Hey Boys and Girls!
Today we are talking about the various structures and types of proteins. We will be talking about how different sources of protein are ranked on the protein digestibility corrected amino acid score (PDCAAS), what the criteria are, and what all this jargon basically means for you in terms of fueling for your workouts.
Let’s start off by stating that the most basic component of proteins is the amino acid (complex chains of carbon, hydrogen, and nitrogen). Without getting to technical, it will suffice to say that there are 2 types of amino acids: dispensable and indispensable. Dispensable amino acids are ones that the body cannot manufacture and versely indispensable amino acids are ones that can be manufactured in the human liver. There is a third category known as ‘conditionally indispensable’ which basically means that when the body is under distress, it cannot manufacture enough of a specific amino acid (This point is important to understand in athletes and unique cases, but for now we will stick to indispensable/dispensable).
Now here it is important to point out that there is a distinction between plant proteins and animal proteins. Animal proteins as you can see in the above table tend to ranked a bit higher than plant proteins. This is not to say that incomplete proteins (plant proteins) are less effective than complete proteins(animal proteins). It simply means that plant proteins may not have proper concentrations or lack specific indispensable amino acids and thus have to be paired with other plant proteins to bring the concentrations up to par which would make these complementary proteins.
Now that we’ve gotten a basic idea of different types of proteins, we need to understand how protein is absorbed into the body to have a better idea of how the body absorbs the protein. Absorption of protein happens in the jejunum and the ileum which are located in the small intestine; absorption of the amino acids are in the form of various type of peptide chains. It is important to note that proteins have to be broken down into small peptide chains first before being absorbed. However this does not mean you should go out to but protein supplements that are marketed as ‘predigested’ as the jury is still out on its efficacy. After absorption, some amino acids go straight to the liver and others circulate in the blood.
Now once the amino acids are freely circulating in the blood, they get picked up along the way by skeletal muscle and stored in what is called an amino acid pool within the muscle which then helps synthesis protein (also known as protein anabolism). Now it is important to note that excess amino acids are not ‘stored’ like carbohydrates are for future use. When an athlete undergoes prolonged bouts of stress, amino acids are used to help provide ATP via oxidation (however, this is not what your body ideally wants as the production of ATP via this process is highly inefficient and under extreme circumstances you can see how catabolism would take place. This is the body’s last resort to provide itself with ATP).
Now that we have a basic understanding of what protein is and how it works, we should address some common issues and misconceptions that exist in the fitness community. The first and most obvious suggestion that many people hear is that we should be consuming tons of protein if we want to get stronger or if we want maximize muscular hypertrophy. This thinking is erroneous in that it assumes that since the body absorbs about 5 – 8g of amino acids from protein per hour, that if we increase the supply of protein, the body will naturally want to absorb faster. The problem with this thinking is that although protein synthesis does increase, so does amino acid oxidation and thus net gain is not changed. Since there is no benefit to excess protein consumption, is there a danger? The answer is yes.
Two basic components of amino acids is NH2 and a carboxyl group. Now what happens at the end of the process of breaking down and absorbing these amino acids is the creation of the byproduct ammonia. As you can guess, this byproduct is excreted by the body via urine or feces. The problem is that urea synthesis is capped in each of us, and this cap cannot go up or down. If an individual undergoes a prolonged bout of excessive ammonia in the blood, the results could be fatal.
So when it comes down to what you should be eating in terms of protein intake, the average individual who does not specialize in any sport in particular should aim for approx. 0.8 to 1.2g/kg (you weigh) per day. In terms of post workout protein intake, carbohydrates should be taken alongside protein in order to replenish glycogen stores. Just remember, amino acids are vital for maintaining a healthy immune system, maintaining nitrogen balance (which contributes to maintaining skeletal muscle mass) and maintaining our energy levels!
If this all seems complicated to you, don’t worry – it is. That is why when you are thinking about starting a diet or following a fad you read about in Cosmo, you need to think twice. If the rule of the diet can be summarized in one or two sentences, it is most likely not the best thing for you. Consult a professional dietitian if you are having issues or if you have questions about your food intake.
Team Fit & Fed