Complete Protein Per Calorie Is Only Half the Story

Andrew Huberman’s nutrition chapter in Protocols is built around a simple ranking tool: complete protein per calorie.

He calls it a high CPC ratio. The protocol is to eat that kind of protein at each full meal. His contrast is blunt. Chicken delivers 28 grams of complete protein in 150 calories. Beans and rice deliver 6. Same calorie budget. Very different amount of usable building material.

That is a density argument, and it is a good one. It is also incomplete.

Two foods can post the same protein-per-calorie number and still not do the same job. One can miss an essential amino acid. One can be poorly digested. One can sit in the gut for hours while the other is already in the blood. Labels show grams. They do not show how many of those grams are essential, digestible, and available when you need them.

There is no official FAO or WHO score named “bioavailable amino acids per calorie.” The pieces exist. Combining them is the useful next step.

Huberman’s CPC ratio, in plain numbers

CPC is grams of complete protein divided by calories. Complete means the food supplies all nine essential amino acids the body cannot make.

Using his own examples:

Food	Complete protein	Calories	Protein per 100 kcal
Chicken	28 g	150	18.7 g
Beans and rice	6 g	150	4.0 g

Chicken is about 4.7 times more protein-efficient in that pairing. That is why the protocol exists. If you are trying to hit roughly a gram of protein per pound of body weight without blowing the calorie budget, density decides whether the day works.

The ward data for surplus composition is in Calories Decide the Fat. Protein Decides the Muscle.

Huberman’s high-CPC list already includes whey, alongside poultry, lean red meat, fish, shellfish, plain full-fat Greek yogurt, and cottage cheese. The target sitting is 30 to 50 grams of that protein at each meal or snack. Leucine is the amino acid he flags as the mTOR trigger for muscle protein synthesis.

So the book already put whey in the winner’s circle on density and completeness. The open question is the second half of the sentence: bioavailability.

Completeness, digestibility, and speed are not the same thing

Three different questions get mashed into the word “bioavailable.”

1. Does the protein contain the essential amino acids?

Nine amino acids have to come from food. If one is short, the extra grams of the others do not fully convert into human protein. That is why collagen can look high-protein on a label and still be a weak muscle protein. It is also why beans and rice together can be complete while either one alone is not.

2. Does the gut actually absorb those amino acids?

The current scientific standard is the Digestible Indispensable Amino Acid Score, or DIAAS, recommended by the FAO in 2013 to replace PDCAAS. PDCAAS used fecal digestibility and capped scores at 1.00, which made egg, milk, whey, and soy look identical at the top. DIAAS measures individual essential amino acids at the end of the small intestine and does not cap the score. That lets high-quality proteins rank above 100.

Typical published ranges:

Protein	Approx. DIAAS	Notes
Whey protein isolate	~1.09–1.25	Excellent; valine often limiting
Milk protein	~1.14–1.18	Excellent
Chicken breast	~1.08	Excellent
Egg	~1.13	Excellent
Soy isolate	~0.90	High, sulfur amino acids limiting
Pea concentrate	~0.82	High, sulfur amino acids limiting
Rice concentrate	~0.37	Lysine limiting

Whey isolate is already at the ceiling of official protein quality. That matters, because it sets the honesty line for any product built from whey.

3. How fast do those amino acids appear in blood?

DIAAS does not measure speed. Two proteins can have the same digestibility and still produce very different plasma curves. Intact whey isolate is fast. Hydrolyzed whey isolate is faster still, because a large share of the protein is already in di- and tri-peptides that use the PEPT1 intestinal transporter instead of waiting on full gastric digestion.

Speed is not the same as “more amino acids absorbed.” Intact whey isolate is already about 95 to 99 percent digestible. Hydrolysis does not invent a higher DIAAS. It changes kinetics: how quickly the essential amino acids and leucine show up where muscle can use them.

That distinction is the whole article.

A working metric: digestible essential amino acids per calorie

If you want one number that combines Huberman’s density idea with official quality scoring, use this:

DEAC = digestible essential amino acids per 100 calories

DEAC ≈ (protein grams × essential-amino-acid fraction × DIAAS) ÷ calories × 100

A simpler consumer version is quality-adjusted protein per calorie:

Quality-adjusted CPC = (protein grams × DIAAS) ÷ calories

Neither is an official regulatory score. Both are honest arithmetic from published pieces. They stop you from treating 30 grams of rice protein like 30 grams of whey, and they stop you from treating a 400-calorie burrito like a 160-calorie shake just because both say “protein” on the package.

Using typical published values for foods, and current product CPC for the Progenex lineup:

Food or serving	Protein / 100 kcal	Complete	Approx. DIAAS	Quality-adjusted protein / 100 kcal	Speed
Chicken breast (Huberman example)	18.7 g	Yes	~1.08	~20.2 g	Slow to moderate
Nonfat Greek yogurt	~18–20 g	Yes	~1.15	~21–23 g	Moderate
Sustain	20.8 g	Yes	whey-class ~1.09	~22.7 g	Fast
More Muscle	22.1 g	Yes	whey-class ~1.09	~24.1 g	Faster (peptides)
Recovery	17.7 g	Yes	whey-class ~1.09	~19.3 g	Faster (peptides)
Whole egg	~8–9 g	Yes	~1.13	~10 g	Moderate
Cooked black beans	~7 g	No (methionine)	~0.65	~4.5 g	Slow
Beans and rice (Huberman contrast)	4.0 g	Complementary	mixed, well below 1.0	~2–3 g	Slow

Read the table the way Huberman wants you to read food. Density first. Then quality. Beans and rice are not “bad.” They are an expensive way to buy essential amino acids if the job is muscle, recovery, or holding lean mass in a calorie deficit.

Leucine per sitting tells the same story in the language of muscle protein synthesis. Whey is typically about 10 to 12 percent leucine by protein weight. Chicken is lower. Combined plant meals are lower still. A 25-gram whey serving commonly lands in the 2.5 to 3.0 gram leucine range, which is the meal threshold most hypertrophy research uses as a practical trigger. That is why Huberman can put whey on the same list as chicken and yogurt without stretching the science.

Where whey already wins both of Huberman’s axes

Whey isolate is a complete protein. It is leucine-dense. Its DIAAS sits with milk, egg, and chicken at the top of the scale. And because fat and lactose have been removed, the calorie cost per gram of protein is low.

That is why whey shows up in Huberman’s high-CPC source list. It is also why a flavored isolate like Sustain lands at 20.8 grams of protein per 100 calories — above Huberman’s chicken example — without asking you to cook.

More Muscle sits higher still at 22.1 grams per 100 calories, with 31 grams in the serving. That is one of Huberman’s 30-to-50-gram sittings at a better CPC than the chicken line he used to explain the idea. Recovery is 17.7 grams per 100 calories with 23 grams in the serving: still in the same class as chicken, built for the minutes after training rather than as the day’s largest protein hit.

The product story is not “we beat chicken on official protein quality.” Chicken is already excellent. The product story is that you can hit Huberman’s sitting, at chicken-level or better calorie efficiency, with a complete essential amino acid profile that plant scoops usually do not match gram-for-gram.

What hydrolysis adds — and what it does not

More Muscle and Recovery are not generic whey. They start as whey protein isolate, then are enzymatically hydrolyzed into di- and tri-peptides. Sustain stays an intact isolate: clean, flavored, built for the day’s other protein hits.

What hydrolysis supports:

Faster appearance of amino acids and peptides in plasma. Morifuji and colleagues compared intact and hydrolyzed whey and soy in humans. Hydrolysates raised plasma amino acids faster. Whey beat soy on essential amino acids and BCAAs. Hydrolysates raised the dipeptides Val-Leu and Ile-Leu. Whey hydrolysate produced the largest insulin response.

A functional recovery finding after muscle-damaging work. Buckley and colleagues ran a double-blind trial after 100 maximal eccentric knee extensions. Subjects then drank water, 25 grams of intact whey isolate, or 25 grams of whey isolate hydrolysate. Peak isometric torque dropped about 23 percent in all groups. It recovered fully by 6 hours in the hydrolysate group. It stayed suppressed at 6 hours in the intact isolate and water groups. Soreness did not differ. This is a force-recovery result, not a “more muscle on the scale” result. The hydrolysate arm was small (six people). It is still the cleanest published comparison of hydrolyzed versus intact isolate after eccentric damage.

What hydrolysis does not do:

It does not raise DIAAS above whey isolate. Intact isolate is already excellent.

It does not let you skip total daily protein. Huberman’s 1-gram-per-pound logic still governs the day.

It does not make a 10-gram scoop equivalent to a 30-gram sitting. Dose still matters.

Matched grams are not utilization. That layer is in Same Grams. Different Outcome.

It is not a universal proof that every hydrolysate beats every isolate for muscle protein synthesis. Some trials show faster aminoacidemia. Some show similar body-composition outcomes when total protein is matched. The claim that holds is speed plus the Buckley force-recovery data, not “this builds more muscle than all other whey.”

That is the third axis Huberman’s chapter does not spend time on. Density and completeness get you the right food class. Kinetics get you the right form when the use-case is the session you just finished, or the next one later the same day.

How to use the three products inside Huberman’s protocol

Huberman’s nutrition chapter is not a supplement pitch. The backbone is unprocessed food, protein first, and calories that match the goal. Powder is there to make the protein target possible.

A clean split:

Sustain for the day’s isolate sittings. 25 grams of whey protein isolate. Flavored, no added sugar, built to drink. Use it when you need a clean protein hit and you do not need peptide speed: mid-morning, afternoon, travel, the sitting that would otherwise get skipped. See also protein hits beat protein dumps.

More Muscle for the larger daily hit. 31 grams of hydrolyzed whey isolate. That is one of Huberman’s 30-to-50-gram sittings in a single shake, at 22.1 grams of protein per 100 calories. Use it at breakfast, between meals, or as the protein course when whole food would blow the calorie budget.

Recovery immediately after training. 23 grams of hydrolyzed isolate, built for the minutes after the session. This is the kinetics tool. The job is not “replace dinner.” The job is to put digestible essential amino acids into circulation when the tissue has just been loaded. Do not miss the dose: the #1 post-workout nutrition mistake.

Whole food still does the majority of the day’s eating. Whey does the sittings that food does not cover cleanly: early morning, post-workout, travel, appetite crashes, cuts.

If the comparison that matters to you is plant protein at equal labeled grams, that is a different article: plant proteins can't compete. At equal grams, most plant isolates deliver fewer essential amino acids and less leucine, and their DIAAS is lower. You can make plant patterns work. You spend more calories and more total protein to do it. That is CPC and DIAAS talking, not brand preference.

What to look at on any protein label

Ignore the front of the bag. Read four numbers.

1. Protein grams per serving.
2. Calories per serving. Divide. That is your CPC.
3. Whether the source is complete. Whey, milk, egg, meat, and soy isolate usually are. Collagen, gelatin, and most single plant flours are not.
4. Form. Concentrate, isolate, or hydrolysate tells you about lactose, fat, and speed. It does not by itself tell you the dose is high enough.

If a serving needs 250 calories to deliver 20 grams of incomplete protein, it loses Huberman’s test before bioavailability ever enters the conversation. If it delivers 25 to 31 grams of complete, digestible protein in a lean calorie budget, it passes the density test. If those grams are already in peptide form, it adds the speed test.

That is the combined metric in practice: complete protein per calorie, corrected for what the body can actually use, then judged by how fast that dose shows up.

Huberman gave the public the first half. The second half is why isolate-level whey sits at the top of the food list, and why a hydrolyzed isolate is the athlete version of the same idea.

FAQ

Is there an official “bioavailable amino acids per calorie” score?

No. DIAAS scores digestible essential amino acids per gram of protein. CPC scores protein per calorie. Multiplying them is a useful working metric. It is not an FAO standard.

Does hydrolyzed whey have higher DIAAS than regular whey isolate?

Not in any meaningful published sense. Isolate is already at the top of the scale. Hydrolysis changes how fast amino acids appear, not the official quality score.

Why not just eat chicken?

Do. Chicken is the food Huberman used as the high-CPC example, and its DIAAS is excellent. Powder exists for the sittings where chicken is impractical: post-workout, first meal, travel, calorie-capped days.

How much protein per meal?

Huberman’s range is 30 to 50 grams of high-protein food per sitting, with a daily target near a gram per pound of body weight. A More Muscle serving covers one of those sittings. Sustain covers a smaller daily sitting. Recovery covers the post-training sitting.

Does faster absorption mean more muscle?

Faster aminoacidemia is not automatically more hypertrophy over a full training block. Total daily protein, dose per sitting, and training still dominate. The published edge for hydrolysate versus intact isolate is recovery of force after eccentric damage, plus faster plasma amino acids and peptides.

What is the difference between Sustain, More Muscle, and Recovery?

Sustain is whey protein isolate for daily protein hits. More Muscle is a larger serving of hydrolyzed isolate for the day’s main shake. Recovery is hydrolyzed isolate dosed for the session you just finished.