Biological value is a measurement that determines whether the body has use for a nutrient or if it is not essential to survival. All proteins are made from amino acids; when a protein has the right amount of key amino acids, it is a high biological value protein. When a protein has a low value, it needs to accompany another complementing protein to help the body.
Because the amino acids that make up proteins are numerous and people have different needs, biological value is slightly subjective. Most people need the same high biological proteins to build healthy bones and muscles. How people get their protein varies. Many vegetarians receive all the essential amino acids that their bodies require without having to eat meat. They do this by substituting the amino acids missing in vegetables with nuts, beans and legumes.
A high biological value or low biological value in a protein does not make it better or worse than any other nutrient. However, knowing whether a protein has a high biological value helps a person make effective decisions when it comes to dietary consumption. High biological value proteins come from animal sources, while low biological value proteins come from plant life.