What are complementary proteins? If you consume a plant-based diet most of the time or are vegan or vegetarian, this is something you should know! Read on to find out more.
What is protein?
Protein is one of four macronutrients. It provides us with calories and is an important part of every cell in the human body. It is truly essential for growth and development. Having enough protein is especially important in maintaining a strong immune function, building muscle mass, and helping wounds heal.
The building blocks of protein are amino acids—think of them like car parts. There are 20 different amino acids, or car parts, that can be mixed and matched to make up many different types of proteins, or cars, that you see on the road. Of these 20, nine are essential as they cannot be made by our bodies. They are histadine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The rest are non-essential as they can be made by the nine essential amino acids, or through breaking down existing protein in the body.
Complete and incomplete protein sources
Complete protein sources: Contain all nine essential amino acids. They include animal products such as meat, chicken, seafood, dairy products, and eggs. Soy is the only plant-based protein that is a complete protein source and belongs in this category.
Incomplete protein sources: Do not contain all nine essential amino acids. They include plant products such as vegetables, grains, legumes, nuts, and seeds.
Complementary proteins for vegans and vegetarians
If a food you’re eating is a complete protein source such as soy-based products like tofu, beancurd, tempeh, or soy milk, there’s nothing to worry about!
However, if you’re consuming foods that are incomplete protein sources, pay close attention here. Incomplete protein sources have different limiting amino acids. For example, legumes (except soy) are low in methionine, while grains, nuts, and seeds are low in lysine. That means if you’re consuming only legumes, you may not be getting enough of the amino acid methionine. On the other hand, if you’re only consuming grains, nuts, or seeds, you may not have sufficient lysine.
This is where the idea of complementary proteins comes in. Vegetarians and vegans should consume legumes along with grains, nuts, or seeds to get all nine essential amino acids. This does not have to happen within the same meal, as long as they are consumed within the day.
Check out this hearty and easy-to-make Mexican Bean Soup recipe which has complementary proteins from grains and beans!
If you’re on a plant-based diet, it is important to take note of the type of plant protein you’re consuming and ensure a well-balanced mix. At the same time, remember to consume enough protein-rich foods to meet your protein requirements daily. You may also want to ensure that each time you consume protein, you have enough to hit the minimal threshold for maximal muscle protein synthesis. To find out more about this, refer to my other post: Muscle talk: protein distribution and amount.