Life Kit - Protein is personal. Here's how to calculate your optimal intake

Episode Date: April 6, 2026

Protein is having a moment. Coffee chains are adding it into lattes. Many snack companies are labeling their products as high-protein. But how much protein do you really need? Host Marielle Segarra talks with NPR health correspondent Allison Aubrey about the different factors to consider when planning your protein intake.Follow us on Instagram: @nprlifekitSign up for our newsletter here.Have an episode idea or feedback you want to share? Email us at [e-mail] the show and listen to it sponsor-free by signing up for Life Kit+ at plus.npr.org/lifekitTo manage podcast ad preferences, review the links below:See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Life Kit from NPR. Hey, it's Mariel. Today on the show, we're talking about protein. You may know that we need it to stay alive and that it allows us to build and repair our muscle tissue. But it does a lot more. It also makes the enzymes your body uses to digest food. It produces the antibodies that help your immune system fight off viruses and infection. So proteins are really kind of workhorse molecules.

They're absolutely essential. This is Alison Aubrey, a science and health correspondent at NPR. She's been reporting on protein lately because protein, it seems, is having a moment. In particular because health secretary Robert F. Kennedy Jr. is a big proponent. In fact, he says he personally only eats meat, fish, and fermented foods like yogurt. Though I should say the federal government issued new dietary guidelines for Americans this year. And they do recommend eating plenty of fruits, vegetables, and whole grains.

Back to the protein question, though. Allison wanted to strip away the noise and give people a clear sense of how much protein they actually need a day. Because the answer isn't exactly the same for everyone. Your optimal protein intake depends on who you are. And some key factors include how active you are, your age, and your body weight. On this episode of Life Kit, a personalized protein roadmap. We'll talk about how many grams of protein you should aim for each day

based on different factors, and we'll also talk about how to meet those goals. You don't have to be a carnivore. That's after the break. Okay, Allison, is there a recommended amount for how much protein we all need every day? Well, the numbers have actually just been updated this year, which is part of why we are talking about this right now. So the federal dietary guidelines now recommend a higher daily intake, somewhere between 1.2 to 1.6 grams of protein per kilogram of body. each day. Now, I know that most of us in the U.S. don't think in terms of kilograms, so you can use an online calculator to make the conversion and calculate how much protein you need. I'll say more about that in a moment. But the bottom line here is that this is a meaningful bump up from prior guidelines. And Rachel Pogednik, who has studied this for a very long time, told me she's on

board with this change. That's the ideal range. I think that's why these guidelines were updated. And I think this is what the research has been really showing for quite some time now. Okay, so let's say somebody weighs 150 pounds, what would they need? Yes, absolutely. It can be complicated, but let's make it concrete here. So you take that 150 pound person, they need roughly 82 grams of protein a day on the low end and up to about 109 grams on the high end. And this is why body weight even enters into the equation. You're calculating how much protein you need based on weight. That feels like a lot to me. But maybe it's because I don't eat a ton of meat or I don't eat meat all the time.

I'm trying to figure out how this would actually look on a plate. Sure. Well, let me just walk you through. I've thought a little bit about this in preparation. And here's one way to think about hitting that range for a day, for that 150-pound person. Okay, breakfast. A cup of Greek yogurt, that's about 17, maybe 20, protein right there. Add some nuts, a handful of nuts. You've got another four or five grams,

depending on the type of nut. So you're starting the day with roughly 25 grams, you know, before you've left the house. Now, for lunch, think a cup of cooked lentils. That's about 18 grams. Add some vegetables. For instance, a cup of broccoli has about 2.5 grams of protein, give or take. Now you've got a solid meal and you've gotten more protein maybe than you realized. A snack, a handful, of almonds or some, say, hummus with veggies, that's around five more grams. And for dinner, a meal that includes, say, a four-ounce chicken breast, which is about 35 grams of protein, well, then you add that all up and you are right in the target range. Now, if you're not a meat eater, you can swap in tofu at the dinner meal, which is about three to four grams of protein per ounce

or other kinds of beans. Okay, so you can get enough protein even if you don't eat animal products. Yes, you can. This is one of the more common questions, and the science is actually pretty clear, pretty reassuring on this. You can get everything you need from plant-based sources. Here's Rachel Pajednik again. The literature shows unequivocally that you can get enough protein and all of the essential amino acids from a plant-based diet as well as a diet that includes meat or meat-derived products. So, you know, sometimes people conflate their personal preferences or politics, with the science and say, oh, you know, you got to eat meat to get all the protein. But that is just simply not true.

Is the protein you get from plants the same as the protein you'd get from meat? So just a little bit of context first on why people sometimes worry that they won't get enough protein from plant sources. There are about 20 amino acids that the body uses as building blocks for protein. And nine of them are considered essential. What this actually means is that your body can't manufacture them. on its own. So we've got to get these through the food and drinks we consume. So animal products like meat, eggs, dairy, typically supply sufficient amounts of all nine of these amino acids.

And some plant sources like soybeans, which is used to make tofu, are also considered, quote unquote, complete proteins. But many plant foods have lower proportions of specific amino acids. So they are thought to be incomplete proteins. So really this is the key message. If you eat a wide variety of plant foods to get enough of all of these amino acids, Pajednik says this is possible. I mean, think vegetables, fruits, whole grains, beans, legumes, you can kind of mix and match and cover the full spectrum.

And, you know, if you're not getting everything that you need from food, then, of course, there's the protein powders and the supplements. Okay, so you mentioned that how much protein you, you need depends on your body weight, but on other factors too. What are those? Let's talk about activity level, because this is important. I spoke to a researcher named Stuart Phillips. He's at McMaster University in Canada. He studies skeletal muscle health. And he told me that activity is one of the key drivers of how much protein you need. When you exercise, you're creating a stress on the body, And then that stress can actually increase the amount of protein your muscles use.

Here he is. When you eat more protein, you can take more up. You make more new muscle proteins. And if you like, compensate for the stress of the exercise. So there's this very symbiotic relationship between movement and protein, where exercise kind of creates the need for muscle repair. And protein provides the fuel to rebuild. to stay strong. This is why many weightlifters and competitive athletes have long been told

to eat on the high end of the protein recommendations. So really the key message here is if you're working out regularly, you may want to be closer to that 1.6 grams per kilogram mark, that high end of the new guidelines as opposed to the lower end. We will have more life kit after the break. All right. What about age? Is the amount of protein we need change based on how old we are? So protein needs actually increase with age because the body becomes kind of less efficient at processing protein.

And so bumping up intake to that higher end of the recommended range can be beneficial. And you know, these age-related changes, a lot of people just don't see them coming. And by the time they notice, they may have already lost a little ground. Here's Stuart Phillips again. People begin to lose muscle mass somewhere in their 30s and 40s, and you don't notice it until maybe your 50s or your 60s, and all of a sudden you can't do one thing or another. So, you know, maybe you go to lift your suitcase when you're on the airplane and it's hard to get it into the overhead bin, or you're carrying your groceries from the car and it's more challenging. You have to take two trips. So these are inconveniences, but they are also signals that your muscle mass has begun quietly declining and, you know,

maybe your body is telling you it's time to pay attention. So Phillips says the remedy to this starts with physical movement. If you exercise, particularly weightlifting or resistance exercise, that's going to slow muscle loss down. And that then in combination with more protein would be even more effective. Anything else we need to think about as we're figuring out our protein needs? You know, I think there is something else. Women, I mean, women tend to eat less protein compared to men and also tend to do less strength training, at least historically. I know as a Gen X woman, I was late to the strength training memo, and many women have long prioritized sort of cardio over strength training. So the key message here is really simple. It isn't about being extreme

or lifting heavy weights five days a week. I mean, even just adding some resistance training, things like body weight exercises, you know, lightweights, resistance bands, two to three times a week for say a half an hour, combined with bumping up your protein toward that higher end of the recommended range can help you maintain muscle mass, like help you stay strong. And this can lead to a longer, healthier life. Alton Aubrey, thank you so much for being here. You're welcome. This is one of those topics where the science is actually pretty actionable once you cut through all the noise. All right, time for a recap. Federal dietary guidelines. guidelines recommend that adults get between 1.2 and 1.6 grams of protein per kilogram of body weight

every day. Since most of us in the U.S. don't think in kilograms, probably the easiest thing to do is use an online calculator to convert your weight into pounds and then use that number to calculate your protein needs. Say you weigh 150 pounds. That's about 68 kilograms. So you'd want to eat between about 82 and 109 grams of protein a day. If you're working out a lot, especially strength training, you'll want to aim for the top of that range. And remember that we start to lose muscle mass in our 30s and 40s. So if you're in that range or older, make strength training and eating protein a priority. Oh, one more quick point. These recommendations are intended for the general public, but if you have a health condition, you want to talk to your doctor. For instance,

people with chronic kidney disease might be advised to eat less protein. This episode of Life Kit was produced by Claire Marie Schneider. Our digital editor is Malika Grieb, and our visuals editor is C.J. Rekulon. Megan Cain is our senior supervising editor, and Beth Donovan is our executive producer. Our production team also includes Andy Tagle, Margaret Serino, Sylvie Douglas, and Mika Ellison. Engineering support comes from Stacey Abbott. Fact-checking by Andrea Lopez Crusado. I'm Mariel Segarra. Thanks for listening.