Protein Absorption – Part 1
Protein Absorption – how much protein can your body absorb at one time? You know how it is – you just powered through a brutal workout. Should you drink a post-workout shake? How much protein powder should you use? For decades, you have been told that eating more than 30 grams per meal is a waste of time. It’s time to set the record straight! Recent research reveals that your digestive system is an incredibly adaptable machine that doesn’t waste protein. So where does the excess go? In this special Series, I will answer that question and more! Check out Part 1 now, then jump right into Part 2!
Protein Absorption – A Quick Recap!
| Core Question | The Old 20-30g of Protein Myth | The Modern Scientific Reality |
| How much can you absorb at once? | Only 20 to 30 grams per sitting. | Virtually unlimited. The gut slows down digestion via a “gastric brake” to process massive doses. |
| How long does muscle building last? | It shuts off completely after 3 to 5 hours. | A large protein dose keeps the body in a hyper-extended anabolic window for 12+ hours. |
| What happens if you eat meals frequently? | It’s only done because you can’t digest big meals. | It creates an “Anabolic Overlap”, ensuring a continuous, heavy stream of amino acids for maximum recovery. |
| Is excess protein burned as direct fuel? | Yes, it is a great source of training energy. | No. The liver only burns off excess dietary amino acids to safely clear nitrogen waste, shifting your body away from burning fat. |
| What is the best way to hit your daily macro goals? | Force yourself to choke down massive whole-food meals. | Spread your target across 5 to 6 convenient meals, using apremium powder like Hi-Tech Precision Protein to hit your protein goal. |
What Affects Protein Absorption?
First off, let’s define protein absorption. This is the process of protein breaking down into amino acids and being carried into the bloodstream. As many of you know, there are 20 proteinogenic amino acids. These amino acids are major components of protein, which is why they are commonly called “the building blocks of protein”.
OK, so once your protein source is consumed, it will undergo a sequence of digestive processes. This allows the protein to be absorbed and then transported throughout your body. An important point to remember is that once absorbed, not all the protein is used for muscle growth. In the case of “excess” protein, it will be used for other metabolic functions such as recovery.
How Much Protein Is “Excess” Protein?
The idea that the body can only absorb and use 20-30 grams of protein for muscle growth is a myth. Let’s clarify: some authorities may state that the effective amount of protein for muscle growth is 20-30 grams, and any excess is wasted.
Recent, groundbreaking science has officially taken protein absorption past that 20–30 gram cap. The idea that 20–30 grams is the maximum usable amount for muscle growth is incomplete because it mistakes a short-term measurement for a hard physiological ceiling. (1)
The Evolution of the Science
1. The Old Rule: The 30-30 Grams Per Meal Cap
Older studies frequently concluded that 20 to 30 grams of high-quality protein fully maxes out Muscle Protein Synthesis (MPS). Anything consumed beyond that amount was believed to be oxidized for energy or turned into urea. However, these studies had a major flaw: researchers stopped tracking the participants’ bodies after only 3 to 5 hours. (2)
2. The New Science: Extended Anabolism
A landmark 12-hour isotope tracer study completely upended this rule. Researchers compared a standard 25-gram dose of protein to a massive 100-gram dose after training. (1)
The results showed that 100 grams of protein triggered a significantly greater and more prolonged anabolic response that lasted well past 12 hours. The body simply slowed down its digestive track to steadily release those amino acids, continuously building and repairing muscle over a much longer timeframe. Less than 15% of that massive dose went to waste or oxidation. (1, 5)
3. Beyond Muscle Building
The take-home point is that the body does not waste the excess; it just takes longer to distribute it. Most excess protein is utilized for vital functions—including immune health, cellular repair, and hormone production.
4. Where Does the “Excess” Actually Go?
- Sustained Muscle Building: Prolonged release of amino acids keeps the body in an anabolic (muscle-repairing) state for hours longer than previously thought.
- Systemic Repair: Amino acids are directed to non-muscle tissues (immune cells, organ health, skin, hair, and enzymes).
4. The Practical Application
- Total Daily Intake Rules: Total daily protein intake remains the undisputed king of muscle growth. If you don’t hit your target number by the end of the day, your gains will suffer.
- The Power of Consistency: While the new science shows your gut can eventually slow down to process large individual doses, spacing your protein out over 5 to 6 small meals is the most reliable way to hit those high daily targets.
- For anyone with a hectic lifestyle, trying to choke down two or three massive, 80-100 gram whole-food meals is completely unrealistic. Dividing that quota into smaller, convenient feedings is a key to consistency.
A Modern Marketing Claim – Is Protein Used For Energy?
This is a big pet-peeve of mine, as I see ads all the time that claim “protein gives you energy”. Let’s be clear, the body aggressively prioritizes carbohydrates and fats for your daily energy needs, using protein only minimally (around 1% to 5%) under normal conditions. (3)
What Actually Happens to Excess Dietary Protein
When you consume a massive amount of protein as part of your normal meals, your body does not immediately start burning those amino acids for “energy” instead of your carbs. (4)
Instead, the process works as follows:
- The Structural Cut-off: You eat a high-protein meal. Your body uses what it needs for muscle protein synthesis, organ repair, immune function, and enzymes.
- The Leftover Pool: The excess amino acids cannot be stored for later. They must be processed by the liver via amino acid oxidation.
- Protein as a Fuel Source (Gluconeogenesis): The body does not want to use protein as a primary fuel source since it prefers carbs/fats.
- Protein as Bio-Waste (Amino Acid Oxidation): When you overeat protein, the body burns the excess not because it needs to use them for energy, but because it has to destroy the leftover amino acids that it cannot store.
Ah, but let’s be clear! If you can eat 100 grams of protein in one meal and all of that will go towards anabolic processes, how much would you have to eat before you ever reach a point of protein being used for energy? Most likely, more than you typically ever would!
That means that the idea of “big protein energy” as I have seen advertised recently is nonsense. There is no reason companies should even be advertising that since carbohydrates do the job just fine.
I’m On A Diet, I Keep My Carbs Low!
Even for those lifters and other individuals following a low-carb diet, you should be eating more carbs in the hours around your workouts. This goes back to a point I have been pushing for a while: in the hours before, during, and after your workouts, you should be consuming 50% of the day’s carbohydrates and 100% of the day’s simple carbohydrates, even if that means adding some carbs to your diet. This means that you will have enough ATP energy from carbs to power you through your workouts.
Summary
In Part 1 of my Series on Protein Absorption, we covered quite a bit of ground. In Part 2, we’ll continue to explore this fascinating topic. Before you check it out, stop by illpumpyouup.com and see all we have to offer. Then when you’re ready, go to Part 2 and find out more!
References:
- https://www.sciencedirect.com/science/article/pii/S2666379123005402
- Schoenfeld, B. J., & Aragon, A. A. (2018). How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution. Journal of the International Society of Sports Nutrition, 15, 10. https://doi.org/10.1186/s12970-018-0215-1
- https://www.sciencedirect.com/science/article/pii/S2405457725032139
- Bender D. A. (2012). The metabolism of “surplus” amino acids. The British journal of nutrition, 108 Suppl 2, S113–S121. https://doi.org/10.1017/S0007114512002292
- Trommelen, J., van Lieshout, G. A. A., Nyakayiru, J., Holwerda, A. M., Smeets, J. S. J., Hendriks, F. K., van Kranenburg, J. M. X., Zorenc, A. H., Senden, J. M., Goessens, J. P. B., Gijsen, A. P., & van Loon, L. J. C. (2023). The anabolic response to protein ingestion during recovery from exercise has no upper limit in magnitude and duration in vivo in humans. Cell reports. Medicine, 4(12), 101324. https://doi.org/10.1016/j.xcrm.2023.101324
By Jim Brewster