​

Neha Pathak, MD, FACP, DipABLM: Welcome to the WebMD Health Discovered podcast. I'm Dr Neha Pathak, WebMD's chief physician editor for health and lifestyle medicine. How many times have you walked down an aisle in your grocery store and seen packaged foods labeled as "extra protein" or "your daily dose of protein" and wondered, "Is this cereal or breakfast bar or a package of popcorn really a good source of protein? Do I actually need this much protein? How much protein should I actually be eating every day?"

Well, today we're gonna explore the current protein obsession. We'll also dig into how high-protein diets, recipes, and ultra-processed foods are dominating the conversation about health and wellness but leaving out crucial information.

Today, we'll answer some of your most important questions, including: How much protein does an average adult really need for health and muscle maintenance? And when, if ever, do high-protein intakes actually add real benefit? Is there a difference between getting protein from an animal source versus a plant source, and how should we think about that with regard to our long-term health? And how does protein fit into the big picture of overall health and well-being?

Finally, we're gonna dig into healthy ways to reach our daily protein goals without strict tracking or relying on ultra-processed foods.

First, let me introduce my guest, Dr Marily Oppezzo. Dr Oppezzo is a learning and behavioral scientist, an instructor of medicine with the Stanford Prevention Research Center, and a Wu Tsai Human Performance clinician scientist. She has a PhD in educational psychology and training in behavior change.

She's the head of the nutrition pillar at Stanford Lifestyle Medicine. Dr Oppezzo's research mission is to identify small but mighty ways to help people effectively integrate healthy behaviors into their lives to improve their health and well-being.

Welcome to the WebMD Health Discovered podcast.

Marily Oppezzo, PhD, MS, RDN: Thank you for having me.

Pathak: I am really excited for our conversation today because, as a lifestyle medicine provider, I get questions all the time about optimal dietary patterns and, in particular, protein, and what is the optimal way to take it? How much should we have? All of those questions. So I am so happy that we have your expertise to help us answer all questions protein-related.

Pathak: But before we get there, I'd love to ask about your own health discovery in the work that you do. What questions or issues arose in your life or in your research that inspire what you do?

Oppezzo: I'd say my inspiration definitely started with my dad. He taught health and coached all the sports at my high school. He actually is cooler than I am, so at my reunions, everyone always asks about my dad. He had this belief that everybody was an athlete inside, no matter who you were, and we all had capabilities we hadn't tapped into yet.

So he was a Hall of Fame athlete himself, like right next to Barry Bonds at his high school on the wall, and I was the exact opposite. Nobody knew that I was his daughter. I was literally the worst at every sport I tried. But he always made me feel like an athlete, and he showed me if I tried hard and practiced, I could always get better and that pretty much anyone could if I could.

So fast-forward to when I'm 30. I'm getting my doctorate at Stanford, and I found out a week before finals one quarter that I had severe congenital heart defects, like a whole bunch of them: two holes between the chambers, pulmonary veins pumping the wrong way, all my valves leaked, and this had been going on my whole life.

I just always thought that stairs were hard for everyone, so I was never really a cardio fan. And I had, like, urgent open-heart surgery, I guess, a couple weeks later, and I literally started at zero. I could walk for, like, six seconds before pain shot up my leg 'cause I had the heart-lung bypass machine in it for so long.

And this was after running six miles the morning before my open-heart surgery. So I knew it was gonna be a long journey. My dad was there for all of it, and that recovery taught me everything about my current research, I think, because I learned that little things matter. I had an Excel spreadsheet of six seconds, seven seconds, like, the amount of time I could walk without pain, and even though I tracked it every day, I knew it went up sometimes and down sometimes, and I knew that I had to look at the week level because looking at the day-to-day fluctuations was too much.

And I realized that most people aren't gonna get this kind of dramatic, overnight transformation through lifestyle changes and that this is really hard. So that's my real challenge, is helping people stay motivated when progress is super gradual and sometimes backwards, when changes happen over weeks and months and not in dramatic moments.

And then how do we sustain it when the rewards are really subtle and they build up over time? So that's kind of the theme of what I do now with both nutrition and exercise.

Pathak: Wow. Your story is unbelievable, amazing, so inspiring. Thank you so much for sharing that with us.

Oppezzo: I think what also really hit me as you were talking—I mean, so much of it is just so inspiring, your father's story, your own—but it's just how much so many of these small changes are intertwined. So it's, yes, the physical activity and the slow monitoring and recognizing that this is gonna be a slow process, but it's also what you're eating while you're in recovery, and I think this is what trips a lot of people up because we want simple answers or, "What's that one thing that I should do?"

Pathak: And I think a lot of people right now are thinking, "Well, okay, can my one thing just be really focusing and tracking my protein intake?" So I'd love for us to kind of dig into that piece for sure, but also reflect on and recognize at the very beginning that this is one piece of a much larger puzzle where a lot of habits have to align for optimal health and to see these big improvements.

Pathak: What exactly is protein, and why do our bodies need it?

Oppezzo: Okay. So it's basically the structural material of our bodies. We've probably heard it called the building blocks. It's made up of amino acids, and people think of protein—it's basically something we have to eat every day. It's a source of nitrogen. We can't get nitrogen from carbs or fat.

And people think protein is just muscle, right? 'Cause muscle is protein, but that's a luxury item. Protein makes up all of the things in our body, like enzymes, our hormones, our organs, our skin, our heart, our brain, our liver. It's 40% of our bone mass. It's not just a stick of chalk. So unlike carbs and fat, which basically fuel our bodies and what we do all day, protein has a ton of other jobs.

So, like carbs, one of carbohydrates' roles is actually protein sparing, which means it does all the things like, "Hey, let me give the body energy so you can go do all that other stuff." And we need it every day because, like carbs, we store as glycogen in our muscles, and fats we store as, well, fats.

And then we don't have a storage form of muscle, and we're constantly breaking down and rebuilding things in our body. So Luc Van Loon is a researcher who famously talks about how we get a new arm every 80 days because our muscle is always breaking down, even if we're not, like, actively strength training.

It's breaking down and rebuilding. And our GI tract is more like a couple of days to a week, and we have a completely new GI tract, which is great. So the protein's always doing background stuff, and it's not just our muscle.

Pathak: That is wild. I did not know that. What an image. So thank you for that. That is really interesting.

So let's talk a little bit more about protein in the sense that it's trending across social media. I mentioned so many of my patients are talking about it, a lot of my friends are talking about it, and they are all sort of thinking about and trying to figure out what is that optimal number that I need to get to for good health.

From a medical perspective, is that a number that people should be chasing for good health?

Oppezzo: Yeah. Well, what's trending on social media is sort of—I kind of grew up in the weight room because I couldn't do cardio. I didn't know why. But the bodybuilder lore was like a gram per pound of body weight, right? Or 2.2 grams per kilogram of body weight. This is for sure not necessary for good health.

So, if you really wanna track, you know, somebody who does and researches protein—his whole lab is called the Protein Lab—for a living, check out Stuart Phillips up at McMaster University. He's spent his whole academic life looking at this, and research from his lab that's corroborated by others shows that the benefits pretty much taper off after about 1.6 grams per kilogram of body weight, which, for us with the metric system that we have, is 0.7 grams per pound of body weight.

You wanna take your weight and then you wanna multiply it by 0.7 grams per pound to find out how many grams of protein you need.

So what's necessary for good health is maintaining muscle, and protein has some part of that.

But I wanna say—and I'll say it later too, probably—strength training has the most to do with that.

Pathak: So why do you think so many people believe that high-protein diets equal healthy eating?

Oppezzo: Because we already had a trend with carbs and fats. And so now it's protein's turn. Some sources of protein are really healthy too, like lentils, Greek yogurt, eggs. They all have a lot more to provide the body than just, like, a croissant or Pez candy, right? So, a lot of whole-food sources of protein are great.

And people are finally also realizing that muscle's important. I think strength training finally showed up at the Academy Awards because cardio's always been king and queen. But we associate protein with muscle because it is protein, but also so is our spleen, so is our liver, so no one gives protein credit for the other organs.

But since muscle's so popular now, I think protein is getting a play. And also it's really countable. It seems to be cooler than other healthy things like fiber to count. Nobody's walking around tracking their fiber or fiber-maxing. So yeah, I don't know. I'm not quite sure how it's gotten its day in the sun, but those are three possible ideas.

Pathak: So where does social media get it right? Help us understand why we should include some understanding around having protein in our diet as part of the healthy diet conversation.

Oppezzo: Yeah. So in the beginning, they were right that protein matters, and a lot of people, especially as we age, probably aren't getting enough. A lot of the non-20-somethings, so like my age, grew up probably eating a lot less, like, you know, a bagel or croissant for breakfast, huge loaves of bread with a tiny piece of meat in the middle for a sandwich.

And so we are learning that all of the less nutrient-dense carbs should maybe decrease and that protein should increase. And that doesn't mean we get rid of carbohydrates; it's just that the proportion of just sort of white flour to the substance of the sandwich, maybe those proportions should change.

The focus is helpful to shift towards something that we've been under-prioritizing. But the problem, I think, as with everything in America, is that we seem to be very extreme. Once we decide something's important, it's only about that, and we're getting the message wrong. So in addition to being extra, we're also being way too simple about it.

More isn't necessarily better, but also just shoving protein at muscles isn't gonna make them bigger or stronger. Only physically challenging them is. So Stuart Phillips, once again, I'm gonna quote him and give him credit for this now-famous cake analogy of his, which is that exercise bakes the cake, and protein is this super tiny, thin layer on top of the cake in terms of muscle.

And protein-maxing could probably crowd out other things. So like you talked about, like fiber, fruits, and vegetables. Fiber is the much less popular cousin, but it's super major. And I think it's just easier nowadays to be super extreme because you can literally put protein into everything.

Pathak: So help us understand then how much protein an average adult really needs.

Oppezzo: Right. So the RDA, the Recommended Dietary Allowance, is 0.8 grams per kilogram, which is like half of what I told you the upper level is as far as benefits maxing out. And that's about 0.35 grams per pound. This is too low. Experts agree that this is too low. It was basically calculated a long time ago when nitrogen balance methodology was in play.

It was the gold standard at the time, but we have better methods now. And that was probably the amount to survive, but not thrive. So for most healthy adults, we see the optimal level being around 1.2 to 1.6 grams per kilogram of body weight, and that's about 0.5 to 0.7 grams per pound. Again, take your body weight and multiply by 0.5 to 0.7 to get your range.

1.2 grams, or the 0.5 per pound, is if you're just existing, not actively losing weight, you're not sick or catabolic, meaning you have a disease that's kind of breaking down a lot in your body, and you're not particularly active. 1.2, I'd say, is the "chill out, you're gonna be fine." 1.6 grams per kilogram, or 0.7 grams per pound, is the point beyond which you don't really see much added benefit.

There's a couple populations that need to be more diligent and stay around the 1.6 end, 'cause that's a big range, right? 1.2 to 1.6 grams per kilogram, or 0.5 to 0.7, that's a difference of about 25 to 40 grams. I think as we age, we need to pay more attention because we eat less and we move less.

So both of these things affect the use of protein for muscle building. If you're actively losing weight, you may benefit from the higher end or even a bit above because you want to preserve muscle when you're in a caloric deficit. So, we don't have a storage form of protein like I said earlier. If you eat too much protein, you just use it as energy or you store it as fat.

And I think that that's not well known, but too much protein will be stored as fat. But your muscles are an easy-access place of protein, so if your body's not getting enough protein that day or you're burning the protein you are eating for energy, your body will look around and be like, "Oh, wow, the quad muscle looks really great. Let's get some amino acids from there before I break down your liver."

So, muscle, again, is a luxury, so you don't wanna take the protein that you didn't eat that day from your heart. You're gonna take it from your muscle. So it's not actually a storage form, but it serves as one if you're in a super caloric deficit and you're not eating enough.

So, just protein is helpful for muscles, but you need the bricks to build the brick wall, but you also need the bricklayers to get the message to build it. So otherwise, the bricks just get used for energy or fat. So you can't just eat protein popcorn and gain muscle.

You have to send the message that you need to build the muscle.

Pathak: So what happens if you get too much protein? Are there health risks for consistently eating too much every day?

Oppezzo: So 60 years ago, I think Dr Brenner came up with a hypothesis that it could be bad for your kidneys, right? And I did my dietetic internship at the VA hospital, and the most challenging beat was the dialysis unit for dietitians because you have to be so judicious about what you eat in between dialysis sessions.

So when your kidneys aren't functioning anymore, their job is to filter your blood, and they get rid of, like, the nitrogen from the protein that you ate, but also potassium, phosphorus, sodium, all of the things that go out in your urine. However, if you go every three days to filter your blood through a dialysis machine, in those three days, you don't wanna build up all of that stuff because that's bad, 'cause your body can't get rid of it.

So yes, in that case, we had to have people on a lower-protein diet because it kind of would accelerate the already compromised function of their kidneys. But they're not there because eating more protein caused kidney damage. They already have kidney damage, and then we're maximizing the life of the kidney by minimizing the kind of stuff that it has to deal with.

So there's no evidence in those 60 years since that hypothesis that eating more protein will wear out your kidneys if your kidneys are healthy. So that being said, can you eat too much protein? Yes, if you become so obsessed with it that you stop eating plants and fiber and a variety of foods that are good for your microbiome, that's a problem.

There's no fiber in a chicken breast and no phytochemicals in a protein shake. And in the carnivore world, if all of your protein that you're eating is red meat and animal proteins, that comes with saturated fat. So it's kind of what are you having with it and what aren't you having, and that's what I start to worry about because bacon and ribeyes for your meals are not a good longevity plan.

Pathak: So let's dig into that piece then. What are the differences between animal-based and plant-based proteins in terms of, you've said, some of the guests that come along with that food? So tell us a little bit about the differences and the health benefits and if there's anything different in the way that our body uses protein if it comes from an animal source versus a plant source.

Oppezzo: Yeah, our body is so cool because it doesn't care where you came from. I like to think of the inside of the body as a club that your nutrients want to get into. And everyone who wants to get into the party goes through your GI tract, which is actually considered outside your body. And the doors to get into this club are very small and specific, and you can't get in with your whole posse at once, and the doormen don't care about your origin story.

So protein is similar. No matter if it came from steak or tofu, it's gonna be digested and broken down into individual small Lego pieces, those little building blocks I told you about. Single, double, triple amino acids. Doesn't matter where it came from, those amino acids are just gonna be these little single, double, triple Legos.

And then once it's inside your cells, it's like the waiting area to get into your body. Everybody just becomes a single Lego, a single amino acid. So you'll still be leucine if you were leucine, which is an amino acid, or histidine. They're still themselves, but your body doesn't know where it came from.

And your muscles can't tell the difference between a leucine that has come from a protein powder or milk. And as long as you're getting enough of all of the nine—so there's like 20 amino acids, and nine of them are the ones that we cannot make. We actually have to get them from food.

We can cobble together the other 11, but we can't make these nine. And so you need enough of these nine essential amino acids to do all of the things that we talked about. And that's where the difference between animal and plant proteins kind of comes into play, is that animal proteins are complete in that they have enough of all essential amino acids in good amounts, so you could just eat them.

And most plant proteins are lower in one or more of those amino acids. It doesn't mean that they don't have them at all, though. You just can't eat only one source. So rice has protein. Everything has protein. But if all you eat is rice all day long, you'll miss out on lysine. And it's wild because cultures around the world throughout history have figured this out.

There's beans and rice in Latin America, lentils and rice in India, hummus and pita in the Middle East. Everybody has figured out how to kind of pair these foods together. You don't have to pair them at the same meal. You basically can eat them throughout the 24 hours, as long as you just have rice in the morning maybe, and then you have some beans later on. So the bigger consideration is probably the posse that the proteins show up with.

So, plant proteins have a ginormously awesome posse that come in with them through separate doors. Plant proteins have phytonutrients, micronutrients, lots of stuff. They also have fiber, and fiber never gets into the club. It is just the driver. It drops people off, and then it, like, goes out and cleans out your GI tract or feeds, donates itself to the microbiome in your colon.

And plant proteins come with more volume, so that's another distinctive factor about plant proteins. A cup of lentils is, like, 18 grams of protein. And two ounces of chicken is 18 grams of protein, or three and a half cups of quinoa is 18 grams of protein. So you can see the difference in the protein volume. You can see the difference in the volume.

And animal proteins come with more saturated fat sometimes. And red meat has also got a whole host of bad things that come along with it. But animal proteins may have more bioavailable iron, B12. Dairy sources have calcium. So there's different, different things that come with either of them.

I personally, if you have enough protein during the day, it doesn't matter where it came from. You're doing fine.

Pathak: That's so helpful, and I love the whole posse analogy because you're really thinking about who's coming with these foods. Help us think through someone who wants to make up their deficit or their total amount, and they're like, "Oh, let me look for some of these trendy high-protein foods or shakes."

Is that an option to make up the dietary need that we talked about, to make up that math? I know whole foods are better, per our conversation, but how do you help people think about utilizing those sources as part of their plan to get to their protein intake number?

Oppezzo: Yeah. I mean, just like you said, it's who it comes with, right? So if your protein's in yogurt, it's gonna come with some probiotics and some calcium. But let's say you're doing all these whole food sources and you're just not hitting your amount. You're getting like 60 grams a day.

You are not hitting the amount to 1.2 grams on that lower end per kilogram of body weight. Yeah, I think that's fine to have shakes, you know, and add stuff in. And in fact, I have my mom do that. And some people, as I said, they eat less and they chew less as they get older.

And maybe that's just really helpful, and that's totally fine. You're still a good person. I mean, for me, when I travel and I'm running around all day and I can't break for a meal, you know, I would not live without some shakes or bars because they're convenient and they help me at least eat something.

And also, I'm pre-diabetic, so I have very slow, not-listening insulin. So when I go to the movies, for example, and I want popcorn, I used to get, you know, my alarm would go off, and my popcorn, for my body—not everybody, for my body—it just spikes up my blood sugar. So I will have a protein bar before the popcorn.

And I'm not fooling myself to be like, "Ah, this protein bar is making me healthy." It's just like, actually, I just wanna slow down the absorption of my popcorn that I want to enjoy. So sometimes I use it strategically that way. So I have no problem if you're getting your vitamins, minerals, fiber, phytochemicals from this great diet and you don't hit your protein levels. Yeah, have a protein powder and put it in your coffee.

Pathak: So then let's talk about what the healthy plate should look like. So it's not just about protein. You mentioned many other nutrients that we need to be thinking about as well, all working in harmony to optimize our dietary pattern. So how should people think about balancing protein with all the other important nutrients?

Oppezzo: Yeah. I'm really sad because back in the day we had the dietary guidelines. I'm not saying everybody follows the dietary guidelines, but there was this image that was great. It was MyPlate. And you would look at your plate, and half should be veggies or fruit, a quarter-ish could be some decent source of protein, which could be tofu, lentils, or chicken.

And then a quarter-ish is like an intact whole grain, like brown rice or oats, and that's, like, pretty happy. So if... I like to tell people, kind of look at the—not like we sit down with plates anymore, but if we did, kind of look at, like, most of it. That should be the base. Or if you go to a place and build a bowl, right?

The base should be vegetables and fruit. And then add half and half for the other stuff. And I mean, we need carbohydrates. We threw them out with the bathwater, and especially if we're active, we do need carbohydrates. Your muscles run on glycogen. You need fats also for hormone production and vitamin absorption and other things, so we need fiber, which really only comes from carbohydrate sources, for blood sugar regulation and for gut health.

So we need those other things. We can't just eat protein. And we treat nutrition, I think, as if it's all about one micronutrient or macronutrient of the week, and then we have this most-wanted list. But I think that we're like, "These are the bad foods," or "These are the bad things," and then, "These are the good foods," and we give all this morality to food. And I think that's not the way we should approach diet or nutrition or healthy eating.

I think it's more vibes. And our body is pretty robust and has a pretty big capacity to adapt to a lot of different forms of eating and diets. I mean, the Alaskan Native diet does not have any fruits or vegetables, really, because it's so expensive to get them up there or grow them up there. But their healthy fats from seal and walrus and salmon and fish—it's just—they have a really heart-healthy diet.

So I don't think there's one size fits all, and we shouldn't think that certain foods are bad and certain foods are good. I think we should just think of, like, what are the best forms of fuel for my body, and not be very rigid about it.

Pathak: You have given us so much helpful, actionable information today, so I am so thankful. But as we come to the close of our time together, I'd love to just hand the floor to you, because I know that it can be overwhelming. There can be so much conflicting information online around protein goals, and it just can feel very difficult.

So I'd love to hand the floor to you to just end with advice directly to our audience around some examples to get started on this healthful journey, especially if you are really focusing or thinking about your protein intake.

Oppezzo: Helpful takeaways. Okay, so broken record, but are you doing some form of strength training? If not, start there. That matters way more than your exact protein number, and anything is better than nothing, and effort matters more than how much you're lifting. So make it hard; it doesn't have to necessarily be heavy.

So start there. And that can even just be body weight squats till you're tired.

Number two, I'd say, is are you getting a decent source of protein at most meals? So something at breakfast, something at lunch, and something at dinner. And if yes, you're probably fine. Maybe if you wanna count it for a day, you can use, you know, like MyFoodData from the USDA or Cronometer is free.

You could just go online, like put in your food for a day. Don't obsess about it, just kinda figure it out to see, like, where you're at. And for more expert help if you need it, ask your provider to refer you to a dietician who is a trained expert in this area and studied only nutritional sciences for multiple years.

So they're great resources as well. But then number three is, after you've counted it for a day or two, don't over-obsess. The ef- effect size of food is so small compared to exercise, and this feels really bad because I'm a dietician at heart in my original training. But I think exercise is a little more important in terms of muscle, or a lot more important.

So don't stress out about hitting your numbers every day. If you go to bed and you get 80 grams instead of that 105 we talked about, you're okay. You'll be fine. You won't lose your quad muscle. Just don't do it for weeks and months at a time.

And finally, I think with just the sea of information out there and misinformation, follow experts, not the "I'm the only one who knows, and P.S. I sell things online." So what's scientific isn't always what sells, and moderation and stuff you've already heard before is really boring, and nobody clicks on it.

So scientific consensus, if something is science-backed with solid evidence from good research and multiple studies, and experts are agreeing, most likely everybody's kind of converging on this.

And it's also probably not a bestseller or very extreme. So good nutrition information, some good places: I like the Berkeley newsletter, Harvard Health newsletter, Nutrition Action is a great newsletter for good nutrition work, and following people like Stuart Phillips, like I said, Luke Van Loon, Christopher Gardner, Dahlia Perelman, both of those are at Stanford, Louise Burke, Fabio Comana.

A source I highly respect and recommend for nutrition and also help with how to actually bring healthy foods into your everyday life is Michelle Hauser. She's a doctor at Stanford, but she's also a chef, and she has a free culinary medicine program. So definitely recommend that to check that out. These are people that are experts in this area. They are doing the research that is basically what I am disseminating right now.

So this is where you can find good sources of information, spending your time watching or learning from these scientists rather than the clickbaiters out there.

Pathak: I am so, so thankful to you. This has been really so informative, and I just want to thank you so much for your time.

Oppezzo: Thanks so much for having me. This has been fun.

Pathak: Thank you so much for being with us today. We've talked with Dr Marily Oppezzo about all things protein. My key takeaways from this discussion are, first, yes, protein matters, but it's not the only thing that matters in our diet. Getting enough protein is important for maintaining muscle and supporting all of our organs and hormones, but it's just one piece of a bigger puzzle that includes strength training, adequate calories, and a balanced diet that includes fiber, fruits, vegetables, and healthy fats.

Second, the average adult needs moderate, not extreme, amounts of protein, and going far beyond that doesn't really add extra health or muscle benefits. Finally, as we always talk about, the focus should be on patterns and not perfection.

You don't need to track every gram forever or live on protein products. A quick check of your usual intake and then figuring out ways to add more protein where you might have gaps, like at breakfast or lunch or even dinner, and then consistently doing strength training will take you much farther than chasing exact numbers or trendy high-protein foods.

To find out more information about Dr Marily Oppezzo and her work, make sure to check out our show notes. Thank you so much for listening. Please take a moment to follow, rate, and review this podcast on your favorite listening platform. If you'd like to send me an email about topics you're interested in or questions for future guests, please send me a note at [email protected].

This is Dr Neha Pathak for the WebMD Health Discovered podcast.