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The science behind the high-quality protein in eggs


Canadians of all ages love eggs for their taste, versatility and nutritional benefits. After all, eggs are packed with essential vitamins, minerals and high-quality protein. What do we mean by high-quality protein? Keep reading to learn about the science behind protein quality and discover why eggs are considered the gold standard in protein.

What is protein and why is it important?

Protein is an essential nutrient that plays an important role in supporting the immune system, muscle growth, hunger signals and many other health benefits. While protein can be found in both animal-based and plant-based foods, its quality varies.

A protein is considered “high-quality” when it contains all nine essential amino acids that can be easily absorbed and used by the body. Eggs are a great example of a high-quality protein as all nine of these essential amino acids are found in eggs in a pattern that closely matches the body’s needs. While the protein in all foods offers health benefits, the protein in certain foods, like eggs, appears to be better digested and processed by the body.1 Protein is so important in fact, that Canada’s Food Guide recommends filling a quarter of your plate with protein-rich foods like eggs as part of a healthy diet.

What are amino acids?

Amino acids are the building blocks that make up protein and play an important role in supporting key bodily functions, such as digestion and tissue repair. Nine of the 20 amino acids are considered essential, meaning our bodies can only get them from our diet. Eggs contain all nine of these essential amino acids, making them what is called a “complete” protein source.

How is the quality of protein assessed?

Nutrition scientists determine protein quality in food by evaluating its digestibility and amino acid composition.2 Thanks to their high count of essential amino acids, scientists have often used eggs as a benchmark for evaluating the protein quality of other foods.3 For example, in one well-recognized measure of protein quality, the essential amino acid score for protein quality in eggs exceeds 100%, compared to 37% for rice and 45% for wheat.4 The body can absorb and use 95% of the protein found in eggs.

Eggs pack a punch in a small package, with 13 grams of protein found in only two eggs. So, the next time you are looking to boost your diet with a healthy dose of protein, look no further than the humble egg. Click here for recipe ideas to help you fuel up on protein with eggs!

  1. The Incredible Egg
  2. Dietary protein quality evaluation in human health, Food and Agriculture Organization of the United Nations, Rome, 2013.
  3. Dietary Reference Intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein,and amino acids, The Institute of Medicine, Washington (DC), 2005.
  4. UN Nutrition