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

0:00You're listening to Life Kit from NPR.

0:06Allison Aubrey:Hey, it's Marielle. 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.

0:18Marielle Segarra: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.

0:33Allison Aubrey: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.

1:12Marielle Segarra: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.

1:23Allison Aubrey: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.

1:41Allison Aubrey:Support for this podcast and the following message come from Wayfair. It's Wayday at Wayfair, where you can score the best deals in home and upgrade your space that work within your budget. And the best part? Everything ships fast and free during Wayday. Get up to 80 % off with fast and free shipping on everything. Head to Wayfair.com April 25th through the 27th to shop Wayday. That's W-A-Y-F-A-I-R dot com. Wayfair. Every style, every home. Support for NPR and the following message come from Jarl and Pamela Moan, thanking the people who make public radio great every day and also those who listen.

2:21Allison Aubrey:ICE has ramped up immigration operations across the country, but American citizens and legal residents have increasingly found themselves targeted. Their message was not subtle, right? They were saying, we see you, we can get to you whenever we want to. And it did scare me. How Americans pushing back on ice are getting caught up in a web of surveillance. The Sunday story from the Up First podcast. Listen now on the NPR app. Okay, Allison, is there a recommended amount for how much protein we all need every day?

2:53Marielle Segarra: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 weight each day. Now, I know that most of us in the US 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.

3:34Marielle Segarra: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.

3:41Allison Aubrey:OK, so let's say somebody weighs 150 pounds. What would they need?

3:46Marielle Segarra: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.

4:08Allison Aubrey: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.

4:22Marielle Segarra: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 grams of 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.

5:02Marielle Segarra: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

5:35Allison Aubrey:even if you don't eat animal products.

5:38Marielle Segarra: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 gotta eat meat to get all the protein. But that is just simply not true.

6:13Marielle Segarra: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.

6:58Marielle Segarra: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, Pajetnik 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.

7:34Allison Aubrey:Okay, so you mentioned that how much protein you need depends on your body weight, but on other factors too. What are those?

7:42Marielle Segarra: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 stress on the body, and then that stress can actually increase the amount of protein your muscles use. Here he is.

8:09Allison Aubrey: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.

8:20Marielle Segarra: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, you know, 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.

9:03Allison Aubrey:Support for NPR and the following message come from Jarl and Pamela Moan, thanking the people who make public radio great every day and also those who listen. All right, what about age? Does the amount of protein we need change based on how old we are?

9:20Marielle Segarra: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.

9:44Allison Aubrey: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.

9:56Marielle Segarra: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 maybe your body is telling you it's time to pay attention. So Philip says the remedy to this starts with physical movement.

10:22Allison Aubrey: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?

10:38Marielle Segarra: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 bodyweight 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.

11:23Marielle Segarra:And this can lead to a longer, healthier life.

11:27Allison Aubrey:Alison Aubrey, thank you so much for being here.

11:30Marielle Segarra:You're welcome. This is one of those topics where the science is actually pretty actionable once you cut through all the noise.

11:38Allison Aubrey:All right, time for a recap. Federal dietary 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.

12:21Allison Aubrey: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 CJ Rakulan. 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.

13:01Allison Aubrey:Engineering support comes from Stacey Abbott. Fact-checking by Andrea Lopez Cruzado. I'm Mariel Segarra. Thanks for listening.

13:13Allison Aubrey:This message comes from Capital One with the Venture X Card. Earn unlimited double miles, a$300 annual Capital One travel credit, and access to airport lounges. Capital One. What's in your wallet? Terms apply. Details at CapitalOne.com. This message comes from Grainger. For the ones who get it done, Grainger offers the professional-grade products you need to get the job done. With fast delivery and access to technical product experts ready to help you meet any challenge. Call, click Grainger.com, or just stop by. Support for NPR comes from the Sci-Sims Foundation. since 1985, supporting advances in science, education, and the arts towards a fairer, more just, and civil society.

13:58Allison Aubrey:More information is available at scisimsfoundation.org.