A Meal of 100 Grams of Protein Leads to Greater Muscle Protein Synthesis Than 25 Grams, New Study Finds

Key Points:

A new study found that 100 grams of milk protein ingested after strength training resulted in greater and more prolonged muscle growth than 25 grams of protein.
It seems that the more protein you eat in a single meal, the more amino acids are released into your bloodstream, and more are incorporated into new muscle tissue.
The uptake of large, protein-rich meals takes time: after 12 hours, the 100 grams of milk protein was still being released into circulation.
We still know that around 1.6 grams of protein per kilo is enough to maximize muscle and strength gains in most people (but slightly more might be required for jacked individuals). However, this study shows that meal distribution seems to be of minor importance compared to the total protein intake.

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Finally!

That is how I feel about this new study and its results.

Ever since I got interested in the field of bodybuilding and strength training over 20 years ago, there have been discussions regarding the optimal meal frequency and how much protein you can use per meal to build muscle.

A consistent finding in multiple studies has been that about 20 or 30 grams (or 40 in a few cases) of high-quality protein is enough to maximize muscle protein synthesis. That means the building of new muscle protein. I.e., muscle growth.

If you ate more than this, it was still digested and absorbed, but the hypothesis was that it was oxidized for energy or used to build some other tissues in our bodies.

And, because a dose of 20–30 grams of protein is generally digested and absorbed within 3–4 hours, and the average gymgoer wants to get up to about 1.6–2 grams of protein per kilo per day, this leads to a mathematics exercise of fitting high-protein meals into your schedule on fairly precise intervals.

Except this has always seemed a bit … off. (Which is easy to say in hindsight)

Make Protein Make Sense

For one thing, while we shouldn’t make ourselves guilty of the naturalistic fallacy, this doesn’t make sense from an evolutionary standpoint. If humans needed to feed on protein every three to four hours to maintain muscle mass effectively, how would we survive in a time before we could keep our fridges stocked with delicacies?

And how come other animals with similar gastric systems to us can thrive on sometimes very infrequent but very large protein feedings?

And why don’t we see in human studies on intermittent fasting that low meal frequencies lead to far inferior muscle growth?

The Devil Is in the Study Designs

Looking back, it seems that we might have missed this due to minor details in study designs concerning measurements and especially the time frames.

For example, a widely cited study in discussions on how much protein we can use from one meal compared the muscle protein synthesis response in participants eating either 30 g or 90 g of protein from beef.¹

Both doses of protein equally stimulated muscle protein synthesis, with no benefit of the higher dose. The caveat? They only measured for five hours. In hindsight (which is always 20/20), this seems to have been a bit short.

Going to the Bottom with the Issue: 100 Grams vs 25 Grams of Protein, Measured for 12 Hours

A research group out of the Netherlands finally put together a great study to find out what is really going on in our bodies when we ingest large amounts of protein.²

It is beyond the scope of this article to go into their study design in detail (they used four different isotopes of amino acids as tracers: two infused into the cow they later milked to produce the protein (like, wow) and two infused into the participants) but it’s open source, and you can read it here. In any case, here’s the low-down.

Thirty-six participants were put through a full-body strength training workout. They were then allocated to either a placebo group, a group ingesting 25 grams of milk protein, or a group ingesting 100 grams of milk protein.

They worked out, drank their protein (or placebo), and then gave blood samples and muscle biopsies over twelve hours.

The Results

The results were clear: more protein ingested led to

a greater and prolonged appearance of amino acids in the bloodstream,
greater muscle protein synthesis and incorporation of the ingested protein into muscle, and
minor amino acid oxidation, with negligible difference between 25 and 100 g of protein.

More protein ingested led to a greater net balance of protein and more new muscle protein.

In addition, after around five to six hours, the 25 grams of protein had been completely digested and absorbed, with circulatory amino acids and muscle protein synthesis rates going back to baseline (same as the placebo group), but the appearance of amino acids in circulation and muscle protein synthesis was still going strong in the 100 g-group after 12 hours when the measurements were stopped!

After twelve hours, around 4 g out of the 25 g protein shake had been incorporated into skeletal muscle, and this process had plateaued at around the half-time point.

For the high-dose group, around 13–14 g out of the 100 g had been incorporated into muscle, with no sign of a plateau even after 12 hours.

What Does This Mean?

This study strengthens the case that your total protein intake per day is more important than how you distribute it.

It doesn’t seem too important whether you eat many small meals or a few big ones.

Larger meals will stay in your gastric system and be absorbed over a longer time, and the net effect seem to be quite similar.

Note that we don’t know how this affects your results regarding more extreme cases. For example, is just one (very large) meal per day sub-optimal for building muscle compared to spreading your protein out on at least two or three meals? We don’t know for sure.

Still, I hope this brings you some peace of mind, knowing now that meal frequency and protein timing aren’t that time-sensitive. There’s quite a bit of leeway in when you can eat and still build muscle fast, as long as you’re hitting your total protein goal.

Does the Type of Protein Matter?

Before we wrap this up, I want to briefly touch on the subject of protein type.

In this study, they used milk protein concentrate. Milk protein is a mix of whey and casein proteins, of which whey is usually considered a “fast” protein (digests quickly) and casein a “slow” protein (digests slowly). Both, however, are of a high quality in terms of amino acid content and pretty much the gold standard for muscle growth.

Cow milk contains around 80% casein protein and 20% whey protein, making it a mostly slow-digesting protein.

It is plausible that ingesting 100 g of a fast protein like whey leads to higher rates of “waste” (in the context of muscle growth) compared to slow proteins like casein or many other protein foods.

However, one study that measured amino acid appearance in the bloodstream and compared 30 g vs. 70 g of whey protein found that three hours after ingesting 30 g of whey, the amino acid levels in circulation were almost back to baseline, while they were still significantly elevated three hours after ingestion of 70 g of whey.³

Still, taking your entire daily protein intake in a single, massive whey protein shake might not be optimal. Or maybe it doesn’t matter; we don’t know yet.

Get Your Protein On

So there’s that.

Want to learn more about protein? Check out some of our other nifty protein articles below!