Function of proteins
Proteins are an essential component of any diet and are involved in almost all metabolic processes as a basic building block of all body cells. They make up over 90% of pure body mass (excluding water) and are essential for creating:
- muscles (their preservation and development)
Structure of proteins
Proteins consist of amino acids. At present, there are 22 known amino acids. Out of these, 8 kinds of amino acids are essential for the human body while the rest can be synthesized within the body. Nevertheless, the body should be provided with all the essential amino acids as the body’s own production of non-essential amino acids is done at the expense of the essential ones, which are the actual building material of muscle.
Demand for proteins
The German Nutrition Society (DGE) states that an adult body needs 0.8g of protein per kilogram of body weight a day. This statement has quickly become outdated. Athletes and adolescents have a higher demand for protein compared to inactive adults. An amount of 2g of protein per kg of body weight seems more appropriate and is even exceeded by most athletes.
Protein-rich diets are very filling, which can be very beneficial when you are trying to restrict immoderate eating habits or trying to burn fat. The exact effect of protein is also determined by the type of proteins.
Forms of protein:
Proteins are divided into two categories: fast and slow. Fast proteins such as soy protein isolates; whey protein concentrates and isolates; and in particular whey protein hydrolysates, are characteristic by their large release into the blood stream within a short period of time after consumption. Studies have shown this quick release into the blood stream is essential for synthesis of amino acids and muscle proteins and therefore essential for anabolic processes within the muscle. Fast proteins do not stay in the blood stream for long (up to 3 hours) and therefore they don’t suppress muscle breakdown.
For these reasons slow proteins are better, particularly egg and meat protein and especially casein protein found in milk. These proteins are released into the bloodstream much slower and therefore have a lesser anabolic effect than fast proteins, but they stay there for up to 7 hours, and thus are perfect for use against the catabolic processes within muscles. Long term muscle growth is determined by the muscle protein synthesis but also by the speed of muscle breakdown, where slow proteins are a significant factor.