To understand this, we must look at the role of protein in the body:
Protein is one of the three macro nutrients: protein, carbohydrates and fats. Macro-nutrients are a class of nutrients that the body needs to survive, they are sources of calories with each of the three serving different functions in our body. They are called macro due to the fact we need them in large amounts. The human body is about 60% water, after that we are mostly protein. Protein is part of every cell, every bone, the blood and every other tissue. No new living tissue can be built without protein – how important is that for building muscle?. Protein constitutes the cell's machinery – they do the cell's work while carbohydrates and fat supply the energy for this work to take place.
The word "protein" was introduced into science by the Swedish physician and chemist Jons Jacob Berzelius (1779-1848) who also determined the atomic and molecular weights of thousands of substances, discovered several elements including selenium, first isolated silicon and titanium, and created the present system of writing chemical symbols and reactions.
The word protein was named by the Dutch chemist Geradus Mulder in 1838 , coming from the Greek word "protos" which means "of prime importance". Our bodies are constantly assemble, break down and use proteins, so this means we must eat enough protein daily so this process can take place. This assembling process occurs through the use of amino acids, the commonly termed” building blocks” of protein. To look at it in a different way, the body will take the 20-22 known amino acids (depending on the source) that are available and create literally thousands of combinations that serve different functions in the body. Of the 20 amino acids, 9 are considered essential because the body can't make them, they must be supplied by the diet. They are: Histidine, Isoleucine, Leucine, Valine, Lysine, Methionine, Phenylalanine, Threonine and Tryptophan. The remaining non-essential aminos are: Alanine, Arginine, Asparagine, Aspartic Acid, Cysteine, Glutamic acid, Glutamine, Glycine, Proline, Serine and Tyrosine.
Protein is essential for growth and the building of new tissue as well as the repair of broken down tissue –as is the case at the end of your workouts. When you hear the term "positive nitrogen balance", a common term used in bodybuilding and weight lifting circles,it refers to being in a state of having enough protein available for the needs of the body and the needs of building muscle. What does nitrogen have to do with protein? According to Tabors Cyclopedic Medical Dictionary, nitrogen is "one of the important elements in all proteins, nitrogen is essential for tissue building." What is more important is that nitrogen is a direct measurement of protein levels in the body.
So, for the most part we are told to take in enough protein from both whole food sources and supplement sources to maintain a positive nitrogen balance ( or positive protein balance) because your body is actually in an anabolic phase in this state, where a negative nitrogen balance, from lack of adequate protein, indicates a catabolic state. Anabolic is defined as “ the phase of metabolism in which simple substances are synthesized into the complex materials of living tissue”. Catabolic is defined as “ The metabolic breakdown of complex molecules into simpler ones, characterized by destructive metabolism”. It's for this very reason that taking in enough protein through out the day,and the timing of these protein meals, is so important: not enough protein, and your body begins to break down muscle tissue to meet the it's demands which, again, means the constant assembling, breaking down and use of proteins (in the form of amino acids, remember). So we can see the importance of adequate protein in our diets and the consequences of not enough protein through-out the day.
Most modern authorities agree: you need at least 1 gram of protein per pound of body-weight with many suggesting as much as 1.5 grams per pound. This should be divided over 6 small meals or feedings. Put another way, you should be eating protein every 3 hours. Why? As talked about above, the body will use amino acid sequences or chains to perform a myriad of functions all day long. To make these chains, it will pull protein in the form of amino acids from your food. If enough protein is not available, it will pull what it needs from muscle tissue. So, with all of that, protein supplements are very simply, protein sources available primarily in powder form. The critical point to understand about protein powders is the ability of convenience. Now that we understand why properly timed protein intake is so important it should be clear why powders can be so useful – they allow quick and easy access to a quality protein source. As well, in many instances, such as in your post workout shake and morning protein intake, speed of digestion is crucial. Whole food simply does not digest fast enough.
Does that mean they should replace whole food? No,it does not, but they are justified by the fact we can’t always get to whole food and there are times we need a more specialized use which is best fulfilled from supplements.