Protein on a plant-based lifestyle

The question of "where do you get your protein?" is posed to many vegans or vegetarians all around the world. While plant-based foods are certainly becoming more popular, protein is still often equated with animal products such as meat, fish, eggs, and dairy.

Not only is it possible to get enough protein on a plant-based diet, but it's also relatively easy to do so without having to eat tofu all day long. The amount we need may not be as difficult to have as some may think!

Functions of protein

Protein is one of the 3 macronutrients, alongside carbohydrates and fats. It's extremely important in the overall structure, function and metabolism of our body. Here are just a few of its functions:

  • Structure: collagen, keratin, and elastin are all proteins that play a structural role in muscles and other tissues.
  • Hormones: proteins can act as chemical messengers to transmit signals, such as insulin. 
  • Transportation: proteins help with transportation throughout the body. For example, hemoglobin is a protein that carries oxygen from the lungs to body tissues.
  • Immune defence: antibodies & immunoglobulins are proteins that protect the immune system.
  • Enzymes: proteins partake in several metabolic processes in the body.

Each type of protein consists of a specific sequence of amino acids. These amino acids are the small "building blocks" of larger protein structures. There are 20 different amino acids that can be combined to make a protein. The human body requires all 20 identified amino acids for proper growth and development on a day-to-day basis. 11 of these amino acids are called "non-essential" amino acids, meaning that our bodies are able to produce these on their own. This means seeking food sources rich in these amino acids isn't necessary. There are 9 amino acids, though, which are labelled "essential". This means that our bodies cannot produce them, so we need to consume them from foods.

Protein requirements

How much protein we need can vary based on our age, build, activity level, health status, presence of any illnesses, and so on. It's true that plant-based proteins may not be as efficiently absorbed in the body, but the difference is quite small. By eating within the range below, we can adequately meet our needs.

The protein requirements for an average adult is 0.8g/kg - 1.0g/kg of body weight. So, if someone weighs 143lbs (143 lbs / 2.2 kg = 65 kg), then their general protein requirements would be 52-65g per day (0.8 g x 65 kg and 1.0 g x 65 kg). 

Keep in mind that requirements will be higher for young children, elderly people and for pregnant women. It's encouraged these groups to speak with a dietitian regarding their specific protein requirements.

sweet and sour tofu with rice
Our sweet and sour tofu stir fry features tofu as a source of protein.

Food sources

There are loads of plant-based food sources, below is a list of just a few top ones.

11-20 g of protein per serving

  • Tempeh, cooked (½ cup)
  • Edamame (½ cup)
  • Tofu (½ cup)
  • Peanuts (¼ cup)
  • Hemp seeds (¼ cup)

5-10 g of protein per serving

  • Lentils, cooked (½ cup)
  • Buckwheat, cooked (½ cup)
  • Chia seeds (¼ cup)
  • Green peas (1 cup)
  • Artichoke (1 cup)
  • Spinach (1 cup)
  • Rolled oats (½ cup)
  • Quinoa, cooked (½ cup)
  • Beans (most varieties), cooked (½ cup)
  • Nutritional yeast (2 tbsp)
  • Almond butter (2 tbsp)
  • Tahini (2 tbsp)
  • Soy milk (1 cup) 
Pro tip: soy milk is often recommended because it provides protein similar to cow's milk, whereas other plant-based kinds of milk don't offer this much protein. We can opt to use soy milk more often to boost our protein intake!

Complimentary proteins

As mentioned above, there are 9 essential amino acids that we need to get from foods. If a food item contains all 9 amino acids, it's called a "complete protein". Examples of complete protein include buckwheat, quinoa and soy.

However, some plant-based protein sources are low in a few specific essential amino acids, namely lysine and methionine.

For example, most Grains tend to be high in methionine but low in lysine, while most legumes tend to be high in lysine but low in methionine. This is where the idea of protein combining emerged. It was thought that if a person combined these "complementary" proteins in the same meal, they would optimize the availability of the protein so one food group would "make up" for the lack of particular amino acids in the other food group. We now know that we don't necessarily need to consume these two foods in the same meal. Simply having them within the same day will have the same effect. By consistently consuming a varied diet from all food groups, we'll likely have our bases covered.

We may find that many commonly eaten foods are already complementary, for example:

  • Toast with nut butter
  • Hummus with pita bread or whole-grain crackers
  • Rice and beans, in a nourish bowl, wrap, or taco
  • Stir fry with tofu or edamame served over rice or with noodles

To learn about creating a nutritionally balanced plate, see our plate method article.

2 bowls roasted edamame chips
For a protein-packed snack, try our roasted edamame chips.

Protein and exercise

It's a common misconception that all athletes require high protein intake. It's true that athletes who train at an elite level have higher requirements at about 1.2g-2.0g/kg of body weight to account for the building of extra muscle tissues. For an average adult that regularly exercises, though, 0.8g-1.0g protein per kg of body weight is enough to meet their needs.

Supplementation & protein powders

Here at PUL, we're a big fan of obtaining nutrients from food first, when possible. The same goes for protein. It's absolutely possible to obtain adequate levels from food alone, even as an athlete.

With that said, if our requirements have been determined to be very high or we're otherwise unable to meet our needs from food alone, we may choose to supplement with a powder. Some plant-based sources include soy protein, pea protein, hemp protein, flax protein, chia protein, brown rice protein, and more. When looking to purchase protein powders, we can try to aim for brands that aren't heavily sweetened.

Summary

  1. It's doable to have adequate levels of protein on a varied plant-based diet. Supplementation isn't necessary, as having a variety of different plant-proteins is enough. 
  2. 0.8g - 1.0g of protein per kg body weight is how much the average adult who exercises regularly needs to meet their needs. Requirements will be different for children, the elderly, pregnant women and high endurance athletes.
  3. The best plant-based sources include legumes and grain products such as tempeh, lentils, beans, quinoa, buckwheat. Other great sources include nuts, seeds and some vegetables.
  4. Elite endurance and strength athletes require higher levels of about 1.2 - 2.0g/kg of body weight. Protein requirements for an average adult who exercises regularly remain at 0.8g - 1.0g/kg of body weight.
  5. Focus on obtaining protein from food first, before turning to supplements. Aim to choose whole plant foods over processed vegan substitutes if possible, as these may contain higher levels of sodium and saturated fat.