Originally published 17 April 2020. Last updated 26 August 2020.
Earlier this week on Episode 977, I read a post from Dave Smith of RomanFitnessSystems.com.
His post talked about his experiences switching to a vegetarian-type diet and the concerns that many people have about plant-based proteins.
I won’t repeat exactly what I said there, but instead expand on it and go into more detail.
Where Should I Get Protein From?
The first important thing to remember is protein is found in many foods. Foods just tend to differ in their quantity, types, and absorbability of proteins. So when someone refers to a food that contains “high-quality” protein, usually they’re referring to something that has lots of absorbable protein and contains all 9 essential amino acids. Remember that the term “essential amino acids” is just a fancy way of saying that these are proteins the body cannot make its own.
Instead, it’s essential we get these proteins in our diet.
What Foods Contain the 9 Essential Amino Acids?
Animal products are good examples of foods that contain all 9 essential amino acids and in a form that’s easily absorbed by the body. Eggs, yogurt, cheese, milk, meat, poultry, and fish would all be considered high-quality proteins because they are easily absorbed by the body and contain all 9 essential amino acids. This is why many that are trying to build or preserve their muscle turn to consuming animal products.
On the other hand, plant-based foods often do not contain all 9 essential amino acids. Whole grain bread and rice, for example, contain protein but they’re missing some of the essential amino acids. Quinoa and soy exceptions, though. Both actually do contain all 9 essential amino acids which is why you often hear them mentioned in post-workout meals and snacks.
Is Animal Protein Bad for You?
When we look at data from scientific studies, we see that for some, consuming lots of animal-based proteins may increase risk for certain diseases.
For example, some studies have found that consuming more than 18 ounces of red meat each week may increase a person’s risk for developing certain types of cancer.
Interestingly, red meat consumption may be more harmful to some that have ancestors that came from Southeast Asia. Whereas, someone whose ancestry traces back to northern Europe may not have the same reaction and therefore, the same risk for disease. This needs to be studied further, but it’s good to keep in mind nonetheless.
I should mention that the way these foods are prepared may also make a difference. For example, when a steak is cooked at high temperatures — like on a grill — it may increase the amount of harmful byproducts in the meat. Consuming meat with these byproducts, like polycyclic aromatic hydrocarbons, may increase disease risk.
We’re learning that foods that are naturally high in creatine, like red meat, tend to create more of these harmful compounds than foods like tofu. Plants contain no creatine, so if you grill your vegetables or tofu, you don’t get the same exposure to these potentially harmful compounds.
If you like grilling meat and poultry, you can reduce the amount of byproducts produced during the cooking process by first marinating it in an oil and citrus mixture, like olive oil and lemon juice.
What are the Benefits of a Plant-Based Diet?
We’re also learning that plant-based proteins don’t seem to increase disease risk in most people. They may even prevent some diseases.
I should mention that this reduction in disease risk may not be due to their protein content per se. Instead, plant-based foods also happen to contain vitamins, minerals, and dietary fiber. Many of the vitamins and minerals act as antioxidants. The fiber helps keep our gut microbiome healthy, which in turn, keeps our immune system happy and healthy, too. So a lot of the benefits of consuming plant-based foods go beyond the protein content.
But the bottom line when it comes to building or preserving muscle is that you can achieve this goal by following a well-planned plant-based diet. The key words being, “well-planned.” I’ve mentioned this before… I’ve known individuals that go all plant-based, but don’t eat any fruits or vegetables. Instead, they resort to eating white breads and pastas, marinara sauce, and cheese.
You could eat pizza and spaghetti everyday and be eating plant-based, but that doesn’t mean you’re eating a well-balanced diet.
If you’re concerned about getting enough of the 9 essential amino acids each day, be sure you consume a variety of foods, particularly beans and other legumes, nuts, seeds, and soy. Along with those foods, be sure that you’re consuming leafy green veggies, red and orange fruits and vegetables, toss in some quinoa and whole grain carbohydrates every now and then, and you should be fine.
How Much Plant Based Protein Do I Need?
This week, we heard from a listener about just how much plant protein one should be eating. Here's what she asked.
QUESTION: “Hello Dr. Neal, I have a question about plant proteins. I understand that many vegetables, fruits, nuts, etc. do not have complete proteins and therefore need to be combined to make a complete protein. My questions is on the combining. How do you know how much of each protein to take? Like, does one gram of x protein equate to 1 gram of y protein to make the complete x + y protein? And how long do you have to make that complete protein? If I eat the x protein in the morning and eat the y protein at dinner, will they still combine to make that complete protein? I hope this makes sense and thank you for your time.”
DR. NEAL: Your question makes perfect sense. It sounds like you’re wondering about whether the quality of plant-based proteins affects your overall protein status. Plant-based proteins are known for being of “poorer quality” than animal-based proteins.
This is something that you’ll hear fitness enthusiasts talk about all the time.
And, this is true to a certain extent. I’ll explain.
The Muscle Puzzle
Bear with me here: imagine you’re putting together a puzzle – one of those large, thousand-piece tabletop puzzles with a picture of a beautiful lush landscape in the foreground and a gray, medieval castle in the background. You’re getting to close to finishing this masterpiece and that dreaded moment comes around where a third of the puzzle isn’t finished, and you realize you only have 10 puzzle pieces left sitting in the box. Uh, oh!
Well, imagine all those puzzle pieces, the ones that are connected and the ones remaining the box, are amino acids. And the unfinished puzzle is, say, your biceps muscles. The body won’t be able to complete that beautiful puzzle, or maintain or repair your biceps, unless we find more of those missing pieces. Or, put another way, until we find those missing amino acids.
Plant-based proteins are like this giant tabletop puzzle with missing pieces. So, to move away from this analogy and use a reality-based example: eating a slice of bread or a bowl of rice alone for example, will not give you all the amino acids your body needs to build and maintain muscle. They are missing some of these amino acids – they are missing some pieces of the muscle puzzle. Hey, I like that! That’s kinda clever.
Combining Plant-Based Proteins
Now, while this sounds like terrible news, it actually isn’t a dire situation. I will repeat something that was published in a medical journal that sums up why plant-based proteins aren’t a problem:
“There is no need to consciously combine different plant proteins at each meal as long as a variety of foods are eaten from day to day because the human body maintains a pool of amino acids which can be used to complement dietary protein.”
(Source: MJA: Protein and vegetarian diets)
So, it turns out that as long was we consume a diet that includes different sources of plant-based proteins, the body will figure out how to combine them and use them to support the health and growth of, say, your biceps.
You may have heard someone blurt out, “If you’re going to eat rice, you better be sure you’re eating beans along with it otherwise you’re not going to get enough protein!” Tell them to mind their own business because that’s incorrect.
Going back to my puzzle analogy – remember I said each puzzle piece is like an amino acid? And, remember, they come together to form that beautiful landscape? Well, the body knows how to put together amino acids, just like you figured out how to put together a puzzle. If there are enough pieces in the box, your body will finish the puzzle on its own. And so long as you’re eating a variety of plant-based foods, you will have plenty of puzzle pieces.
I will also repeat something here that I’ve mentioned many times on the show before: the real key is creating the demand for muscle growth. If you want healthy muscles, you have to work them. You have to tell the body to send those amino acids to the muscle, instead of to the kidney for excretion or to storage as fat. The way to do that is to make the muscles crave those amino acids, so they get first dibs anytime you eat protein, plant-based or not.
Is Eating More Plant-Based Protein Necessary?
I haven’t forgotten that our listener was also wondering whether she needed to eat more total protein to make up for the fact that plant-based proteins don’t contain all the necessary amino acids.
Plant-based proteins aren’t as easily digested and absorbed. This is because plants have a natural barrier – they’re coated in fibrous material – which prevents the body from being able to access their amino acids. By the way, it’s this same fibrous material that provides us with dietary fiber – the very same dietary fiber that keeps the gut microbiome healthy.
A joint taskforce between the World Health Organization and the Food and Agriculture Organization suggested that vegans, specifically, may need to increase their daily protein intake. Again, this is to make up for the fact that plant-based proteins aren’t as easily absorbed by the body. So, vegans, may need more of it each day.
But, for vegetarians, most studies have found that there’s no need to increase daily protein intakes above what’s recommended for those that eat animal products.
Oh, and in case you’re wondering which plant-based protein is most easily absorbed by the body, processed soy (like tofu) ranks highest.