“But how do you get your protein?”
This is probably the single most common question posed to vegetarians, followed closely by questions about iron and B12. And for years I touted the classic vegetarian byline, “I don’t worry about it, there’s protein in basically everything.”
And it is true. I mean, you can find a little bit of protein in a glass of orange juice if you really look for it.
But when I started working with nutrition clients I started singing a different tune. Not all of my clients are vegetarian; in fact, I’d say that only about half of them are. But no matter whether they were strictly vegan or full-fledged meat eaters, I found that pretty much everyone I was working with could benefit from being more conscious about their protein consumption.
(The two exceptions to this have been one client who was on a self-administered high-protein low-carb diet when I got to him, and another who was in training for a marathon and needed to be all about carbs! carbs! carbs!)
The interesting thing is that no matter why a client came to me in the first place, becoming conscious about protein consumption made a difference. They had more energy. They felt more in control around food. They snacked less. They made more intuitive choices.
Recently though, I had a client tell me that she still doesn’t really get protein. So let’s get into it and learn all about protein, from what it is and what it does, to how much we need, and good plant-based protein choices for vegetarians.
What is protein?
Let’s back up the truck and start by talking about amino acids.
Amino acids are the building blocks of life. Getting technical, they’re an organic compound containing both a carboxyl (-COOH) and an amino group (-NH2). Amino acids bond together to form long chains, and these are known as proteins.
In total, there are 20 amino acids. Nine of these are essential:
These nine, we’re not able to make ourselves, so it is essential that we get them in our diets.
Some are considered conditional:
These are considered conditionally essential because they are essential only in certain cases. Many of the conditionally essential amino acids are essential in children, but not adults, or are essential in times of illness, stress, or trauma.
And the rest are non-essential:
3) Aspartic acid
4) Glutamic acid
Non-essential means that our bodies either have a supply of them, or we’re able to synthesize them on our own. Note again that most adult bodies are able to synthesize conditional amino acids, so these tend to get lumped in with non-essential on many lists.
Amino acids form proteins by forming long chains. Picture a piece of string with beads on it – each bead represents an amino acid, and the full chain of beads is your protein.
All proteins are comprised of all 20 amino acids, but they are put together in different combinations and contain different amounts of amino acids. So if you were comparing proteins it would be like comparing strings of beads with different combinations of coloured beads.
Some may have more blue beads and some may have more yellow beads. Some may go blue blue blue yellow blue, and others may go blue yellow blue pink green.
Get the picture?
Complete vs incomplete protein
You may have heard that animal foods like meat, milk, and eggs are sources of complete protein whereas plant foods like beans, rice, and vegetables are incomplete protein.
Guess what you guys: this is a myth. Yup. Totally false. It’s one of those long-standing pervasive food myths that just won’t go away, but let’s try to understand it.
The theory was that most plant foods were either missing or were very low in at least one essential amino acid, but this simply isn’t true. All plants are comprised of all 20 amino acids, just like all animal foods.
Nutrition theory of yesteryear told us that vegetarians needed to eat complementary proteins at the same meal in order to get the protein we needed. So for example, rice is low in the amino acid lysine, while beans are low in the amino acid methionine. Make a plate of rice and beans, and poof! You’ve got a good amount of both amino acids.
But guess what? As long as you are eating enough food to meet your total protein needs each day, you WILL get enough of ALL 9 essential amino acids.
It may not be fun; for example, if you were to eat nothing but rice it would take more than 14 cups of brown rice each day to meet your needs for lysine. But it can be done.
So while you *could* meet your daily protein needs on nothing but grains, or nothing but lettuce, eating a balanced diet is an easier – and more delicious – way to accomplish that goal, even if your diet is comprised entirely of plants.
Note: Amino acid digestibility tends to be lower for plant foods than it is for animal foods, but the difference is not enough to worry about.
Amino acid pool
When we consume protein, it gets broken down into individual amino acids in the gastro-intestinal tract and stored in an amino acid ‘pool’.
Amino acids are later taken from the pool and put back together as new proteins. The entire amino acid pool gets exchanged three to four times per day.
As long as there’s a constant supply of amino acids entering the pool (some from the diet, some from protein biosynthesis), we’re in business; when your body makes a new protein, it uses amino acids both from your diet AND from your amino acid pool.
Why we need protein
Protein is involved in prrrretty much every single cell in our body.
From providing a source of energy, rebuilding tissue and muscle, hormone production, immune health, enzymes, digestive health, and providing cell structure to the growth of our hair, skin, and nails, protein is where it’s at.
Think about the structure of our bodies – it is protein that does the work of holding together our cells, organs, muscles, connective tissue and bones. But proteins are equally important for our metabolic system; all of the enzymes in our bodies that trigger important chemical reactions are proteins.
And, key regulatory hormones, such as insulin, are also proteins, as are many important molecules in our immune system and cell transport and messaging molecules. So you can see, protein is vitally important for our health!
How much protein we need
The formula for daily protein requirements that we’ve been working with up until now is 0.8 grams of protein per kilogram of body weight for the average person (this doesn’t include pregnant people or serious athletes).
This means that an adult weighing 150 pounds = 68kg x 0.8 would need to consume about 55 grams of protein each day.
However, recent research has suggested that our basic daily protein requirements may have been significantly underestimated.
This new research suggests that a more realistic estimate of our daily protein needs is actually somewhere between 0.93 and 1.2 grams of protein per kilogram of body weight. Using this formula, a 150 pound adult would need between 64 and 80 grams of protein per day.
A more simple way to average out this equation is to simply divide your weight in pounds in half, so an adult who weighs 150 pounds would therefore require 75grams of protein; easy math.
When it comes to pregnancy, newer research is suggesting that the protein requirements here, too, have been drastically underestimated. The problem is, the current recommendations for protein requirements in pregnant women are based on studies of non-pregnant people, including men, and then “adjusted” to estimate the protein needs during pregnancy.
However, A 2015 study – the first ever study to directly estimate protein needs in pregnant women – showed that actual protein needs were 39% higher in early pregnancy (before 20 weeks) and a whopping 73% higher in late pregnancy (after 31 weeks) when compared to the current daily recommendation of 0.8 grams per kilogram of body weight.
That means that in early pregnancy the protein requirement would be closer to 1.22 grams and in late pregnancy, more like 1.52 grams of protein per kilogram of body weight.
Where to get your protein
All right, we’ve made it this far, so now you may be wondering exactly how to include protein in your diet. Below I’ve provided the amount of protein that is provided by a serving of several foods that are included in typical vegetarian diets.
Note that I am including foods for both lacto-ovo and vegan diets. If you’re strictly plant-based, you can ignore the first five foods and go directly to the plants.
- 1 egg: 7 g
- 1/2 cup 1% cottage cheese: 14 g
- 1/2 cup plain yoghurt: 5 g
- 1 cup 1% milk: 8 g
- 30g cheddar cheese: 7 g
- 100g firm tofu: 12 g
- 100g tempeh: 18 g
- ½ cup shelled edamame: 13 g
- 1 cup cooked lentils: 18 g
- 1 cup canned black beans: 15 g
- 1 cup canned kidney beans: 13 g
- 1 cup canned chickpeas: 12 g
- 2 tablespoons peanut butter: 8 g
- 30g (about ¼ cup) dry roasted peanuts: 7 g
- 30g (about ¼ cup) almonds: 6 g
- 1 cup plain soymilk: 8 g
- 1 cup cooked quinoa: 8 g
- ½ cup rolled oats: 5 g
- 3 Tbsp hemp seeds: 10 g
- 2 Tbsp nutritional yeast: 8 g
- 1 cup broccoli florets: 3 g
- 1 cup steamed kale: 3 g
How to get 75 grams of protein each day
If the prospect of getting 75 grams of protein in your diet each day seems daunting, worry not! Remember that it all adds up, and that basically everything, even vegetables, will contribute to your daily protein intake.
The main thing is to focus on a balanced diet that includes a variety of plant foods including vegetables, whole grains, beans and legumes, nuts, and seeds. Remember that so long as your overall protein intake meets the minimum requirement, you’ll be sure to have an adequate intake of all essential amino acids.
Other nutrition posts to check out
First published September 15, 2015. Updated and republished on August 30, 2019.