Everybody is talking about proteins and their importance in nutrition. Have you ever wondered what differentiates 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 created equal. Also, we will compare animal protein sources and plant protein sources and their biological value.

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).

The biological value of a protein

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. Some of the most common protein sources are listed in the table below.

Animal protein sources vs plant protein sources

As we saw, the animal protein sources are usually higher in biological value than the plant proteins. That doesn’t mean that plant proteins are the worse source. Lack of one or more essential amino acids in plant proteins can be complemented with another plant based protein to avoid deficiency of some essential amino acid. Only the variety of foods can provide you the best ratios of essential amino acids.

Animal vs. plant protein  from the Center for nutrition studies http://nutritionstudies.org/animal-vs-plant-protein/