Plant-Based Protein: Can It be as Effective?

The adoption of ‘Vegan’ or ‘plant-based’ diets have increased in popularity over recent years. Within fitness and professional sports, prominent athletes like U.K. boxing champion David Hayes, Germany’s strongest man Patrick Baboumian, and Tennis legend Venus Williams have each adopted some form of a plant-based diet. We could talk endlessly about the various health and performance debates surrounding plant-based nutrition, but if there is one constant always under scrutiny, it’s protein. 

Traditionally, athletes have looked towards animal-based protein sources to fuel their physical endeavors — and with good reason: whey protein, eggs, chicken, beef, etc.. have been considered the gold standard for protein quality for many years.

But what does it mean for a protein to be high quality? Why is animal protein consistently favored over plant-based sources when it comes to building muscle and gaining strength? Can a plant-based athlete make the same gains as one consuming animal proteins?

Quality, Digestibility, & Leucine

First, a little refresher on the fundamentals. If you read our article about muscle protein synthesis, you’ll know proteins are made up of amino acids. The classic analogy is that they are the building blocks of protein. 

There exist 20 of these amino acids. 9 of them are essential, meaning that our body cannot produce them on its own — we need to consume them through food or drink. 

The idea of protein quality is fundamentally underpinned by the amount and balance of these 9 essential amino acids (EAAs) within a given food source. High quality protein foods have an abundance of the EAAs, and typically in nicely balanced ratios (not huge amounts of one and low amounts of another). Where muscle protein synthesis (MPS) is concerned, the more of these amino acid building we can provide, the better we equip our bodies for the muscle building process. 

Protein quality is not the only factor to consider, however: the digestibility of a protein source is also important.

Foods with lower digestibility are those whereby a larger percentage of total protein is lost to the digestive process. If we took a standard scoop of good quality whey, for example, almost all of its bound protein will be available for the body to use following digestion. A serving of chicken breast, beef, beans, or rice, may have a comparatively lower digestibility — just because you ate 25 grams of protein doesn’t mean all of that is readily available for the body to use. 

For many years, both measures of quality (the amount and ratio of essential amino acids) and digestibility (how much protein left with once digestion has taken place) have been surmised by the protein digestibility corrected amino acid score or PDCAAS.

This is a scoring system rating protein sources based upon their amino acid profiles and digestibility. The maximum score a protein source can achieve is 1, after which there is considered no additional benefit. 

Looking at the chart below, we can see that animal protein’s come out on top.

Besides a protein’s EAA ratios and its digestibility, there’s still one more very important part to the equation. Studies have demonstrated the EAA Leucine is perhaps the most important amino acid for triggering MPS (refer to the protein article for more in-depth coverage).  According to the research, 2.5g to 3g of Leucine per serving is required to maximize the MPS response.

So, while the literature is pretty clear that 0.8g of protein per pound of body weight is enough to maximize muscle growth, there is clearly some nuance. If you need 160 grams of protein per day, the amount you get in each meal and from what food is important. 

Considering animal proteins always have a high score, the above isn’t usually an issue. It will work itself out without the person even having to think about it. For the plant-based athlete, it becomes more of a consideration. 

It is not reasonable to expect people to be looking up every protein source using the PDCAAS, or meticulously tracking how much Leucine they’re getting in each meal, but on the other hand, plant proteins are often distinctly weaker in all three categories. 

Can the Vegan Diet be as Effective?

Despite the seemingly bleak theoretical outlook for protein-dense vegan diets, the practical evidence tells a different story. 

Most of the issues above can simply be overcome by having a little more total protein in each meal. Where 20 grams of whey protein may outperform the same amount from beans, bumping the amount up to 35 grams of bean protein may make the differences insignificant. 

Moreover, a popular choice among vegan athletes are protein powder blends: these supplements combine two good quality plant sources like pea and rice together to create a mixture roughly comparable to that of whey in quality, digestibility, and leucine content. In fact, studies have shown that even pea protein alone performed equally to whey so far as MPS was concerned, and that was when the doses between the two were actually equal. 

There are plenty of amazing plant-based protein supplements, and the market is growing all the time. Take Ambrosia’s ‘Planta’: our best selling vegan protein. With a blend of pea, brown rice, and fermented sunflower protein, Planta provides a high leucine, high EAA serving comparable to whey.

It’s also certified to be free of heavy metals. This is a potential issue for all protein powders, but particularly plant protein supplements due to the harvesting process. When you’re picking a supplement, make sure to check it is certified to be free of contaminants. 

Protein powders ultimately offer a brilliant alternative to whey, and even for those not fully adopting a vegan diet, plant-based shakes are great for those people with lactose or dairy intolerances. Of course, the majority of your diet should be coming from whole foods, so let's have a look at how they stack up.

Mycoprotein is another vegan protein source that’s gained a lot of traction. Sold as a wide variety of faux meat products under the brand name Quorn, 2016 saw the launch of a fully vegan line in the US (the original products often contained egg or dairy). Recent research looked into long-term lean mass gains when subjects ate either animal protein or mycoprotein, and the results showed no significant differences between the two groups. 

Thankfully, some of the best vegan protein sources are those packed with nutrients, and even without protein powder, overcoming the shortcomings in amino acid profile and digestibility can be relatively easy: so long as you eat enough total protein in a given meal and/or combine sources together, you should be getting all the EEAs you need to fuel muscle growth. 

The idea of an incomplete protein is largely false. While many plant proteins may be low in certain amino acids, the amount certainly isn’t zero -- there are only a handful of truly incomplete proteins such as gelatin and corn. 

Below are some great plant-based protein ingredients, and each have a ton of versatility in the meals you can create. Remember: the more you combine sources together, the better you make up for any amino acid deficiencies. 

There are also many other options. Though reasonably caloric dense compared to the foods in the table above, nuts and seeds are packed with protein; they’re perfect as additional toppings to a meal for some extra EAAs! 

As we touched on earlier, 0.8g of protein per pound of bodyweight is considered more than enough to maximize lean mass gains, but if you want to be totally on the safe side as a vegan, you could go with the classic 1g per pound of bodyweight. 

The Final Verdict

When all is said and done, the verdict on plant-based muscle building is clear: so long as you take some time to plan and prepare, there’s no reason you cannot maximize your gains on a vegan diet. Sure, it’s a little harder and a little more involved, but if you’re interested in giving the diet a go for whatever reason, there’s never been a better time. 

Linden Garcia Pepworth is a Sports Nutritionist (BSc Sports Nutrition) and YMCA Accredited Instructor. He is currently working on a review comparing the anabolic differences between plant and animal proteins.