The Myth of Protein Combining and the Truth About Complementary Protein

We often hear conflicting information about what the best protein sources are, but do you really understand this essential nutrient?  

Proteins are made from long chains of amino acids. This nutrient is one of the primary building blocks of the body’s tissues and it is critically important for overall health and fitness. It is common knowledge that the human body needs protein to be healthy and strong. However, not all proteins are created equal, which led to an unhealthy 1970s fad diet that made people believe it was necessary for the body to eat protein from both plant and animal sources in order to be healthy. This has been found to simply not be the case.  

This erroneous theory was based on the difference between complete and incomplete protein sources. A complete protein contains all nine of the essential amino acids that must be obtained from the diet in order to prevent malnutrition. Since plant-based protein sources do not contain all nine essential amino acids, they are therefore classified as an incomplete protein.

The concept of protein combining stemmed from a belief that a vegan and/or vegetarian diet would not provide a sufficient source of amino acids and that it would be necessary to supplement plant-based protein with animal-based protein to achieve a complete amino acid profile. While it is true that some common plant-based proteins are not complete proteins, it is still possible and even common to obtain all nine essential amino acids from only plant-based sources. 

The American Dietetic Association has published research concluding that a vegan and/or vegetarian diet is capable of providing all the necessary amino acids. There are several plant-based sources that offer complete protein, including quinoa, tofu, tempeh, edamame, amaranth, buckwheat, hemp seeds, chia seeds, and nutritional yeast.   

Additionally, in a vegan or vegetarian diet, all nine essential amino acids can be obtained through a practice called protein complementing. Protein complementing is simply eating protein from different plant-based sources in order to consume all nine amino acids. Consuming protein from a variety of sources plant-based fulfills the requirements for making a complete protein and yet avoids the harmful impact of consuming animal-based products. 

Complementary plant-based proteins can include the following delicious options: 

  1. Hummus with whole-wheat pita bread 
  2. A nut butter sandwich on whole-grain bread 
  3. Beans and brown rice 
  4. A tasty salad with beans and nuts or seeds 
  5. Tofu with quinoa

Following a plant-based diet and ensuring the proper intake of amino acids is not only possible but can even be easy when a variety of foods are eaten each day.