Healthy Nutrition: What is the biological value of a protein?

What is the biological value of a protein?

Aspartic acid molecule. Alpha-amino acid nonessential in mammals. Precursor to several amino acids including methionine, threonine, isoleucine and lysine. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (blue-green), nitrogen (blue) and oxygen (red. Getty Images

When doing research about bodybuilding, healthy nutrition and more, there's a good chance you've run across your fair share of references to proteins. The more you dig, and the mor you learn, there's an even greater chance you've heard some talk about this little thing called the 'biological value of a protein.' 

So, what exactly is the biological value, or 'BV,' of a protein? First, a little background:

Setting the stage...

As most will learn in the early stages of chemistry, the building blogs of all proteins are 'amino acids.' Each protein has its own set of amino acids that are ordered in their own sequence and can be classified as one of two things:

  • Essential
    • Cannot be produced during metabolism by the body
    • Have to be provided via nutritional intake (diet)
  • Non-Essential
    • Produced int he body from other proteins or carbohydrates

There are essentially eight amino acids for adults (Leucine, Isoleucine, Valine, Threonine, Methionine, Phenylalanine, Tryptophan and Lysine) and one additional for children (histidine). 

So, what exactly is the biological value?

The actual biological value isn't necessarily a thing in and of itself, its actually broken down, like essential and non-essential, into two categories that help determine how many essential amino acids a body contains in proportion to what is required of the body. Those two categories?

  • High Biological Value
  • Low Biological Value

When a protein contains the essential amino acids in proportion to what their body requires, they are said to have a high BV. If one or more of those amino acids are missing, or they're present but in low numbers, then that protein is said to have a low BV. 

What exactly makes BV so important?

While other aspects of healthy nutrition (carbs, fats) can be stored in the body for future use, when amino acids aren't used, they leave the body. If you continue to eat a lot of food that has low BV, then the full potential of a protein will not be fulfilled. 

Are there any foods I can eat to ensure I am getting a lot of BV?

There are many foods that can help ensure you have a high BV, as opposed to low. Along with foods that are known to have low value. They are listed below:

  • High BV
    • Meat - Poultry - Fish- Eggs- Milk - Cheese- Yogurt
  • Low BV
    • Plants - Legumes - Graints - Nuts - Seeds - Vegetables