Plant-based diets are often associated with sustainability, ethics and health benefits. But what about plant-based protein and muscle growth? Can they match animal proteins, are they even better? An update.
WHY DO YOU NEED PROTEIN AT ALL?
Proteins are indispensable for muscle growth. When you ingest proteins, they are digested into smaller blocks called amino acids. Chains of these amino acids are absorbed from the gut into the bloodstream. Your body breaks these chains down into individual amino acids, which in turn serve as building blocks for the protein in your body cells. Compare it to a child who breaks down a LEGO building and builds something else with the same bricks.
In the case of muscle tissues, we speak of muscle protein synthesis, in short, the process of building proteins in muscle cells. Muscle protein synthesis does not necessarily mean that a muscle is growing. This only happens when muscle protein synthesis exceeds muscle breakdown (as a result of overload in training). In that case we also speak of a positive muscle protein balance.
HOW MUCH PROTEIN DO YOU NEED FOR MUSCLE GROWTH?
It has been convincingly scientifically established that you need approximately 1.6 grams of protein per kilogram of body weight daily to build up muscle . That’s twice as much protein as a non-bodybuilder needs.
In addition, it has been shown that it is best to spread your protein intake evenly throughout the day in ‘shots’ (meals) of 20-40 grams. This is probably the best way to stimulate muscle protein synthesis. In practice, this means that you eat four to five protein-rich meals a day, with three to four hours in between.
It is therefore clear that the amount of protein plays an important role in muscle building. But what about the quality of proteins? Are all types of protein equally effective for muscle building?
ANIMAL VS PLANT PROTEINS
Based on scientific literature, researcher Jorn Trommelen concludes that animal proteins are slightly better for muscle growth than plant proteins. It should be emphasized that in most studies animal and plant proteins come out as equivalent, with a smaller number of studies in favor of animal proteins. There are no known studies in which plant proteins are the winner. This, again, when it comes to muscle building. See also a scientific review by Trommelen and his colleagues.
THE DOWNSIDES OF PLANT PROTEINS
Why is it that plant proteins for muscle growth are somewhat unfavorable? Drumming names three points.
1. LOWER CONTENT OF ESSENTIAL AMINO ACIDS
There are 22 amino acids in total. 13 of these can form the body itself. You get the other 9 from your diet. We call these essential amino acids. Based on protein content, animal proteins have a higher content of essential amino acids than plant proteins.
2. DEFICIENT COMPOSITION OF ESSENTIAL AMINO ACIDS
But not only the total number of amino acids is important, the composition of those amino acids also matters: the amino acid profile. Compare it to building a house: if you have bricks and windows, but no doors, you cannot build a well-functioning house. The same goes for building muscle protein: you need enough of all the individual essential amino acids. If a protein source is low in one of the essential amino acids, you are missing an ingredient for muscle protein synthesis. Many plant proteins are low in one or more essential amino acids.
3. LOWER DIGESTIBILITY
Digestibility is how well the protein can be digested into amino acids. Those amino acids are then absorbed (taken up by the intestines) and eventually transported to tissues such as muscles. So a digestibility of 80% would mean that 20% of the protein is not digested and excreted in the stool. That protein has not had the opportunity to do anything useful in the body, such as build muscle.
Plant proteins usually have a lower digestibility than animal ones. This is because plant-based foods often contain so-called antinutrients, which are intended to protect a plant, but which do not contain any nutrients.
In short, from a muscle growth point of view, plant proteins have several characteristics that make them inferior to animal proteins.
SOLUTIONS IN PLANT PROTEINS
However, that does not mean that you cannot achieve optimal muscle growth with a plant-based diet. Try one or more of the following solutions to make up for plant protein deficiencies.
1. EAT MORE PROTEIN
The first solution is simply to eat more protein. For vegetarians and especially for vegans, you should eat more protein than the regular recommendation of 1.6 g per kg of body weight per day. As a vegetarian, aim for about 2 g/kg/d with your protein intake, and as a vegan, aim for 2.2 g/kg/d. In this way you compensate for the lower content of essential amino acids, the less good composition of those essential amino acids and for the lower digestibility.
(Even) more protein is easier said than done. The protein density is on average much lower in plant products than in animal products. Getting 20 grams of protein from a steak is easy, but try getting them out of potatoes. In addition, you will need a lot of extra calories. ‘Just’ eating more proteins is therefore not ideal as far as we are concerned.
2. TAKE PROTEIN SUPPLEMENTS
Plant-based protein supplements are an easy way to increase your protein intake without unwanted calories from carbohydrates, and without filling you up as much as whole foods.
Plant-based protein supplements also have a high digestibility, which also solves the third problem with plant proteins.
3. ADD MISSING AMINO ACIDS
Another solution is to fortify foods low in a specific amino acid. For example, there are many meat substitutes and many of those products are enriched with lysine and methionine, two amino acids that are often lacking in plant proteins.
4. STRATEGICALLY MIX PROTEIN SOURCES
A fourth solution is to strategically mix two or more protein sources. If a protein is high in lysine and low in methionine, it is the perfect partner for another protein that is high in methionine and low in lysine. For example: peas combined with brown rice.
Sounds logical, but it does mean that you have to be well aware of the nutritional values of products.
CONCLUSION
The quality of plant proteins with regard to muscle growth is slightly lower than that of animal proteins. If you only eat plant protein, it is therefore best to supplement your diet with plant protein supplements. These provide you with a lot of plant protein, including the essential amino acids and with a high digestibility, at not too many calories.
But you can also get a lot of plant proteins from regular food. Legumes in particular are a protein-rich and healthy food source. Another recommendation is pea protein, which does contain a complete amino acid profile.