Theories on Protein Intake
I am not a scientist, but a bodybuilding theorist, with some very smart friends. So I’ve had long discussions with some very bright people regarding protein intake, digestion and eventual muscle assembly including; Dr, Scott Connelly from MET-Rx and Jeff Feliciano…who has researched protein dynamics for over 25 years. After many conversations here are MY thoughts.
From an evolutionary perspective it appears that the amount of protein eaten per meal isn’t that big of a deal relative to building muscle mass. For example, if you were in the wild and feasted on 3-lbs of tissue protein (your last kill) in an 12 hour sitting, it may take until the next evening for it all to be digested, but not much would be wasted. This is not to say you wouldn’t feel a bit sluggish if you had to run with a belly full of meat, but eventually the nitrogen is hardly washed out. The key factor here is that the body is well adapted to dismantling tissue proteins and thus the digestive tract has a built in time scale that inhibits protein waste (note: it may not build more muscle but that isn’t the only metabolic need either).
It appears that this scenario changes to some degree when consuming large amounts of whey protein at one sitting. Why? Because the amino acid in-flux from whey is very fast (like fast acting carbs), which in turn overrides some of the time sensitive work done by your digestive tract. The result is that you may be setting the stage for an abnormally high amount of gluconeogenesis to occur, which is the process of synthesizing glucose from non-carbohydrate sources.
Think of protein digestion and its proper use like an assembly line for cars. If some of the parts go by too fast, not as many cars (muscle or hormones etc.) can be built, and some of the spare parts (excess amino acids) will be used for other things. In our analogy €˜other uses’ could be to make glucose from amino acids, which is actually happening all the time at some level. Not very economical!
The digestive tract is highly adaptive, and is quite well equipped for native proteins, the kind that must be ripped up and put back together. This time dependency is consistent with our muscle building machinery, because the process of myofibrillar protein turnover is very slow, which means that protein synthesis is more apt to be affected by long-term alterations in protein (amino acid) supply. Simply put, the body will adapt to large influxes of nitrogen and make the best use of the available amino acids. So if you get enough protein in per day, and your plasma levels of amino acids remains stable you’re good to go.
Now, from an economic and convenience standpoint, the most fundamental goal you must have is to ensure that you eat enough total protein calories each day, and every week, so that you can support the very gradual increase in myofibrillar protein mass stimulated by your workouts.
In modern times however, eating multiple meals per day serves many other functions such as giving you a target time to supply your body with proper ratios of protein, carbs, fat and water to keep hormone levels optimized. I prefer eating more frequently for many reasons, and alter the macronutrients according to pre and post workout etc.
For fun just ask yourself what happens if you miss hitting your protein goals for more than a few days. The answer is you begin to crave the protein, because your body knows what it needs.
Bottom line; the question of €˜how much protein can be digested’ is pretty pliable, meaning your digestive tract will adapt. On the other hand, your training is what altars your muscles net protein needs, and eventual gains.
