Everybody is talking about proteins and their importance in nutrition. Have you ever wondered what differentiate an excellent source of proteins from a good source of proteins? The answer is in their biological value (BV). That means all proteins aren’t equal.
The biological value of a protein has traditionally been defined on the basis of its amino-acid content in relation to human requirements and the suitability for digestion, absorption and incorporation into body proteins (Moore, Soeters, 2015).
BIOLOGICAL VALUE (BV)
Simplified, the biological value of a protein is the ability of its amino acids to be incorporated into body protein. The bigger BV means your body can absorb more amino acids from digested protein. The more amino acids the body absorbs, the more it can use for building muscles, tissues, bones and also for energy production. More muscles increase your basal metabolic rate, so you will burn more calories. This is why you should aim for a quality source of proteins. Of course, proteins don’t only build muscle they also create other body structures such as enzymes, blood, bones etc.
There are 20 amino acids of which 9 are essential (valine, leucine, isoleucine, methionine, phenylalanine, tryptophan, lysine, threonine and histidine). Your body can’t manufacture essential amino acids on its own so essential amino acids have to come from your diet. You can see some of the most common protein sources in the table below.
As we saw, the animal proteins are usually higher in biological value than the plant proteins. That doesn’t mean that plant proteins are the worse source.You can complement lack of one or more essential amino acids in plant proteins with another plant based protein. It helps avoiding deficiency of some essential amino acid. If your proteins come from the plant based sources, you should monitor amino acids intake to avoid lack of the essential amino acids. Only the variety of foods can provide you the best ratios of essential amino acids.