TL;DR: Extensive research, newly compiled, tells us how much protein we need for optimal aging, strength, and muscle mass: around 1.6 grams of protein per kilogram of body weight (.73 grams per pound). This goes even if you’re a vegan or plant-based eater. This need for more protein than provided by the RDA becomes increasingly important as you get older.
How Much Protein You Need
Exactly how much protein you need is an interesting area of nutritional contention. Almost uniquely in the nutritional world, many of those promoting plant-based or vegan diets suggest the RDA of 0.8 grams per kilogram (or around 0.36 grams per pound) of body weight is perfectly sufficient for everyone.
This was a tenable position when I started eating a vegan diet more than 13 years ago. But as I’ve pointed out previously, the last decade of research has called this target into question.
Research has pointed out that we likely need considerably more for optimal health, aging, and body composition. Frequently, proponents of lower protein targets will cite human breast milk as justification for a lower target, but you should be aware that this argument is flawed.
A new meta analysis further drives home the point that health is better with a protein intake higher than the RDA.
Why You Should Consider This Study
There are hundreds of protein studies out there, but most them are of questionable use when trying to draw broad conclusions. Most of them have at least one of these flaws: They take place over too short a period of time to draw conclusions, there are not enough participants being studied to achieve much statistical significance, and often, specific types of isolated protein supplements, (soy, whey, etc) are being tested rather than protein intake as a whole. Many of them only focus on a specific type of person, such as body builders, young men, elderly people, or other groups.
This new study1 is a meta-analysis that drew on 49 high-quality experiments following 1,863 men and women of all ages. Some were experienced strength athletes while others hadn’t done any strength training. Some followed the RDA for protein, while others in the intervention groups were instructed to eat more protein. All had their strength and muscle mass measured before and after the experiments. The types of protein (plant vs animal, whole food vs supplement) varied, and the time of day they consumed the protein also differed.
More Protein Makes A Difference
Yes, eating more protein than the RDA does make you stronger and increase your muscle mass when compared to just hitting the RDA. Those who consumed what the researchers found to be “optimal,” protein intake were roughly 9% stronger than those who did not, and gained about 27% more muscle mass over the course of the experiments.
There’s A Limit To Protein’s Usefulness
“Optimal,” protein intake for strength and muscle mass appears to be nowhere near what protein supplement manufacturers want us to think it is. Strength and mass stopped increasing over the RDA at 1.6 grams per kilogram of bodyweight, or .72 grams per pound.
That’s 127 grams for a 175-pound man, and 94 grams for a 130-pound woman.
Strength Training Matters More Than Protein
At the end of the day, you’ll get a way larger increase in strength and muscle mass from strength training than you will from upping your protein intake.
By comparing strength and muscle mass increases in those consuming extra protein and those who did not, the researchers found that the lion’s share was caused by merely lifting heavy things.
This agrees with my own findings. I was able to increase strength and mass while eating a low protein raw vegan diet consisting of only 5-7% of calories from protein (around 50-60 grams per day), as I talked about in this video. You’ve also got guys like Mike Vlasaty who can pull 500 lbs off the ground while weighing 145 pounds and eating a low protein vegan diet.
Since I was eating less than the RDA during my years eating a strict raw vegan diet, I believe my own strength and mass gains have been considerably higher after increasing my protein intake, but It’s clear that you can increase strength and mass even on a low protein diet if you’re willing to put in the work.
Experienced Athletes Need Protein More
The muscle mass gains of experienced strength athletes were augmented far more by the addition of protein than those who had never done strength training.
Protein Intake Matters More The Older You Get
After age 40, your ability to maintain and build muscle mass decreases. Sarcopenia, or the progressive decline of skeletal muscle as you get older, limits your physical function, while causeing frailty, falls, and other issues. By age 80, many people have only 50% of the muscle that they had when they were 30.
This study pointed out that strength training can counteract that loss, but its ability to do so decreased as participants got older. The additional muscle-stimulating effects of protein became more pronounced as the participants got beyond age 40.
Your Protein Source Doesn’t Seem To Matter
The participants in the study took in protein from a variety of whole-food and supplemental sources, but the researchers found there was no difference in outcomes, regardless of whether or not people got their protein from fruits and leafy greens or beef and whey protein.
Only total intake seems to matter.
Not Applicable To All Circumstances
The findings of this study don’t necessarily apply to people in all circumstances. For instance, as I point out in this article, if you’re trying to lose weight and want to preserve your muscle mass while you do it, upping your protein intake and engaging in strength training while running a calorie deficit is probably a good idea.
I’ve benefited quite a bit from upping my protein intake over the last few years, a change I made after looking at the increasing scientific consensus on its merits. I feel stronger and more resilient as a result, and I believe research has made lower protein diets questionable in a number of ways.
I suggest my coaching clients at least spend a few months eating a minimum of 1.2 grams per kilogram of bodyweight as an experiment.