Introduction

Proteins consist of several amino acids which are building blocks to help create and maintain every cell in the body. Protein provides many benefits including muscle repair and growth, improved satiety, maintenance of healthy hair, skin, nails, and bones, and supports immune function and hormone regulation.  Our bodies make some amino acids, but others have to come from the food that we eat. The body doesn’t store protein,  so consuming it everyday is important for optimal health and longevity.

Understanding Complete and Incomplete Proteins

Complete proteins contain all 9 essential amino acids: tryptophan, histidine, methionine, threonine, valine, phenylalanine, leucine, isoleucine, and lysine. These are considered high biological value and are crucial for protein synthesis, tissue repair, and nutrient breakdown and absorption. Essential amino acids or “complete proteins” cannot be made by the body, which means they must come from food. Complete proteins are often found in animal sources including beef, poultry, fish, milk, eggs, yogurt, and cheese. However, a few plant sources such as quinoa, amaranth, and whole sources of soy (tofu, edamame, and tempeh) contain all 9 essential amino acids. So, what is the difference between complete and incomplete proteins? Incomplete proteins miss one or more essential amino acids and are found in grains, nuts, seeds, peas, corn, beans, and rice.

Pairing Plant Proteins to Form Complete Proteins

There are many plant-based protein sources available. Common plant proteins include:

  • Legumes (beans, lentils, chickpeas, peas)
  • Nuts (cashews, peanuts, pistachios, almonds)
  • Seeds (pumpkin, sunflower, sesame, flax, chia)
  • Whole grains (quinoa, rice, oats)
  • Soy products (tofu, tempeh, edamame)

Our bodies are able to synthesize complete proteins from plant sources when we consume plant sources throughout the day. It isn’t necessary to consume complementary proteins in the same meal. As long as they are consumed within the same day, the body can combine the incomplete proteins to make complete proteins. The key is to focus on variety in a plant-based diet to ensure adequate protein intake and amino acid balance. Examples of complementary protein pairings:

  • Beans and brown rice
  • Hummus and whole grain pita
  • Peanut butter on whole grain bread
  • Quinoa salad with mixed vegetables and tofu
  • Chia or flax seeds and oats
  • Plant based protein powder and nut or seed butter
  • Collagen and pumpkin seeds/powder/butter

An easy strategy to remember is to combine legumes + grains, nuts, or seeds for complete proteins. Try to eat 30 different plant foods each week for variety, and the opportunity to get all essential dietary amino acids. It’s important to note that because plant proteins are less bioavailable, in a strictly plant-based diet, you may need to eat a bit more to meet the needs that your body has for protein / amino acids.

Conclusion

Amino acids help the body maintain optimal health. The good news is that there are many plant proteins and strategies to incorporate complete proteins into your diet to ensure you are meeting your protein needs. Explore and experiment with different plant-based protein sources and recipes to find a variety of plant protein sources you enjoy! If you want to dive more into your nutrition, book a visit with our Registered Dietitian HERE!