestimate how many calories
they eat.
The data I have says women eat 2,500 calories a day and men eat 3,000.
And I know a lot of your listeners are going to say, not me.
I only eat 1,500 calories a day and men eat 3000. And I know a lot of your listeners are going to say not me, I only eat 1500 calories a day. We've done feeding studies where we gave people a certain
amount of calories, and it's really 2000 2500 or 3000. If you take 1617 18% of those numbers,
people tend to get about 1.5 grams of protein per kilogram body weight without trying. They're
pretty much getting double the RDA. So now here's what happens if you're in the gym getting that
double the RDA, right? Okay, so it's probably the 0.8 grams per kilogram met your need for enzymes,
hormones, fingernails, and hair. You went to the gym to lift weights and
gain muscle. So you probably want more than 0.8 grams per kilogram per day so you can put muscle
on. Okay, so let me tell you how many extra grams of protein you need. So Jonathan, how ambitious
would it be to put on 22 pounds or 10 kilos of pure muscle in one year. Would that be pretty good?
That I have to say sounds quite ambitious. I think if anybody saw me, they would say
totally ridiculous and impossible. But let's go with ambitious, shall we?
Okay, ambitious. So 10 kilos, actually 70% of your muscle is water. So if you were going to do that in a year,
all you'd actually have to accumulate is three kilos of extra amino acids or 3000 grams
of extra amino acids. Divide that into 365 days of the year. And just roughly, that means
you would need an extra 10 grams of protein a day to keep retain in addition to meeting your
maintenance needs to put this on now it's not quite a fair number because when you're in the
lifting and working out if you're working out really hard you're actually breaking down some
muscle using those amino acids and you have to replace them so So put another 10 grams on that. Say you needed an extra 20 grams
a day every day for a year to put this on. In the US, people are eating like 30 or 40 extra grams a
day over that 0.8 gram per kilogram every day, just eating food. And one more tidbit I have here
is when you're working out hard every day, don't you eat more? You do. You don't
eat just 2000 calories. I have a Stanford football player who was in one of the Rose Bowl games.
He was eating 5000 calories a day because they work him so hard. He was getting 260 grams of
protein every day without trying. He wasn't having shakes. He was just having food. So we
should go to like which foods have that protein. But if we could go here, I have one more place to
go is, well, wait, is that bad? What if you actually got more protein than you needed?
What would happen to all that extra? Will it kill you to have more protein?
What happens?
Okay. So, but I want to
go down a rabbit hole just for a minute for a fun exercise. So think on an average day, you probably
eat more carbohydrates than you need. And so once you've eaten some carbohydrate, the first thing
it says, Oh my God, does my brain need it right now? Nope. My brain's okay. Um, does my, do my
muscles need it? Now I'm doing a podcast with Jonathan. I'm just sitting here. I don't really
need my muscles. Okay. Well, I have a storage depot for my carbohydrate
and it's called glycogen.
And there's some in my muscles
and there's some in my liver.
So I will try to fill up my storage capacity
of glycogen, stored carbohydrate,
so that I can have some later in the day.
And do you know how long it would take you
to deplete all the storage carbohydrate in your body. Any idea? Are you a
runner, Jonathan? Actually, I don't know this if you're a runner. No, I'm very good at sitting in
my chair doing podcasts. But tell me, how long does it last for? So I bet you've heard that
marathon runners at 20 miles bonk if they don't have enough carbohydrate. That basically means
you've used up all the glycogen
that you stored in your body. It's only about a kilo. Okay, let's switch for a minute to fat. So
let's say you ate more fat calories for the day and you used it for various things and mostly you
burned it for energy. Where would you store that and how much could you store? And I'll save you
the trouble here. You can store an infinite capacity of fat. Oh my gosh,
you can store hundreds and hundreds and hundreds of pounds of fat in your butt, in your thighs, in your jowls, in the pads in your fingers, endless capacity to store fat. It would take you
an incredibly long time to use up all the storage of fat that you have in your body. So unlimited
capacity to store fat, a very limited capacity to store carbohydrate.
Where could the extra protein go? So your trainer told you to do this. You ate all that extra
protein. You made your enzymes, you made your hormones, you lifted your weights, and it was a
little more than you needed, or maybe a lot more. And you're going to bed tonight. So where do you
think you put it in your body? Is it in your spleen, in your liver,
in your big toe, in your elbow? Where's your protein storage? Where is my protein storage?
None. Every bit of it at the end of the day has the nitrogen taken off and it gets turned into
carbs and fat. You can't store protein in your body. So the muscle heads who are having a lot of meat
and regular meals and a protein shake and a protein bar are turning all that into carbs and
fats at the end of the day. And I'm just going to turn it into basically fat that I lay down on my
body. Is that what you're telling me? And yet the nitrogen will be taken off, your liver will turn it into ammonia, and your kidney will
excrete it and get it out of your body. And so you actually could suck out some calcium as it goes.
And so some people say don't eat too much protein, it'll suck the calcium out of your bones. Let's
not go down that rabbit hole. It probably doesn't happen. Most people with a healthy kidney can
eliminate this just fine. You might know that if someone has an impaired kidney,
one of the first things they do from a dietary perspective
is they ask them to limit their protein
because they don't want their impaired kidney
to face the challenge of clearing more of this excess ammonia
from the excess protein that most people get in a day.
But to be honest, most people's bodies are set up to handle this,
turn it into carbon fat and get rid of the ammonia.
So for most people, eating that protein isn't necessarily bad for you unless you consider what came with it.
So if this is a lot.
I was just going to say, isn't this like a I feel like this is a huge scam. these products that are on sale that say you know no carbs 10 grams of protein or you know
like no sugar 10 grams of protein and then you're telling me i eat it i haven't i'm already eating
more protein than i need so my body is just going to turn that into carbs and fat and since i we
know i already am eating as much food as i need, like if I'm having that on top,
I'm just basically going to turn it into body fat. Is that, have I got that right?
In the end, it all comes down to calories. So Jonathan, we just finished a fun little study
with a master's student. We hope to expand on it. We got 22 Stanford graduate student
recreational athletes who have been for five or six years working out every day. They're not
competitors. They just work out all the time.
They want to stay fit.
12 of them are runners.
12 of them are weightlifters.
Six in each group are men.
Six in each group are women.
For four weeks each, we had to meet an omnivorous diet, a vegan diet, or these plant-based
alternative meats.
And the outcomes, instead of my usual cardiovascular thing with lipids or blood pressure or whatever, were push-ups, pull-ups, bench press, lat pull-downs, leg press. And for the runners,
a timed 12-minute run to see how far you could run. And it was four weeks each. It's a preliminary
study, but they were all kind of shocked. They ate much less protein on the vegan phase,
and their performance was not different than in the
omnivorous phase. They didn't lose any performance. And if you look, they were getting all the protein,
as much protein as you needed by various athletic association type things. They weren't taking any
supplements, no shakes, no bars, just eating a vegan diet. And another paper came out just this last month that someone
sent me saying the same thing. And Stu Phillips, who's a fantastic exercise guy from McMaster
University, he and I did a podcast together and said, yes, you know, that 0.8 grams per kilogram
number isn't right. It should be higher than that. It may need to be as high as 1.6. And I said,
but isn't that what people eat anyway? He said, well, yeah, that's actually what they get anyway.
So if you weren't getting that much, it's possible you could be impaired and you would benefit from
this. But if you were tracking your calories right, and if you're eating a reasonable variety
of diet, you wouldn't have to do what the trainer said to you. You wouldn't have to take any extra effort to get that amount of protein.
And Christopher, I think that's, it's very clear. It's sort of amazing. I do want, however, to spend
a little bit of time talking through sort of the different ages of people, because we had so many
questions on social from our listeners about concerns about
protein requirements at different ages so i would love to start actually maybe with children um and
i just have this sort of personal experience right now so i have a 15 year old and his friends have
started drinking these new energy drinks that say they have added protein which is a new thing for
me that wasn't what i you know i wasn't even aware that that was a thing.
They've gone past caffeine.
Is there any evidence that at this point, when you're growing really fast, that actually
kids might not be getting enough protein and we need to really worry about that?
Yeah.
So for kids, if you go back to all those old RDA calculations, kids need not 0.8 grams, but at
different ages, they need 0.9, 1.0, 1.1, because they're growing. Similarly, for a pregnant woman
that's growing a fetus inside of her, she's not just maintaining, she's growing. And so those
needs are higher than 0.8 grams per kilogram per day. The question is, can you get that just eating food?
Or do you need to get these extra sources? And as I'm suggesting, the food supply,
as long as you get a reasonable variety, and we should get into plant food versus animal food,
but you would have to work really hard not to get that much protein. Jonathan and I attended
the job talk of a nephrologist at Stanford who isn't a nutrition person said,
God, you know, I'm trying to work with these people with impaired kidneys and I've been
trying to get them on this really severely restricted protein diet of 0.7 grams per
kilogram body weight. And I can't get them there. And I laughed and I said, 0.7 grams per kilogram.
It's severely restricted protein. That's practically the RDA. He said, yeah, I can't get them that low.
I get them to try to eat this and that, and then I can't get them that low. It's hard not to get
it. And so does that mean, you know, as a parent, you know, you don't really need to worry about it?
Well, isn't your refrigerator empty? So I have four boys.
Yes, he does eat a lot of food. There's no doubt.
They bring their friends and it's like, I skipped dinner.
Really?
Aren't you eating?
Oh no, I had like two pizzas a half an hour ago, but I'm skipping dinner.
Oh my God.
And then I go out at midnight and he's having a sandwich.
It's like bottomless pit.
Now, if you go to the other end of the spectrum, there's possibly some issues with elderly
because digestive tract, denture, dentature.
So, you know,
they're not chewing enough food. They've sort of lost their appetite. We have this issue of sarcopenia where they're losing muscle mass. There've been some studies. It's not really
just the hormones. It's loneliness. It's depression. It's not eating. It could be
that you have to make special effort to make sure in the small number of calories that they're
getting that they are protein rich because they're just not eating very much. So Christopher, you'd be very patient
about not talking about where the protein comes from. So let's do that. And we had lots of people
asking us basically, you know, sort of versions of the same question. Is animal protein better than plant protein? And
how are they different? And why is it that one might be better than the other?
Hi, I love that you're listening to this. It means a lot to me and the whole team who put
such a lot of hours into this podcast each week. We release this show for free without ads
to help millions of people improve their health
with cutting-edge science.
In return, all I ask is that you help us on this mission.
If you know someone who'd benefit from listening to this episode,
please send them a link to this show.
And if you haven't already,
hit follow wherever you're listening right now.
Thank you, and on with the show.
Yeah, so you're killing right now. Thank you you look at the estimated average requirement of protein for a lot of people, it could be close to 40 grams of protein, which is
pretty low. And I like to use that number just for fun to make this one point. There are 20 amino
acids. If you need 40 grams of protein, simplistically, that sounds like it would be good to have two grams of each one. Two times 20 is 40. Not even
close. So you need tons of glutamate, glutamine, aspartate, asparagine. You need hardly any
tryptophan, methionine, cysteine. And the best way I've found to describe this is the game of
Scrabble. So Scrabble, which my wife beats me at regularly, is 100 tiles in a bag.
And I don't know if you know this, from one country to the other, the distribution of
letters is a little bit different depending on how often those letters are used in the
language of that country.
I've learned about Scrabble and protein now, Christopher, so it's great.
So think, 26 letters in the alphabet.
There's 100 tiles.
Aren't there four of each letter
in the Scrabble bag to make your words? No, there's only one Z, there's one X, one J, and there are a
whole lot of E's and A's and N's and R's. Amino acids are just like that. So what I did is I sort
of made a graph and I showed, ah, here's the distribution of 40 grams of protein
in eggs, in chicken, in pork, in fish, in beef. And the distribution is stunningly similar. And
I say, wow, that's pretty interesting. All the animals have a lot of the same ones and a few
of the same ones. And then I say, okay, so you've all heard plants are missing amino acids. Which
ones do you think they're missing? Are different plants missing different amino acids? And I put
up some fake data and I say, which one do you think is rice and beans and broccoli? And I don't
let them think for long. And then I put up the actual amino acid distribution and their jaws
drop. All of the plants have all 20 amino acids. The distribution of the amino acids is almost
identical in the plants as the animal. And they say, what have been people telling me?
Professor Gardner, are you lying? Did you like make this up? Because this is not the reality
that I've been told. And it's a very simple kind of trivial thing, Jonathan. So rice and other
grains in general tend to be low in the proportion of lysine that they have relative to the optimal
proportion. And likewise, beans tend to be low in methionine and cysteine in proportion to what
they need. And so I like this Scrabble analogy. So picture that you've
had this Scrabble game for a really long time, and you lost the L for lysine and the M for
methionine. Are you missing all the L's and all the M's? No, actually, you only lost a couple of
the letters. So if you were using your board and trying to make words, you would run out of
words you could make with L and M sooner. What if you had a neighbor who also hadn't played Scrabble
in a long time and they'd said, oh, I'm so sorry you're missing those letters. You can have my
Scrabble bag of letters. Oh, I'm also missing an L and an M. I'm sorry. You could still fill up the L and the M that you were missing because your
neighbor has extra L's and M's. And I think Americans eat at least 80 grams of protein a day,
not 40 that they need. And so I'm thinking, what if you had two bags of Scrabble letters?
Oh, that's like what Americans eat in protein every day. Two bags of Scrabble letters.
And if they're eating plant proteins,
they are lower in lysine and methionine
than would be optimal.
But that's only a concern
if they only get 40 grams of protein
and they need every amino acid to count,
but they get 80 grams of protein,
even the vegetarians and the vegans.
And Christopher, just one clarification.
I think that it sounds like in general saying, don't worry about this. Are you saying, 80 grams of protein, even the vegetarians and the vegans. And Christopher, just one clarification.
I think that it sounds like in general saying, don't worry about this.
Are you saying, because you're mentioning two particular amino acids that I can't pronounce.
Are you saying that in all plants, the relative amount of that is lower than it is in animals?
Yes.
So even if you're having a variety of plants, so it's not just that like one plant is low in the L and the other one is low in the M. Actually on average, like all plants are lower
in that relative to animals. And therefore, if you were eating a plant only diet, then if you
were going to eat the 40 grams of protein, you're going to have potentially a low level of those two particular
amino acids. I just want to make sure that I'm... Yeah, if you needed 40, it's not really to need
40. You need 40 in the right distribution. If you only ate rice all day, that's how you got
your 40 grams of protein, you wouldn't have enough. Even if you ate 40 total grams of protein,
you run out of lysine too soon. If you only ate beans, you'd run out of
methionine before you got enough. So you could supplement with just those individual amino acids,
or you could eat 80 grams of protein a day, and you would end up getting the things that you're
missing. Now, here's what happens is you really only needed 40 and you ate 80. What do you do
with the extra 40? You break 40 down and turn it into carbohydrate and fat. But that's typically
what's happening is that people eat more than the total amount they need. And so given that plants
don't have the ideal distribution of amino acids, they're almost always covered. And you just break
down the other ones. So there is, Jonathan, an old concept that was written up in Francis Moore
Lappe's Diet for a Small Planet
about complementing your proteins because the grains that are a little low in lysine are a
little high in methionine. And beans are a little low in methionine, but they're a little high in
lysine. And I say, ah, this is sort of a no-brainer. That's why some populations ate grains and beans
together, because they complemented the deficiencies with the excesses. It's still never quite as good as meat.
It's still not the optimal distribution, but it's closer to optimal.
So you can either try to complement them or you cannot worry about it
because you probably ate 80 or 90 grams and you didn't really have to think about it.
I just want to make sure it's clear because there were a lot of questions around this.
If you're eating a plant-only diet, if you're eating a, and you're not just eating one plant,
as you're describing, but you're eating a varied plant diet, do you need to worry about
protein, or are there particular cases?
For example, again, does that make you more concerned with the older people or anyone
who's not eating a lot of food? Just want to understand in that,
I understand it's a bit of a corner, but I think I want to make sure we have a clear answer for
our listeners. As long as you have access to a reasonable variety of food, you don't
need to be worried. You don't need to be worried about your vegan kids. Yes, you can absolutely
meet all your needs on a completely plant-based diet. Stop obsessing about protein.
Thank you. Brilliant answer. So let's say that someone's listening to all of this. You haven't
managed to completely convince them that they shouldn't have protein because it's hard to shake
that. So they're saying, okay, but like I'm worried, or maybe I do fit into one of those
categories that we're talking about where they are potentially concerned about it.
What's the healthiest and tastiest source of protein that you would recommend?
Beans, hummus, all the three bean soup, a three bean salad.
So David Katz and some other colleagues and I wrote a paper called Modernizing the Definition
of Protein Quality. And in it, we said, okay, so there's this one issue of the distribution of amino acids,
perfect in animal foods, less than perfect in plant foods. There's actually an issue of digestion
and bioavailability, and it is a little higher for meat protein than plant protein. But when
people are eating meats, they're getting a lot of
saturated fat. And they're sometimes getting hormones and antibiotics were used to grow that
meat. And there's no fiber in there. If you were eating beans, and tofu and tempeh, and plant foods,
you'd be getting much less saturated fat, you'd be getting phytochemicals, antioxidants, you'd be
getting lots of fiber for your microbiome. You guys at Zoe might have heard about the microbiome. That's a pretty cool thing. And so this idea of should
the protein quality definition in the US is based on amino acid distribution and digestion and
availability. And we propose that it should also include the nutrients that come with those foods
rich in protein, which in your bar was sugar,
in that meat was saturated fat and no fiber versus those beans and grains that had antioxidants
and other things like that. And if we're going to be eco warriors these days and not destroy the
planet we live on, the legumes and grains are much easier on planetary boundaries of land use,
water use, greenhouse gases, eutrophication, and biodiversity.
And I think, you know, just to add on top, we discussed this just a few weeks ago. They're
also incredibly cheap. You can buy them in cans. They last, which means you capture like all of
those nutrients sort of at the point of picking, and then they sit there for months. So I think
beans have had the worst possible marketing, probably because nobody can lock down the copyright in the
same way as for that protein-enriched drink that my son was discussing with me a couple of weeks
ago. Uh-huh. But I mean, oh God, I make a wheat berry salad with some nuts and whole grains in
there. And I eat hummus all the time. There's plenty of ways to incorporate really fun
Mediterranean, Middle Eastern, Latin American, South Asian dishes that really evolved around
grains and beans. So there's just a global fusion of flavors out there for you. You do not have to
look hard. And your message is even if you're trying to, you know, be fast around the track or pumping your iron or all the rest of it, you don't in fact need to be sort of eating a steak a day.
Eat food.
Yeah.
Wonderful.
Christopher, this has been an amazing tour.
I would love to try and do a little summary and then please keep me honest if I got
anything wrong. Is that all right? Ready.
Absolutely. Well, I think first you explained what is protein. And what I took away from this
is like fat and carbs are like the fuel that power us through the day, but protein actually
creates the structure. So like everything we're made of basically comes from these proteins and that they come from these 20 amino acids, which I'd never understood what that was before.
But now I've got in mind, they're sort of like the letters in the alphabet. And then I'm like all these words that get created out of these letters.
In terms of how much protein we need, the answer is far less than any of us realized or have been led to believe.
Your colleagues at Stanford, you know, a long time ago did these crazy studies of people sort of wrapped up in suits to understand exactly how much they needed.
And it turns out there's a lot of variation between people.
And I'd love to figure out how we might be able to measure that at home somehow in the future.
But at the moment, we can't.
Christopher is shaking his head. There's always some new technology, I feel, that maybe that will
make it happen. But at the moment, you can't measure that for yourself. But what they did is
they figured out sort of what's the maximum that almost anybody needs. And that was actually only
0.8 grams per kilogram. And on average, in the US, people are eating double that already, which means that they're
eating far, far more in fat than they need. So they don't need to worry about it. And then we
talked about, well, what about if you're not eating lots and lots of animal protein? Is that a problem?
And the answer was really not, that actually there are all the amino acids in plants.
There are a couple of these amino acids which have lower amounts relatively.
But since we're all eating so much of it, it's not really a problem.
And I think the final point was almost anything that says like extra high protein on it or, you know, a bar or a shake or any of these things are just really bad for you.
Don't eat them.
And I think, Christopher, your message is eat beans instead.
Yep.
Perfect.
I don't know why it took me an hour to say all that when you just said it in three minutes,
which is pretty good.
Well, one critical mistake.
So those old studies in the blue zoot suits were Berkeley, my alma mater, not Stanford,
my current place.
And, you know, there's a lot of competition between the two.
I don't exacerbate that.
I can see that I'll be in a lot of trouble.
You'll be in a lot of trouble there.
So I apologize.
Christopher, thank you so much.
I think it was fascinating.
And I think there's a few of these points that I'm sure we could go into in more detail in a future podcast but i certainly think you will have hopefully made a lot of people feel more relaxed
which is great and also probably look very differently at these foods that say no sugar
and 10 grabs of protein because they now realize if they eat that just before they go to bed they
might as well just have had a chocolate bar it would have been more fun and he would have had
the same result which i had not previously realized um so uh probably don't do that at home okay great it
was very fun having this discussion and yeah i hope some people learn some things thanks jonathan
it's such a pleasure see you very soon christopher thank you christopher for joining me on zoe science
and nutrition today if based on today's conversation you'd like to understand how to support your body with the best food for you, including plenty of high quality sources of protein, then you may want to try Zoe's personalized nutrition program.
Your Zoe membership comes with meal and recipe recommendations, access to our nutrition coaches and scientifically backed nutrition advice on how to eat for your best health so you can feel more energetic and reduce the risk of chronic health conditions.
Your personalized nutrition program is based on our scientific research and the results of your personal at-home test.
If you're interested in learning more about Zoe, you can head to joinzoe.com slash podcast and get 10% off your purchase.
If you enjoyed today's episode, please be sure to subscribe and leave us a review as we
love reading your feedback. If this episode left you with any questions, please send them in on
Instagram or Facebook and we'll try to answer them in a future episode. As always, I'm your host
Jonathan Wolfe. Zoe's Science and Nutrition is produced by Fascinate Productions with support
from Sharon Fedder, Yela Huynes-Martin and Alex Jones here at Zoe. See you next time.