Thank you for this thoughtful piece. The current protein discussion often treats intake as a universal number to be optimized, but physiology rarely works that way.
In my own work on metabolic regulation, I increasingly see nutrient needs — including protein — as a function of system throughput rather than fixed recommendations. A body with high metabolic demand, active tissue turnover, and robust transport can utilize nutrients very differently than a system operating with lower throughput or regulatory constraints.
In that sense, the real question may not simply be “How much protein do humans need?” but rather “How much can a given metabolic system actually process and use at a given moment?”
This is why general recommendations are helpful starting points, but they may miss an important layer of biology: metabolic variability between individuals and across physiological states.
Conversations like this are valuable precisely because they move us away from one-size-fits-all nutrition and toward a more systems-based understanding of metabolism.
I agree. My aim is to try to counter the persuasive message we see everywhere that we must cram as much protein as possible down our throats.
The irony is that those being swayed by this message tend to be those who already get plenty of protein, while those who likely need more, particularly older adults, are not targeted by the marketing - not that the protein-supplemented ultra-processed foods being promoted are the protein solution for anyone.
This highlights the hidden gap between fitness and longevity. It is a great reminder that our nutritional goals should evolve just as much as our exercise routines do.
I have always been a very slim person and realized when I was quite young that eating protein helped to reduce my hunger pangs. As an adult I have realized that I have a gluten intolerance, low iron and low B12. Perhaps I craved protein because of my B12/iron deficiency.
You're right there, Jane. Fat and protein tend to make you feel full, while carbs, especially the refined carbs we typically snack on, make us hungry again soon afterwards.
You're theory piqued my curiosity, so I had a look to see if there's anything in the scientific literature about deficiencies promoting an appetite for more protein.
There's certainly evidence that being deficient in protein makes us want more protein-rich foods, and even that deficiency of one or more amino acids makes us crave precisely the foods that will fill that gap. What I couldn't find was any suggestion that being deficient in micronutrients makes us want more protein - but it's possible that that's just because no one has looked!
I’m so pleased you found it helpful, Valerie. There’ll be more issues about protein in the coming weeks as it’s such an important topic, and there’s so much misinformation around.
I'm in my 70's and my appetite is smaller than it used to be so I find one of the easiest ways to get 30-40g of protein in a glass is to make a shake or smoothie. I use unflavored pea protein powder - I buy it in 5 kg (11 lb) lots from a bulk supplier and that makes it way cheaper than buying the smaller sizes sold in stores. What I make is not simply a "protein shake" because I add about 20 ingredients, including nuts, seeds, frozen berries, dark cocoa powder, spices, veg powder, etc to get lots of different nutrients, and yes it tastes very good. You can also add pea protein powder to hummus, soups, stews, tomato sauce, etc to boost the protein content if you eat small meals. The protein powder is very convenient and easy to use because it doesn't change the flavor of other foods it just makes them thicker, unless you dilute it. I eat lots of vegetables and fruit so my protein portions of fish, meat, beans, etc are not big so that's why I like to also use pea protein powder as a supplement. Thanks Ben for another insightful and practical article.
I think that’s the best solution for many past their mid-sixties.
As you know, while around 20g of protein at a meal will trigger maximum muscle protein synthesis in our twenties and thirties, by our seventies it takes more like 34-40g, and it takes an awful lots of ‘real’ food to hit that amount of protein. Many, if not most people just can’t consume that much at one sitting. It’s especially important at breakfast to ‘switch off’ the muscle breakdown that inevitably occurs overnight.
Adding a protein powder to a shake, a smoothie, porridge, or whatever is a great way to hit those larger targets.
Thanks Ben. With the decrease in my appetite that's another reason why I like to grow and use foods that have a very high nutrient density, especially in powder form for protein and vegetables, so that they can be easily ad to shakes, soups, stews, sauces etc. Also there's no spoilage with powders. Of course I still like to eat fresh fruits, veggies, berries on a daily basis. We're starting to get more strawberries now and next week we'll be buying more strawberry plants.
I’m a little confused as the article doesn’t mention activity. I’m in my late 50s but lift 5x and run 30 miles a week. I would expect my protein needs would be much higher than the average male my age. Any thoughts on this pushback?
FWIW, most knowledgeable feedback I’ve received recently recommends a target of 0.8g per LB, not KG. Your article would suggest I’m 2.2x higher than needed.
Hi Ed. You’re right; I didn’t cover activity in this issue. There’s a great deal I didn’t cover as the idea is that each issue can be read over a coffee, so there was no way I could cover all aspects of protein. It’s a topic I’ll be revisiting often over the next few months as it’s really important, and there’s a great deal of misinformation sloshing around at the moment.
With all your exercise, you’ll need more calories than others who are less active, but our bodies can only use a certain amount of protein. For a young, healthy adult, it takes about 20g of protein at a single meal to fully trigger muscle protein synthesis. Beyond that the curve flattens out. You can enhance your muscle gains by consuming about 30g of carbs with your protein. That’s more effective than piling on more protein. By our seventies, we need much more protein to have the same effect, closer to 35-40g.
Some writers focused on bodybuilding and fitness have cited research suggesting that eating much higher amounts of protein may lead to small, incremental gains in muscle size. But it’s important to understand the context behind those claims.
Much of that research focuses on maximising muscle size for aesthetic or competitive goals, and is often backed by commercial interests in the supplement industry. It’s important to check the conflicts of interest section before taking those recommendations at face value.
That’s a valid pursuit for some, but it’s a very different objective from building and maintaining the strength and functional muscle needed for long-term health and independence. For most people, these extreme protein intakes aren’t necessary, may do little for long-term health, and could even shorten life expectancy as I discussed in this issue.
Many of the high protein influencers also push diets high in red meat and eggs as they’re protein rich, but these are independently associated with worse health outcomes.
As someone in your late fifties, you’re in that transitional zone where, at a population level, protein needs start to increase as our bodies become less efficient at using it. Hence the recommendation to hit around 1.2g/kg from our mid-sixties.
There’s so much nuance here, Ed. While high protein intakes are associated with worse long-term health, in those studies where the source of protein is recorded, the worse health outcomes are only seen with animal protein. Plant protein, even at higher levels, is associated with better health outcomes. So, I don’t think the protein is the issue. I suspect it’s like the saturated fat and especially the carcinogenic and pro-inflammatory chemicals produced when we cook meat at high temperatures. So, if you want to push your protein intake higher, I’d do with with plant protein.
It’s debatable how much difference it makes. In a 2020 meta-analysis, participants over 55 who supplemented a normal diet with protein supplements gained, on average, only 460g (16oz) more lean body mass than those who didn’t.
I think people will be arguing over this for years. Influencers and trainers insist we need lots more protein, while researchers looking at healthy long-term health recommend more modest amounts. Even the journal in which an article is published makes a difference: those published in sports-related journals have higher recommended protein intakes.
Thanks for the thoughtful reply...I appreciate the nuance and I agree that the topic is more complex than most influencers make it out to be.
A few thoughts as someone who can see 60 coming up fast, trains pretty hard, and is trying to balance performance with longevity:
First, on the “20g per meal” point, my understanding is that the muscle protein synthesis ceiling is not a hard cap but a dose-response curve influenced by body size, total lean mass, and training stimulus. At ~95kg and resistance training regularly, 20g may be meaningfully different for me than for a 65kg sedentary adult. Some of the more recent work suggests closer to ~0.4g/kg per meal may maximize the response in trained individuals, which for me would be materially higher.
Second, I’m less convinced that the “high protein shortens lifespan” conclusion is settled science. A lot of the epidemiology conflates high protein with high processed meat intake and overall poor dietary patterns. When total calories, body composition, metabolic health, and training load are accounted for, the signal seems less clear. Mechanistically, protein supports lean mass retention, metabolic health, bone density, and insulin sensitivity...all of which are strongly associated with healthspan.
I also wonder whether population-level recommendations sometimes underweight the needs of resistance-trained adults.
I completely agree that protein source matters. I tend to prioritize whole-food sources and am mindful of cooking methods. I’m open to increasing plant protein, though practically it’s harder to hit higher intakes without increasing total calories.
For me the real question for me is what optimizes strength, metabolic health, and functional capacity over the next 20–30 years. For the most part, I'm focused on maintaining muscle and performance deep into older age and periodically testing my performance in events (that I specifically train in advance). My new hero is Gene Dykes, who holds the world record for a 70 yo marathon. Met him over the holidays and he's a beast. He trains like I did in my 30s
Thanks again for your thoughtful response, I’m enjoying the discussion and learning a lot along the way. In the end, I think of this process as a series of experiments of n=1. As long as I don't do something catastrophically damaging, I should maintain my health span well into my 90s.
That graph will look different as we move from our fifties to our seventies as our muscles become more resistant to protein triggers. In study participants over 65, muscle protein synthesis was still increasing at 40g of protein.
I agree with your cynicism over the high protein = worse long-term health messaging as I mentioned in my last message. Remember that the data we’re looking at now reflects what people were eating twenty or thirty years ago. That’s before the current craze for high-protein everything - most of that being whey protein. Back then, people getting the most protein likely ate lots of red meat, processed meat, eggs, etc, all of which are independently associated with worse health outcomes, some/much of which is likely due to those chemicals produced at high temperature cooking.
However, there’s still much we don’t fully understand. For example animal protein triggers the release of insulin-like growth factor 1 (IGF-1) which has been linked to cancer growth. Dairy protein has been shown to raise IGF-1 levels, so might the current craze for protein shakes and adding whey protein to all manner of ultra-processed foods lead to higher cancer rates? For now, we only have associations, and personal factors play a big role; I just throw it in as a potential concern for pushing excess protein on people at the population level.
From what you’ve told me, you’re far from the population norms reflected in those studies. You’re exercising far more than the average person, taking in both aerobic and resistance exercise. You’re careful with what you eat, and I suspect you have all manner of other healthy habits, along with being well educated and likely have the financial means to eat well and get appropriate preventative healthcare.
I suspect you’ve got exercise + protein well covered. Your biggest gains likely come from other corners of your life - a healthy symbiosis with your body clock, sleep hygiene, getting 200g of fruit a day and 15g of nuts, using extra virgin olive oil as your default fat, and using less plastic in the kitchen!
Thanks for a more rational approach to protein. Seems lately grocery shopping has labels figuratively slapping you in the face about protein. Even a cookie hyping 16g plant based protein and 10 g fiber. However, looking that the nutrition label a cookie (large size one) has 64g carbo with 22 g of added sugar (not hfcs). Despite the high fiber 10 g, not a healthy cookie.
Across the pond here, we now have a dietary guideline featuring an upside down pyramid. Protein is more geared toward the livestock industries (mainly cattle). Not even a top protein source according to the table you provided.
Surprised you didn't mention the effect of senescence in digestiion & protein. Protein digestion may become less efficient, affecting the body's ability to break down and utilize proteins. Though you did allude to chronic kidney disease, diabetes.
Thanks! You’re right, protein has become a fad rather than an evidence-based nutritional component. You’re horribly unhealthy high-protein cookie is a prefect example of where that inevitably leads. Loads of people will be happily munching on those thinking they’re doing themselves a favour!
There’s a great deal I didn’t cover in this issue. The idea is that they can be read over a coffee, so there was no way I could cover all aspects of protein. It’s a topic I’ll keep coming back to, and how our protein needs change as we get older is a vital topic I’ll be revisiting.
(The pyramid is not the only thing that’s upside down at your HHS)
Thank you for this thoughtful piece. The current protein discussion often treats intake as a universal number to be optimized, but physiology rarely works that way.
In my own work on metabolic regulation, I increasingly see nutrient needs — including protein — as a function of system throughput rather than fixed recommendations. A body with high metabolic demand, active tissue turnover, and robust transport can utilize nutrients very differently than a system operating with lower throughput or regulatory constraints.
In that sense, the real question may not simply be “How much protein do humans need?” but rather “How much can a given metabolic system actually process and use at a given moment?”
This is why general recommendations are helpful starting points, but they may miss an important layer of biology: metabolic variability between individuals and across physiological states.
Conversations like this are valuable precisely because they move us away from one-size-fits-all nutrition and toward a more systems-based understanding of metabolism.
I agree. My aim is to try to counter the persuasive message we see everywhere that we must cram as much protein as possible down our throats.
The irony is that those being swayed by this message tend to be those who already get plenty of protein, while those who likely need more, particularly older adults, are not targeted by the marketing - not that the protein-supplemented ultra-processed foods being promoted are the protein solution for anyone.
This highlights the hidden gap between fitness and longevity. It is a great reminder that our nutritional goals should evolve just as much as our exercise routines do.
I have always been a very slim person and realized when I was quite young that eating protein helped to reduce my hunger pangs. As an adult I have realized that I have a gluten intolerance, low iron and low B12. Perhaps I craved protein because of my B12/iron deficiency.
You're right there, Jane. Fat and protein tend to make you feel full, while carbs, especially the refined carbs we typically snack on, make us hungry again soon afterwards.
You're theory piqued my curiosity, so I had a look to see if there's anything in the scientific literature about deficiencies promoting an appetite for more protein.
There's certainly evidence that being deficient in protein makes us want more protein-rich foods, and even that deficiency of one or more amino acids makes us crave precisely the foods that will fill that gap. What I couldn't find was any suggestion that being deficient in micronutrients makes us want more protein - but it's possible that that's just because no one has looked!
This is enormously helpful. Thank you!
I’m so pleased you found it helpful, Valerie. There’ll be more issues about protein in the coming weeks as it’s such an important topic, and there’s so much misinformation around.
I'm in my 70's and my appetite is smaller than it used to be so I find one of the easiest ways to get 30-40g of protein in a glass is to make a shake or smoothie. I use unflavored pea protein powder - I buy it in 5 kg (11 lb) lots from a bulk supplier and that makes it way cheaper than buying the smaller sizes sold in stores. What I make is not simply a "protein shake" because I add about 20 ingredients, including nuts, seeds, frozen berries, dark cocoa powder, spices, veg powder, etc to get lots of different nutrients, and yes it tastes very good. You can also add pea protein powder to hummus, soups, stews, tomato sauce, etc to boost the protein content if you eat small meals. The protein powder is very convenient and easy to use because it doesn't change the flavor of other foods it just makes them thicker, unless you dilute it. I eat lots of vegetables and fruit so my protein portions of fish, meat, beans, etc are not big so that's why I like to also use pea protein powder as a supplement. Thanks Ben for another insightful and practical article.
I think that’s the best solution for many past their mid-sixties.
As you know, while around 20g of protein at a meal will trigger maximum muscle protein synthesis in our twenties and thirties, by our seventies it takes more like 34-40g, and it takes an awful lots of ‘real’ food to hit that amount of protein. Many, if not most people just can’t consume that much at one sitting. It’s especially important at breakfast to ‘switch off’ the muscle breakdown that inevitably occurs overnight.
Adding a protein powder to a shake, a smoothie, porridge, or whatever is a great way to hit those larger targets.
Thanks Ben. With the decrease in my appetite that's another reason why I like to grow and use foods that have a very high nutrient density, especially in powder form for protein and vegetables, so that they can be easily ad to shakes, soups, stews, sauces etc. Also there's no spoilage with powders. Of course I still like to eat fresh fruits, veggies, berries on a daily basis. We're starting to get more strawberries now and next week we'll be buying more strawberry plants.
I’m a little confused as the article doesn’t mention activity. I’m in my late 50s but lift 5x and run 30 miles a week. I would expect my protein needs would be much higher than the average male my age. Any thoughts on this pushback?
FWIW, most knowledgeable feedback I’ve received recently recommends a target of 0.8g per LB, not KG. Your article would suggest I’m 2.2x higher than needed.
Thanks in advance
Hi Ed. You’re right; I didn’t cover activity in this issue. There’s a great deal I didn’t cover as the idea is that each issue can be read over a coffee, so there was no way I could cover all aspects of protein. It’s a topic I’ll be revisiting often over the next few months as it’s really important, and there’s a great deal of misinformation sloshing around at the moment.
With all your exercise, you’ll need more calories than others who are less active, but our bodies can only use a certain amount of protein. For a young, healthy adult, it takes about 20g of protein at a single meal to fully trigger muscle protein synthesis. Beyond that the curve flattens out. You can enhance your muscle gains by consuming about 30g of carbs with your protein. That’s more effective than piling on more protein. By our seventies, we need much more protein to have the same effect, closer to 35-40g.
Some writers focused on bodybuilding and fitness have cited research suggesting that eating much higher amounts of protein may lead to small, incremental gains in muscle size. But it’s important to understand the context behind those claims.
Much of that research focuses on maximising muscle size for aesthetic or competitive goals, and is often backed by commercial interests in the supplement industry. It’s important to check the conflicts of interest section before taking those recommendations at face value.
That’s a valid pursuit for some, but it’s a very different objective from building and maintaining the strength and functional muscle needed for long-term health and independence. For most people, these extreme protein intakes aren’t necessary, may do little for long-term health, and could even shorten life expectancy as I discussed in this issue.
Many of the high protein influencers also push diets high in red meat and eggs as they’re protein rich, but these are independently associated with worse health outcomes.
As someone in your late fifties, you’re in that transitional zone where, at a population level, protein needs start to increase as our bodies become less efficient at using it. Hence the recommendation to hit around 1.2g/kg from our mid-sixties.
There’s so much nuance here, Ed. While high protein intakes are associated with worse long-term health, in those studies where the source of protein is recorded, the worse health outcomes are only seen with animal protein. Plant protein, even at higher levels, is associated with better health outcomes. So, I don’t think the protein is the issue. I suspect it’s like the saturated fat and especially the carcinogenic and pro-inflammatory chemicals produced when we cook meat at high temperatures. So, if you want to push your protein intake higher, I’d do with with plant protein.
It’s debatable how much difference it makes. In a 2020 meta-analysis, participants over 55 who supplemented a normal diet with protein supplements gained, on average, only 460g (16oz) more lean body mass than those who didn’t.
I think people will be arguing over this for years. Influencers and trainers insist we need lots more protein, while researchers looking at healthy long-term health recommend more modest amounts. Even the journal in which an article is published makes a difference: those published in sports-related journals have higher recommended protein intakes.
Thanks for the thoughtful reply...I appreciate the nuance and I agree that the topic is more complex than most influencers make it out to be.
A few thoughts as someone who can see 60 coming up fast, trains pretty hard, and is trying to balance performance with longevity:
First, on the “20g per meal” point, my understanding is that the muscle protein synthesis ceiling is not a hard cap but a dose-response curve influenced by body size, total lean mass, and training stimulus. At ~95kg and resistance training regularly, 20g may be meaningfully different for me than for a 65kg sedentary adult. Some of the more recent work suggests closer to ~0.4g/kg per meal may maximize the response in trained individuals, which for me would be materially higher.
Second, I’m less convinced that the “high protein shortens lifespan” conclusion is settled science. A lot of the epidemiology conflates high protein with high processed meat intake and overall poor dietary patterns. When total calories, body composition, metabolic health, and training load are accounted for, the signal seems less clear. Mechanistically, protein supports lean mass retention, metabolic health, bone density, and insulin sensitivity...all of which are strongly associated with healthspan.
I also wonder whether population-level recommendations sometimes underweight the needs of resistance-trained adults.
I completely agree that protein source matters. I tend to prioritize whole-food sources and am mindful of cooking methods. I’m open to increasing plant protein, though practically it’s harder to hit higher intakes without increasing total calories.
For me the real question for me is what optimizes strength, metabolic health, and functional capacity over the next 20–30 years. For the most part, I'm focused on maintaining muscle and performance deep into older age and periodically testing my performance in events (that I specifically train in advance). My new hero is Gene Dykes, who holds the world record for a 70 yo marathon. Met him over the holidays and he's a beast. He trains like I did in my 30s
Thanks again for your thoughtful response, I’m enjoying the discussion and learning a lot along the way. In the end, I think of this process as a series of experiments of n=1. As long as I don't do something catastrophically damaging, I should maintain my health span well into my 90s.
Hi Ed.
You’re right, the response to protein dose at a meal is a curve, but for younger adults at least, that curve flattens off around 20g. I showed the graph in a Medium article about what triggers muscle protein synthesis. If you’ve not seen that one, you might find it interesting. [https://medium.com/in-fitness-and-in-health/are-you-missing-the-crucial-protein-triggers-to-build-and-keep-muscle-an-md-phd-explains-bf2fdc288ee9?sk=9e445688e50d27be883c663d1df15f31]
That graph will look different as we move from our fifties to our seventies as our muscles become more resistant to protein triggers. In study participants over 65, muscle protein synthesis was still increasing at 40g of protein.
I agree with your cynicism over the high protein = worse long-term health messaging as I mentioned in my last message. Remember that the data we’re looking at now reflects what people were eating twenty or thirty years ago. That’s before the current craze for high-protein everything - most of that being whey protein. Back then, people getting the most protein likely ate lots of red meat, processed meat, eggs, etc, all of which are independently associated with worse health outcomes, some/much of which is likely due to those chemicals produced at high temperature cooking.
However, there’s still much we don’t fully understand. For example animal protein triggers the release of insulin-like growth factor 1 (IGF-1) which has been linked to cancer growth. Dairy protein has been shown to raise IGF-1 levels, so might the current craze for protein shakes and adding whey protein to all manner of ultra-processed foods lead to higher cancer rates? For now, we only have associations, and personal factors play a big role; I just throw it in as a potential concern for pushing excess protein on people at the population level.
From what you’ve told me, you’re far from the population norms reflected in those studies. You’re exercising far more than the average person, taking in both aerobic and resistance exercise. You’re careful with what you eat, and I suspect you have all manner of other healthy habits, along with being well educated and likely have the financial means to eat well and get appropriate preventative healthcare.
I suspect you’ve got exercise + protein well covered. Your biggest gains likely come from other corners of your life - a healthy symbiosis with your body clock, sleep hygiene, getting 200g of fruit a day and 15g of nuts, using extra virgin olive oil as your default fat, and using less plastic in the kitchen!
Thanks for a more rational approach to protein. Seems lately grocery shopping has labels figuratively slapping you in the face about protein. Even a cookie hyping 16g plant based protein and 10 g fiber. However, looking that the nutrition label a cookie (large size one) has 64g carbo with 22 g of added sugar (not hfcs). Despite the high fiber 10 g, not a healthy cookie.
Across the pond here, we now have a dietary guideline featuring an upside down pyramid. Protein is more geared toward the livestock industries (mainly cattle). Not even a top protein source according to the table you provided.
Surprised you didn't mention the effect of senescence in digestiion & protein. Protein digestion may become less efficient, affecting the body's ability to break down and utilize proteins. Though you did allude to chronic kidney disease, diabetes.
Keep up the good work!
Thanks! You’re right, protein has become a fad rather than an evidence-based nutritional component. You’re horribly unhealthy high-protein cookie is a prefect example of where that inevitably leads. Loads of people will be happily munching on those thinking they’re doing themselves a favour!
There’s a great deal I didn’t cover in this issue. The idea is that they can be read over a coffee, so there was no way I could cover all aspects of protein. It’s a topic I’ll keep coming back to, and how our protein needs change as we get older is a vital topic I’ll be revisiting.
(The pyramid is not the only thing that’s upside down at your HHS)
It was useful to compete the audit. (My protein intake is fine, but I probably ate too much protein when I was younger.)
Thanks, Jane. I’m glad to hear you found it useful. Can I ask what drove the high protein intake when you were younger?
Thank you!