Complete Protein Foods for Vegans & Vegetarians
A ‘complete protein’ contains all 9 of the essential amino acids necessary for the body to form a protein, whereas an ‘incomplete protein’ lacks one or more of the essential amino acids. ‘Amino Acids’ are the building blocks of protein. Non-essential amino acids can be produced by the body, while Essential amino acids must be supplied in the diet
We know that animal foods (such as meat, poultry, fish, dairy products and eggs) are ‘complete proteins’, but are there some plant based ‘complete protein foods’ that are suitable for vegans & vegetarians? Is it possible to get sufficient amounts of these amino acids on a plant based diet?
Let’s see what Laura Oliver, a Registered Dietitian has to say
In summary, plant foods often lack at least one amino acid (with the exception of some foods such as quinoa, buckwheat, hemp seeds, chia seeds & soybeans). So the best way to ensure you get enough of these essential proteins is by doing the following:
Method 1: Include a variety of plant foods to serve as a complete source of amino acids
Combining 2 of the following foods (that are not complete proteins) will make up a ‘complete protein’ meal and ensure that you get all the 9 essential amino acids your body needs:
1 Grain + 1 Legume
(eg. rice, pasta, corn, oats, wholewheat foods) + (eg. Beans or Lentils)
1 Nut + 1 Legume
(eg. almonds, walnuts, cashews etc.) + (beans, lentils or peanuts*) *considered a legume, not a nut
1 Seed + 1 Legume
(eg. sesame seeds in tahini) + (chickpeas) = hummus
Note: You do not need to consume these ‘complete protein meals’ in one sitting however, these can be obtained over the entire course of the day. Our bodies can combine these amino acids within 24 hours of eating them, so purposely combining them is not necessary. Vegetables also contain some protein which can bump up the protein profile as well.
Some meal examples:
1 cup Rice + Beans = 7 grams of protein
2 Tbsp Hummus (chickpea & tahini spread)+ 1 Wholewheat PitaBread = 7 grams of protein
2 Tbsp Peanut Butter + 2 Slices Wholewheat Bread = 15 grams of protein
Banana & peanut butter sandwich (with two slices of bread) has 18-22 grams of protein. Hows that for a protein packed meal!
Vegetable Stir fry with green soybeans + Brown Rice + Sesame Seeds
Method 2: Incorporate plant based ‘complete protein foods’ in to your meals
We have just learnt that, despite common belief, it is indeed a misconception that only meat or animal foods contain complete proteins. Consume these plant based ‘complete protein’ foods to get adequate amounts:
- Quinoa (1 cup = 8 grams)
- Buckwheat (1 cup = 6 grams)
- Hemp Seeds (2 tbsp = 10 grams)
- Chia Seeds (2 tbsp = 4 grams)
- Soybeans (eg. 1 cup tempeh = 31 grams)
Bottom Line: Our bodies can store amino acids to be utilized at a later time to build proteins from various amino acids obtained throughout the day. As long as a variety of vegetarian protein sources are consumed throughout the day (not necessarily in one meal), sufficient amounts of amino acids can be obtained by the body. Complementary proteins therefore do not need to be eaten together for your body to use them. Although it is not necessary, it may be beneficial to include some of the ‘plant based complete protein foods’ (mentioned above) to boost protein intake.
What about Digestibility?
Although it is true that plant proteins are slightly less digestible than animal proteins, by consuming a combination of plant foods increases the overall biological value of food.
The ‘biological value’ is a measure of the proportion of absorbed protein from a food which becomes incorporated into the proteins of the organism’s body. It captures how readily digested protein can be used in protein synthesis in the cells
~ Wikipedia Definition
Most plant foods contain all 9 essential amino acids, but it is the proportions of these that vary and which is why they may not be as well digested as animal proteins. However, even after accounting for these differences in protein quality or digestion, there are sufficient amounts of protein in most plant foods (except for fruit), and one can easily obtain all essential amino acids by eating a variety of plant based foods.
It is quite easy to get all the protein your body needs on a vegetarian or even a vegan diet (which is a bit more restrictive). As long as we are consuming a mixture of plant based protein sources including whole grains, beans, legumes, nuts and seeds, and meeting our calorie requirements for the day, there is no need to worry about sufficient protein intake. By eating a combination of these complete protein plant foods, it is pretty much impossible to be deficient in any of the essential amino acids (1). You can easily meet and even exceed daily protein requirements on a vegan or vegetarian diet.
For example, simply eating baked beans on toast can give you an adequate mix of all essential amino acids.
It should be noted however, that lacking overall plant based protein sources in the diet may lead to some minor protein deficiencies. This is why it is extremely important to include at least 1 vegetarian protein source at every meal and to include a wide range of plant-based protein foods in your diet.
Position of the American Dietetics Association (2009). Vegetarian Diets. Journal of the ADA, 109 (7), pg 1266-82