Every bodybuilder knows that protein – the macronutrient responsible for repairing and rebuilding muscle tissue – is vitally important. Without adequate protein intake, gains will be limited, even when following an otherwise excellent training regime.
But how much protein can the body actually absorb in one meal before it goes to waste?
There exist many statements made and taken as truth in the world; that the body can absorb no more than between 30 and 50 grams of protein in a sitting is one.
But is it true?
Before answering, we must examine (on a simplistic level) how protein is digested. A lot goes on between consumption and growth. Protein is ingested in the mouth, where chewing makes short order of the typically dense protein-rich foodstuffs such as meat, fish, eggs, etc. – breaking them down into smaller pieces and particles to aid digestion.
When protein reaches the stomach, the process of digestion begins. Far from being an inert chamber, the stomach is a highly active organ, filled with acids – hydrochloric acid, sodium chloride and potassium chloride – which, together, comprise gastric juice.
When protein is introduced to this acidic mix, a chemical breakdown (“denaturing”) begins. Digestive enzymes – including pepsin, trypsin, protease and peptidase – are activated, continuing the process.
In the duodenum, a segment of the small intestine, myriad enzymes rend the denatured protein into single amino acids and very small quantities of “free form amino acids” (small peptides).
As the digestion process nears completion, the amino acids either enter intestinal cells where they are moved into the bloodstream, or are carried into the liver, where the body destines them based on its needs – for example, the creation of glucose, or muscle protein synthesis.
Now that we have a rudimentary understanding of the protein-digestion process, let us consider, from a few perspectives, the arbitrary 30 to 50 grams per meal figure so parroted in the bodybuilding community.
The digestion of protein is highly complex, involving different types of acids, enzymes and other substances, multiple organs and the innate intelligence of the body.
Given the human organism’s evolved ability to perform such a complicated task, to even “know” which amino acids are required to fulfill exactly which biological needs, the notion that consuming in excess of 50 grams of protein under any condition will result in malabsorption and wastage does not stand to reason.
Speaking from an evolutionary standpoint, consider a society of hunter-gatherers or foragers without the luxury of 24 hour a day access to food, whose eating cycle would fluctuate between short periods of abundance (and consequently, gorging), and long periods of hunger.
To imagine either a conscious decision to curtail protein intake after a set quantity of food was consumed, or that the human species would have evolved to waste this most precious of nutrients seems nonsensical.
Finally, the digestion of protein is a slow, gradual process. Even rapidly digested proteins like whey powder digest at a rate of between 8 and 10 grams/hour, while others may digest as slowly as 3 grams/hour.
Considering this in light of the idea that not more than 50 grams of protein should be eaten at once, does it make sense that one would have to wait 5 hours to eat more protein after taking approximately two scoops of whey?
Furthermore, literature on the topic of protein absorption suggests that the body is capable of digesting rather large amounts – it simply requires more time to do so. “Excess” protein, rather than being wasted (excreted from the colon), is held back from the small intestine by virtue of slowed digestion and metered out in accordance with how much the body requires for specific tasks.
Protein not utilized for muscle protein synthesis (muscle repair, growth and maintenance) is likely utilized for gluconeogenesis (the creation of glucose from non-carbohydrate substrates) in the liver, with only a negligible amount potentially being converted to fat.
Pro Bodybuilder Meals
Take a look at the daily diet of a top level professional bodybuilder and you will soon discover that the human body can absorb more than 30 – 50 grams of protein per sitting.
Do you think that you could win the Mr Olympia by capping your protein intake on each meal?
Jay Cutler, 4 times Mr Olympia is around 280 pounds of muscle mayhem and eats 4000 – 5000 calories per day. His daily protein intake is a whopping 480 grams daily.
Now consider that he eats 6 meals per day, 480 divided by 6 equals 80 grams of protein per meal.
Obviously the large amounts of protein these elite level bodybuilders are eating are going to use.
Eating 60, 70 or more grams of protein poses no problem. Short of unreasonably slamming down 250 gram whey-shakes every day, there is little reason to restrict oneself to an arbitrarily imposed amount of protein at each meal.