Hey Vegan, where do you get your protein?
If you’ve been eating a vegan or plant-based diet long enough, you’ve probably heard that question enough times to make you start hemorrhaging muscles from your eyes.
Some of us are so sick of others’ concern over our protein needs, and so used to telling inquiring people that there’s actually plenty of protein in whole plant foods, that we may have long ago stopped considering whether or not we’re actually failing to get enough protein for optimal health and athletic performance.
And if we have, there’s good reason for it: virtually everyone in the plant based movement keeps telling us protein isn’t that important.
Vegan Protein Bellwethers
At first glance, it seems reasonable that everyone is very blasé about the idea of needing more protein.
After all, the Institute Of Medicine’s recommended dietary allowance (RDA) for protein, which is designed to meet the needs of 97 to 98% of the population – even athletes and the genetically disadvantages – is just .80 grams per kilogram of body weight per day (.36 grams per pound). This is doable on a whole foods vegan diet without any supplements or a big attention to protein intake. And if you eat a lower protein raw vegan diet, you can likely still hit the USDA’s estimated average requirement for protein (how much protein the average person requires) at just .66 grams of protein per kg of bodyweight.1.
For years, the big names in the vegan/plant-based movement, including scientists, athletes, and doctors, have more or less held the line that the RDA covers all our protein needs.
Although he previously suggested a higher protein target, vegan bodybuilder Robert Cheeke, author of Shred It, now cities Campbell in saying that 5-10% of calories from protein is good enough.
Dr. John McDougall, author of The Starch Solution, allows for slightly more protein, suggesting that 7-15% of calories is ideal, but doesn’t emphasize that being on the higher end of that scale is better.
On the raw food side of things, Dr. Doug Graham, author of the 80/10/10 Diet, caps intake at a maximum of 10% of calories from protein, with a common whole-diet protein range for his suggested foods coming out to 4 to 7% of calories from protein.
Even I’ve made it clear that I’ve thrived athletically at a protein intake of .60-70 grams/kg, and pointed out a study demonstrating non-athletes can get stronger and build muscle while eating just 0.6 grams per kg and doing some strength training.
In other words, the general consensus in the plant-based-diet movement is that that the RDA will provide everyone with enough protein for optimal health and function.
The Changing Reality Of Protein Research
When I started eating a vegan diet around 2003-2004, I reviewed the current protein research, checked out the RDA recommendations, and determined that there was no evidence that I needed to care about my protein intake as long as I stuck to whole plant foods – it was beyond simple to meet all my needs.
But 2003 was a long time ago, and science moves on. Starting in the late 2000s, anyone who was keeping an eye on nutrition research began noticing the steady appearance of studies calling into question the USDA’s protein target, particularly for certain populations.
In 2010, a group of researchers (including one of the three researchers who came up with the RDA) published a paper 3 that concluded the methodology used to set the RDA was flawed, and that actual human protein requirements for optimal function were likely significantly higher. The paper suggested that the estimated average requirement (how much the average person needs) was actually between .91 and .93 g/kg/day, and the the RDA (Designed to cover 97% to 98% of the population) should be set at 1.0 – 1.2 g/kg/day.
So a 170 lb man would have to take in at least 92.4 grams of protein to hit this corrected RDA, or roughly 16% of his caloric intake if he’s a moderately active non-athlete. If he’s trying to lose weight and cutting his caloric intake down, protein would have to be a bigger percentage of his intake.
The researchers write: “These new values are approximately 40% higher than the current recommendations, and therefore, there is an urgent need to reassess recommendations for protein intake in adult humans.”
Of course, one study should never be the basis of a paradigm shift. It’s only when we see the same results again and again that we should start to draw conclusions…but that’s exactly what we’ve seen
The Higher Protein Evidence Builds Up
Vegans Meeting The RDA Are Frequently Out Of Nitrogen Balance:
Considering how much ridiculous protein-based criticism plant-based diets have gotten over the years, it’s strange that there have been no nitrogen balance studies done on long-term vegans to investigate whether or not an adaptation occurs allowing vegans to reach nitrogen balance at lower protein intakes.
What is nitrogen balance, and why is it important?
Positive nitrogen balance occurs when the intake of nitrogen into the body (in the form of the amino acids which make up protein) is greater than the loss of nitrogen from the body (urine, feces). Positive nitrogen balance is observed during periods of growth, tissue repair, and pregnancy. Negative nitrogen balance correlates with periods of no/little growth and muscle breakdown.
If you’re in a state of positive nitrogen balance, you’re probably capable of putting on muscle, healing rapidly, mounting a strong immune response, and generally thriving. If you’re in a negative nitrogen balance, your ability to do this is more limited.
In terms nitrogen balance regarding vegans, we have no long-term studies of established vegans, which is admittedly a problem for drawing conclusions. All we’ve got are a few studies looking at people put on vegan diets for short periods of time (mostly not recently conducted). Many of these find that vegans aren’t in nitrogen balance unless they’re consuming a higher-than-RDA protein intake.
This one found vegans to be mostly out of nitrogen balance at .50 g/kg/day, which is what some people on raw food diets might consume if they’re not very physically active. 4
Another study put people on vegan diets for three weeks at .91 g/kg of protein per day. Only 9 out of 12 of the participants were in nitrogen balance, showing how genetics, lifestyle factors, and perhaps adaptation efficiency can vary our individual requirements 5
An almost-vegan diet (a small amount of milk was added) was used in this study, and it found 1 g of protein/kg put seven out of eight participants into nitrogen balance.6
So it appears that the closer plant-based dieters get to the the 1.0 – 1.2 g/kg target presented in the study mentioned above, the more likely they are to be in nitrogen balance.
For those of you who question a lack of long-term nitrogen balance studies on vegans, or the use of nitrogen balance studies more broadly, I’ll be addressing that below.
Your Antioxidant Defenses Are Impaired While Eating The RDA
Your body is constantly fighting against oxidative stress, which occurs when the production and intake of free radicals overwhelms your body’s antioxidant defenses. When the body doesn’t have enough antioxidants on hand, your cells are damaged and the early stages of heart disease and cancer begin.
Although we take antioxidants in from fruits and vegetables, internally-produced antioxidants are the most important part of our free radical defense network, particularly the antioxidant glutathione.
Until recently it was believed that the RDA for protein would be enough to let the body generate all the antioxidants it needs, but a recent study has shown this to not be the case7.
Subjects were switched from an initial protein intake of 1.13 g/kg to .75 g/kg, or just below the RDA.
The body’s ability to produce glutathione declined significantly, and didn’t recover even when subjects were in nitrogen balance.
The researchers write that, “These changes in glutathione imply a reduced capability to withstand stress and potentially greater susceptibility to environmental challenges.”
The Protein RDA Leaves Athletes Behind
The Institute Of Medicine doesn’t give a higher protein target for athletes because they consider the RDA to be sufficient for 98% of the population, regardless of if they’re a bodybuilder, a marathon runner, or a couch potato. But athletic researchers never embraced the protein RDA because they had ample evidence that more protein is required for their subjects to reach nitrogen balance and other performance metrics.
In 2009, the American College of Sports Medicine, the American Dietetic Association, and Dietitians of Canada laid out the research which they felt supported higher protein intake for athletes in a jointly-issued paper 8.
Due to research into nitrogen balance, rates of muscle creation, and other athletic benchmarks, they set out these guidelines for protein:
- Endurance athletes: 1.2 to 1.4 g/kg/day
- Strength athletes: 1.2 to 1.7 g/kg/day, although they add that, “the amount of protein needed to maintain muscle mass may be lower for individuals who routinely resistance train because of more efficient protein use.”
How good is the evidence supporting these higher targets? In 2007, the International Society of Sports Nutrition characterized the scientific evidence supporting protein targets higher than the RDA for athletes as, “vast.”9.
“Protein intakes of 1.4 – 2.0 g/kg/day for physically active individuals is not only safe, but may improve the training adaptations to exercise training,” they wrote in their position statement.
More recent research has only reinforced these findings. For instance, to pick out a few studies among many:
One study found optimal results for strength athletes seems to occur at 1.7 to 2.2 g/kg 10
Researchers looking at women doing interval sprints found them to require at least 1.41 g/kg to meet their needs .11
Stronger Bones With More Protein:
Eating more protein than the RDA recommendation (1.4 g/kg) is associated with greater bone mineral density at most bone sites, and in particular a stronger lumbar spine, compared with merely hitting the RDA (0.8 g/kg) 12.
People Over 60 Do Better With More Protein:
A number of studies have found that the RDA is not sufficient to protect aging people from sarcopenia and bone loss, and have argued in favor of elderly people receiving more protein than the RDA. 13 Most suggest older people have protein intakes of at least 1.2 g/kg 14.
Total protein intake aside, merely eating more higher-protein foods in your diet, and not just relying on lower-protein fruits, vegetables, and grains, puts you at a much lower risk of a hip fracture if you’re older.
Among older vegetarians, eating legumes at least once a day reduced hip fracture risk by 64% compared with those who ate them once a week 15.
Double Checking Nitrogen Balance Studies:
Although nitrogen balance studies have long been considered the gold standard of protein requirement research, some people doubt the method’s validity for a number of reasons. For one, it’s hard and expensive to do nitrogen balance research, and there’s a signifiant possibility of error.
Subjects need to be put through 7-10 days of adaptation at each new protein level tested, and pretty much need to be locked up so that all urine and feces can be collected, and all food intake prepared and calculated.
However, a new method which “tags,” amino acids and traces them though the body has been found to be cheaper, easier to test for, and more accurate 16.
So if nitrogen balance studies weren’t an ideal way to check for protein requirements, this new method might yield different results. But it didn’t.
The new test has shown a 98%-of-population protein requirement of 1.09 g/kg/day. In other words, the new test results show human requirements to be very close to the reanalyzed nitrogen balance study mentioned above.
Why Haven’t You Heard About This?
The reason why studies showing the RDA to be outdated haven’t made headlines in the developed world is that it doesn’t affect most of the population.
The average protein intake in the United States is already 16% of calories (1.68 g/ kg), and ranges up to 23% of energy (2.4 g/kg) 17.
Most of the people who aren’t meeting the safe 1.09 g/kg figure in the developed world are non-athletes eating plant-based diets and avoiding legumes, people restricting their calorie intake or otherwise dieting, the elderly, and in particular, people eating raw food diets.
Why I’m Bringing This Up:
There are three reasons I’ve slowly changed my stance on protein:
- As more research has been conducted over the last decade, it’s become increasingly hard to consider the RDA adequate for most populations, and I don’t feel like its reasonable to ignore that for the sake of an ideology. The available data indicates that most people would benefit from more protein than they’d get on the RDA, or a laissez faire approach to a vegan diet, so I think it’s worth discussing.
- I’ve watched the new research about protein coming out for years, and had a desire to experiment with a higher protein intake, but couldn’t due to my colitis. It was only after I began my lectin reduction experiments that I was able to tolerate foods that were higher in protein. After about a decade of consuming just .55 to .65 g/kg, I increased my protein intake beginning in early 2016. For about six months I ate .80 g/kg (the RDA) and for more than a year now I’ve consumed 1.2 g/kg. I noticed little/no difference on .80 g/kg, but a lot of difference on 1.2 g/kg. I will be talking more about my experiments with higher protein intake in future articles and videos.
- At the end of the day, I deal with a lot of coaching clients. They’re usually not young, healthy, endurance athletes. Most of the people who come to me for help have serious health problems, are struggling with their weight, or are older individuals. In the case of older individuals in particular, I think it’s irresponsible to hand then a lower protein target, knowing what research has told us about bone health and muscle maintenance in old age. But even many of my younger coaching clients have found improved satiety, better body composition, and improved athletic performance when they increase their protein intake.
Who Has Less To Worry About?
- Athletes who burn through tons of extra calories (Enough extra protein comes in, regardless of protein density)
- Those who eat at two-three servings of legumes per day (They’ll be close enough to the protein target for it to not matter, even if they’re eating an otherwise lower-protein diet.
Who Should Definitely Pay More Attention To Their Protein Intake?
- Raw foodist who are not very active athletes, particularly those who get most of their calories from lower-protein fruit like dates and bananas, and who don’t eat lots of leafy green vegetables. Even somewhat active raw foodists may have problems.
- Sedentary vegans who aren’t consuming much in the way of higher-protein-density foods.
- Anyone over 60
- Anyone having trouble gaining muscle and strength, despite vigorous strength training
What This Doesn’t Mean:
This doesn’t mean that vegans and raw foodists are “protein deficient,” in the ridiculous over-the-top way many people mean it. Western vegans don’t get kwashiorkor. It also doesn’t mean that you can’t be a good athlete or have a fair amount of muscle mass while eating a low protein diet – I did it for years and thrived athletically.
But the data we have indicates that suboptimal protein intake can take a toll, usually in the forms of impaired bone density and muscle accrual, response to oxidative stress, sarcopenia in old age, and probably in other areas of physical performance and health.
The vegan nitrogen balance studies mentioned above make it clear that adequate protein is a variable target, and two people can be at different nitrogen balances with the same protein intake. But as I mention below, “adaptation,” to a low protein diet might not be a good thing.
Addressing The Criticism:
People will balk at the idea that we need more protein than the RDA, because beloved vegan public figure X says they don’t, or someone’s diet – which they feel very healthy on – doesn’t exceed the RDA, or because they question the research I’ve presented here.
I can do nothing about anecdotes or somebody’s vegan idol, but I think it’s worth addressing some of the likely objections to the science I’ve presented here.
But Isn’t More Protein Bad For Us?
Animal protein is associated with more risk of death from all causes, and in particular, from heart disease. But more plant protein, on the other hand, is actually associated with lower risk of all-cause death and heart disease 18.
When it comes to cancer, merely getting men with prostate cancer to cut their ratio of animal to vegetable protein in half – from two to one animal to plant, to one to one – cut their prostate-specific antigen doubling time (used to estimate how quick prostate tumors are doubling in size) from 21 months to 58 months19.
The largest study examining the connection between diet and bladder cancer found that increasing the consumption of animal protein by 3% was associated with a 15% higher risk of bladder cancer, but a 2% increase in plant protein intake was associated with a 23% lower risk20.
There is also no evidence that higher protein diets put stress on the kidneys21
But Aren’t Vegan And Raw Food Diets More Protein-Efficient Than Omnivorous Diets?
Whole foods vegan diets, and raw vegan diets, can seem kind of magical. Plant-based diets – of the vegan and nonvegan variety – have a well-documented track record of reversing and preventing many of the diseases of affluence which afflict huge numbers of people. Research has even shown them to be remarkably effective against autoimmune conditions and digestive disorders.
I used a raw vegan diet to get rid of my colitis symptoms, something my doctor told me I’d never do – so it seems pretty magical to me. But when it comes to protein needs, we really have no reason to suspect that vegans, or raw vegans, need less.
If anything, there’s reason to suspect those on plant-based diets may need slightly more protein than someone consuming animal protein. Studies have found plant-based protein to be somewhere between 2.6% 22 and 10% 23 less efficiently digested than animal protein.
However, I wouldn’t consider this research solid enough to alter dietary targets.
But If A Low-Protein Diet Is Good Enough For A Breast-Fed Infant…
We grow faster during our first year of life than during any other period of existence. We do this on mother’s milk, which is only 6% protein. This fact is often used to justify a low-protein raw food or vegan diet. Since adult humans grow slower than babies, the reasoning goes, why shouldn’t 6% protein be enough for us too?
At first glance this idea makes sense (I bought it for years). But the logic breaks down if you do a little math. Check out my article on this subject for details.
The Problem With Nitrogen Balance Studies Is…
People have had problems with nitrogen balance studies and their relation to low-protein diets going back at least as far as the famous Kempner Rice Diet of the 1950s, which allowed people to eat unlimited quantities of low-protein fruit and rice, and almost nothing else. The program resulted in massive weight loss and the correction of numerous health problems, but several studies found the diet did not result in nitrogen balance.
This lead researchers looking at the effects of the rice diet24 to write:
“The phenomena that follow a sudden change of the dietary intake may be divided into the transient and the steady state effects. Whether the condition of the system at some later period of observation is dominated by one or the other of these depends on the length of time required for decay of the transients. Weight loss and negative nitrogen balances, which are transient effects, persisted in the larger subjects for at least three to five months after change of diet. Adaptation of sodium and chloride metabolism appears to be more rapid.”
In other words, they suspect that the negative nitrogen balance issues seen on this low-protein vegan diet would go away after three to five months.
However, the better question is – should we seek this adaptation if it means our bodily function is reduced?
Isotope tracer studies25 have found four stages of adaptation to low-protein diets: deficiency, accommodation, adaptation, and excess. Some nitrogen balance studies document people in nitrogen balance at low intakes of dietary protein because their body has adapted to this lower amount by downregulating physiologically important pathways, like muscle synthesis and perhaps immune function.
The researchers concluded their paper by noting that humans do not adapt to a low protein diet so much as accommodate it with reduced function. They write that the current RDA targets, “would probably diminish the individual’s capacity to withstand successfully a major stressful stimulus.”
But Being Muscular Isn’t Healthy
It’s easier to gain muscle when you’re eating a higher protein diet. I put on close to 15 pounds of lean mass in the 12 months since I started eating 1.2 g/kg of protein, despite not changing my training routine. Yet critics may object that more muscle mass is not healthier, even when it’s not accompanied by more fat mass. I would agree with this contention. Beyond a certain point, more mass, be it fat mass or muscle mass, it not healthier. Beyond a BMI of 17.5 – 22, you’re at an increased your risk of several diseases and all-cause mortality. The increased risk is small, but it is present. Keep in mind, however, that this is based on observational research, and we should be hesitant to read too much into it.
And not all decisions are based on health. I have a passion for partner acrobatics, and getting better at it has made me larger and stronger, pushing my BMI higher. I’m willing to make this trade off.
It’s possible to eat a higher protein diet and not gain muscle mass (you need to add significant resistance training and some excess calories to gain muscle). You also need to consider the effects of higher protein intake on satiety and weight maintenance, which I’ll be covering in future articles.
Vegan Protein Needs: Following Up
Through my review of the available research, my work with coaching clients, and my own personal experimentation, I’ve concluded that 1.2 g/kg is a protein target that brings about considerable benefits. Although adding more protein to a lower-protein diet requires different food choices and a greater degree of planning, I’ve found these hassles to be more than worthwhile. A number of my coaching clients and friends who were previously on lower-protein vegan diets have found the 1.2 g/kg target to bring some benefits after I recommended it to them.
If you’re curious, I’d suggest a three-month experiment to see how a higher protein intake affects you.
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