How To Get Enough Protein On a Plant-Based Diet
“Are you a vegan?”
“No, but I eat 95% plant-based diet.”
“Ok, whatever. But where do you get your protein then?”
If I would get a dollar…
In all fairness, when your goal is to put on lean muscle, or to maintain a higher than an average punter’s lean muscle mass, the science is clear that the body requires a fair bit of protein. And for the plant-based eaters who rather eat real food instead of relying on vegan, fake “meats”, it can be tricky to manage it all without a clear understanding of how to do it.
Although it can take some planning in the beginning, the good news is that there is more than plenty of protein in plants to fuel your muscle gains. To expand on it, let’s dig our forks into the vortex of the every man’s favourite biological molecule.
Protein is uber-important for building muscle
Proteins live and play house in all the cells of the body. The proteins in your muscles, along with eating a caloric surplus and following a progressive resistance training program, are the cornerstones to building lean mass.
Proteins are made of 20 amino acids, 9 of which the body can’t make on its own: phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine. If the body can’t make these 9 amino acids where to we get them then? Food. Why is this important?
If we don’t get enough protein from our diet, which means not enough of those 9 amino acids, the limited proteins won’t give two shits about your muscles. Instead, they will leave the muscle to go play a hero in other processes the body needs to keep you alive. Like, oh I don't know, making sure that your organs are still having a decent time and not dying.
Further, protein exiling a muscle is super sad because when your goal is to have an athletic body the last thing you need is limited resources of proteins who go play Batman and save organs. I am all for having well functioning organs, but it sucks to put in all the work in the gym and see your bicep shrink in front of your eyes.*
Don't look at the dietary guidelines for average punters
Since you’re a non-sedentary individual with the goal of an athletic body, you need more protein than what some recommended dietary guidelines say. Let's remember that you are after optimal protein levels to support your training and athletic endeavours, not just to have enough food to survive a cold winter.
We can ignore the U.S. Recommended Dietary Allowance (RDA) of 0.8g/kg as it‘s been proven to result in loss of lean mass, even when the participants were eating 40% more calories than they needed to maintain their weight. In contrast, the higher protein intakes were associated with increases in lean mass. 
The most comprehensive meta-analysis** of protein on muscle mass and strength concluded that the minimum amount of protein to maximise lean mass is somewhere around 1.6g/kg.  And when narrowed down to studies involving amateur bodybuilders instead of novices, the optimal protein requirements for these folks was 1.7-2.2g/kg on their non-training days.
High protein diets and health
According to hard science there are no negative side effects in healthy people eating higher protein diet. Yet one has to wonder. Since higher protein diet means better muscle growth does this also mean higher growth rate of all the other cells in the body? Including cancer cells?
On the flip side we know that lean muscle mass is important to longevity. At least to longevity where the person can still be a fully functioning member of the society. If being a fully functioning member of the society seems like a great deal to you, we wouldn't advice going ultra low on protein either.
As is often the case the answer lies somewhere in the middle. Go too hard at protein and muscle gain and you will probably negatively affect your longevity. Just look at all the big power athletes, they don't tend to live too deep into their 70's. In contrast if you completely ignore protein you will probably again negatively affect your longevity due to ending being a living skeleton that breaks in the wind.
Based on that we would recommend starting at 1.6g/kg and adjusting depending on results. For the sake of minimum effective dose why do more if you can get it done with less. Might save your money and your health.
Are plant based proteins less anabolic or less complete compared to animal proteins
There are plenty of fear-mongering articles online about plant based proteins not being “complete” because none of them contain all the 9 essential amino acids. But studies show that as long as you are eating a decent amount of protein (1.6g/kg, anyone?) from a variety of sources each day you don‘t need to obsess over the “incompleteness” of plant based proteins.
For example, although leucine is important for maximising muscle protein synthesis (you want this to build muscle) you’ll have enough by focusing on the total amount of protein from a variety of sources. Sounds like fun compared to obsessing over the amounts of individual branch chain amino acids. Yawn.
As long as you include beans and legumes (lysine), soy beans and lentils (leucine), tree nuts and chickpeas (leucine, isoleucine, valine) in your diet you’ll cover all the bases and achieve a full amino acid profile in your diet. That on it‘s own will save you the hassle and unnecessary amino acid related math stress.
Side note: body absorbs supplements better compared to wholefood sources
Most studies done comparing animal and plant based proteins are done on supplements. As an example, wheat protein isolate has a digestibility of 90% compared to 45% of whole protein.  What this means is that when relying on mostly wholefood sources that are not as digestible you could justify pumping your protein up to 2.0g/kg instead of the 1.6g/kg.
Still, as explained earlier, we’d go by 1.6g/kg and adjust based on your results, and the size of your bicep.
Does eating soy make you limp and give you with man-boobs?
Again, scan the internet and you’ll find countless articles fear-mongering and demonising various soy products and supplements. But these arguments are often cherry picked studies for the sake of creating clickbaitable headlines. The truth, as always, is not so black and white.
Again, let‘s lay down the groundwork for us to stand on: soy isoflavones are bioflavonoids found in soy. These little fuckers can interact with various hormones, such as estrogen. In theory, isoflavones can negatively affect the activity of enzymes involved in testosterone production. And in theory this would mean that testosterone goes down and high fives estrogen who is climbing up.
Yet, the current science doesn’t correlate with this as there hasn’t been a significant difference in total free testosterone or estrogen to testosterone ratios in any studies comparing young, resistance training men who used protein supplements containing various amounts isoflavone (whey protein concentrate, soy protein isolate, soy protein concentrate, whey-soy protein blend)  And as a bonus, soy doesn’t appear to impact fertility either. 
Now, there have been two case reports that show adverse effects of excessive soy isoflavone consumption over a period of 6-12 months. In one case a 60-year-old male drank 2.8 litres of soy milk a day leading to man-boobs, erectile dysfunction and reduced sex drive. In the other case a 19-year-old vegan type 1 diabetic ate large quantities of soy products and had to put up with (sorry, couldn’t help myself) erectile dysfunction and hypogonadism, a condition where the body doesn’t produce enough testosterone.
The takeaway? Anything in excess is not good for you. Be it peanut butter, chickpeas, my wife's rhubarb crumble, or soy products. To finish on a high note on soy, let’s not forget that soy may reduce the risk of developing prostate cancer.
The best plant based protein sources
This is just the tip of the plant based protein iceberg. There’s also protein in brown rice, broccoli... Spinach in particular is super high in protein but you’d need to eat a metric-shitton of it. Either way, name a plant and there‘s protein in it. And as you can see later on in this article even if the quantities are not as high in the foods that are not on the list below, the little amounts from various sources still significantly add to your daily totals.
Case study: How can Paulie get enough protein
Paulie is a decent bloke, currently weighing 75kg with 12% body fat and after some gains. First, based on what we’ve been through by this point let’s calculate the amount of protein a 75kg male should aim each day, as a starting point:
75kg x 1.6g of protein = 120g of protein per day.
Not an excessive amount by any means. By eating 3 meals and a post workout shake, here’s how it will look without any protein supplements.
Two thick slices of sourdough rye bread with two tablespoons of 100% peanut butter
A salad of baby spinach, capsicum, tomato, avocado
Chickpeas, mushroom and broccoli stir-fried with virgin olive oil and spices
100 grams of oats
two handfuls of baby kale
one large ripe banana
raw cacao powder
500ml coconut water
ice until the teeth clatter
Plant based bolognese with lentils, tomatoes, basil, salt, pepper
Dessert: mango with coconut milk, hemp seeds and cacao nibs
Total protein for the day climbs up to 122 grams. And in case you're wondering: the total carbohydrates climb higher than we’d probably need, but with that much fibre in the diet (fibre isn’t digested and therefore doesn’t count toward the daily calorie total) it shouldn’t be an issue.
Getting enough protein with a plant based diet is not that hard. The main issue we see most guys running into is the total volume of food. That’s a lot of chewing, even for Ridge Forester. If you want to make this a step easier for your jaw include a serve or two of plant based protein powder in the post workout super-shake and reduce the protein sources accordingly from other meals.
And when it comes to the burning concerns of negative effects of soy, or getting a full amino acid profile and whatnot: eat from a variety of protein sources instead excessively pounding down just one.
Then, stop obsessing over protein. You probably don't need as much as you've been told in the past. Focus on eating a wholefood diet with a decent serving of protein rich plant food at each meal. You'll be fine.
*not entirely true. It doesn’t happen that fast
**a fancy way of saying “we studied a bunch of other studies and came to the following conclusion…”
 Effect of dietary protein content on weight gain, energy expenditure, and body composition during overeating: a randomized controlled trial (2012)
 A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults (2018)
 Ingestion of Wheat Protein Increases In Vivo Muscle Protein Synthesis Rates in Healthy Older Men in a Randomized Trial (2016)
 Effect of protein source and resistance training on body composition and sex hormones (2007)
 Soy protein isolates of varying isoflavone content do not adversely affect semen quality in healthy young men (2010), Effect of a phytoestrogen food supplement on reproductive health in normal males (2001)