“The anabolic response to protein ingestion has no upper limit.” - Trommelen et al., 2023, Cell Reports Medicine 4, 101324. December 19, 2023 © 2023

I was wrong about protein intake…

And our PROTEIN recommendations as evidence based practitioners should be adjusted.

So, what’s changed?

Well, the above study has just proven that "the magnitude and duration of the anabolic response to protein ingestion is not restricted and has previously been underestimated in vivo in humans."

Put more simply, the results have come back showing the response to protein ingestion during recovery from exercise has NO UPPER LIMIT…

Say again?

What happened in the study?

Subjects were randomised to receive a milk protein concentrate made up of roughly 80% casein and 20% whey protein. The groups received either 25 g, 100 g, or a placebo of 0 g of protein following a single bout of resistance-type exercise.

Plasma and muscle free amino acid concentrations were measured and what they found was...

Muscle protein continued to accrue for not just 4 hours...

...not 8 hours...

but for over a 12 hour period!

I'll say it again.

They consumed 100g of protein and continued to accrue MUSCLE protein over a 12 hour period...

Why is this study groundbreaking?

Well, for a while there was this bro-science belief that our bodies could only handle 25g of protein in one sitting. Bro's were sure there was no point consuming more than 25g of protein in one meal because the body would just 'waste the rest and you’d poop it out. 

Fortunately research swooped in debunking this old wives' tale, enlightening us that indeed, our bodies are wondrous machines. Every extra amino acid that is not fortifying our muscles goes towards revamping our hair, rejuvenating our skin, hardening our nails, and even fuelling the production of those mighty digestive enzymes.

So this revelation is a game-changer… it's just turned the tables, unveiling that massive protein doses keep fuelling your muscles, not just for a mere hour or two, but for a staggering 4, 8, and even 12 hours post-consumption!

True, the pace of protein muscle integration decelerates over these intervals, yet the astonishing fact remains—it continues to climb even a whole half-day after devouring that 100g serving!

So, it’s an absolute nail in the coffin to the myth that you can only handle 25 grams of protein per sitting. This revelation makes it clear as day: loading up on protein in small, frequent doses simply isn't the way to go for maximum absorption.

What does this mean for us now?

Well, we know that total protein over the day is going to be the most important thing. Total daily protein is crowned the king of muscle nutrition, it's going to be the most important thing when it comes recovery and muscle growth. However, relying on a single protein feast might leave you short on maximising those gains. To unlock the full potential of your 24-hour muscle gains we still need to use a smart approach to protein intake not too dissimilar to whats been previously recommended.

But it does give us more flexibility with our intake!

The study shows this taper off between 4-12 hours post-feast, which hints at an opportunity missed if we were to rely on a single bolus of protein for the day. We still need to reignite muscle protein synthesis with an additional boost after your first protein hit if we are to maximise muscle gain.

So, for the savvy muscle architects, aiming for peak growth, the science points towards still getting in 2-4 protein-rich meals spread throughout the day. As long as you've got your total protein needs covered, this strategy ensures your muscles are in a constant state of construction.

So for example a 70kg individual eating 1.6g protein per kg of body weight 112g could split this into 37g for 3 meals or 66g over 2 meals.

Pragmatically for myself and clients it gives further permission to have a protein shake alongside a high protein meal after training to bump up that bolus and maximise muscle building and recovery. 

With all that being said, THE most important thing however, is that you find away to get your total protein in across the day that suits you! Because adherence to a diet is the only thing that’s going to work long term.

Are there any potential limitations?

A couple of things to be mindful of from the study is they used a milk protein that was mainly casein not whey and they have very different amino acid profiles.

1. Casein is much slower digesting so the release of amino acids is much slower than whey protein which could have affected the overall time of muscle protein response.

2. We also need to consider that the protein concentrate may be different from consuming other protein sources like meat, eggs, plant proteins etc.

3. This was done in untrained individuals, so it bears the question would we have seen a difference in people who were consistently training? As we know in athletes for example, the amount of protein required to maintain muscle mass, or not be in a negative nitrogen balance is much greater! *Nitrogen balance is used as an index of protein metabolism. When more nitrogen is gained than is lost, they are considered to be "in positive nitrogen balance" and a state of overall protein anabolism.

SUMMARY:

• There appears to be no identifiable limit to the amount of protein your body can utilise if you extend the time frame long enough.

• Even 100 grams of protein ingested in one sitting won’t lead to amino acid (protein) oxidation or, in plain terms, wasting.

• If you don’t have the luxury of eating many small protein-rich meals daily, GOOD becasue it’s not optimal.

• You’re better off hitting a consistent daily protein intake.