For decades, nutrition science has relied on PDCAAS and DIAAS to measure protein “quality.” These scoring systems are quoted everywhere, on supplement labels, in academic journals, and in conversations at your gym.
They sound scientific. They seem legitimate. But there’s one big problem:
They weren’t built for performance. They were built to fight malnutrition in kids.
And if you’re eating for strength, recovery, or muscle health, those metrics are not just outdated, they’re misleading.
Even the NIH questions this measurement scale
https://pubmed.ncbi.nlm.nih.gov/10867064/
Although the principle of the PDCAAS method has been widely accepted, critical questions have been raised in the scientific community about a number of issues. These questions relate to 1) the validity of the preschool-age child amino acid requirement values, 2) the validity of correction for fecal instead of ileal digestibility and 3) the truncation of PDCAAS values to 100%.
Let’s Back Up: What Are PDCAAS and DIAAS?
PDCAAS: Protein Digestibility-Corrected Amino Acid Score
Introduced in 1991 by the FAO/WHO, PDCAAS measures two things:
- How much of a protein you can digest
- How well its amino acid profile matches the needs of preschool-aged children
That’s not an exaggeration, the benchmark profile is literally based on 2- to 5-year-olds. This age group was considered most at risk for protein deficiency globally at the time. So if a protein had just enough of each amino acid to prevent deficiency in a small child, it earned a score close to 1.0.
DIAAS: Digestible Indispensable Amino Acid Score
DIAAS, introduced by the FAO in 2013, attempts to improve on PDCAAS by:
- Measuring digestibility at the end of the small intestine (instead of total digestibility)
- Looking at each amino acid individually, rather than grouping them together
- Using slightly updated reference values for different age groups
But here’s the kicker: DIAAS still uses minimum survival requirements, not optimal performance needs. The benchmarks are based on the lowest amount of amino acids needed to avoid deficiency. Not the amount needed to thrive, recover, or build muscle.
So What’s the Problem?
- ❌ They’re Not Based on Human Muscle
- ❌ They Penalize Some Proteins Unfairly
- ❌ They Ignore Amino Acid Proportions
- ❌ They Favor Isolates Over Whole Foods
Why This Matters
Both PDCAAS and DIAAS were designed with the primary goal of addressing protein malnutrition in vulnerable populations, particularly children. They assess whether a protein source meets the minimum essential amino acid requirements to prevent deficiency diseases.
- Not Tailored for Muscle Protein Synthesis
- Overemphasis on Limiting Amino Acids
- Capping of Scores
…these systems fall short. They don’t account for:
- The exact EAA profile your muscles require
- How amino acids are actually used, not just absorbed
- Balance and synergy between amino acids
Let’s Look at the Numbers
| Protein Source | Bioavailability (PDCAAS/DIAAS) | Notes |
| Whey Isolate | 1.00 / 1.14 | Very digestible, poor amino acid balance for muscle |
| Milk (Whole) | 1.00 / 1.05 | Balanced animal protein, good digestibility |
| Chicken (White) | ~0.95 | Strong match, highly usable |
| Pea Protein | ~0.70–0.89 | Moderate digestibility, low methionine |
| Rice Protein | ~0.59 / ~0.37 | Penalized for low lysine in DIAAS |
| Soy (Tofu Firm) | ~0.91 | Best of the whole-food plant options |
| Quinoa | ~0.76 | Strong amino acid balance, moderate digestibility |
Whey Gets a Free Pass, But It Shouldn’t
- Whey is low in histidine, threonine, and phenylalanine compared to human muscle
- It’s imbalanced, even if it’s highly absorbed
- That’s why its Match Rate™ is just 48.5%
So yes, your body absorbs whey quickly, but you can only use half of it for building muscle. That’s not performance. That’s protein waste.
The Need for a New Metric
- Focuses on amino acid balance relevant to human muscle tissue
- Considers the actual utilization of amino acids for performance and recovery
- Goes beyond preventing malnutrition and aims to support peak performance and health
What Is Match Rate™, and Why It Changes Everything
Match Rate™ is a modern way to evaluate protein quality based on:
- How closely the amino acid profile matches human muscle
- How well it supports tissue building and recovery
- What percentage of that protein your body can actually use
It doesn’t just ask “Did your body absorb it?”, it asks “Can your body build with it?”
This is why Match Rate™ is a better measurement of how well a protein source aligns with human physiological needs. That’s the difference between eating for numbers… and eating for results.
Match Rate vs. Bioavailability, Side by Side
| Metric | Measures | What It Tells You |
| Bioavailability | Digestion & absorption | “Did your body absorb the protein?” |
| Match Rate™ | Amino acid alignment | “Can your body use the protein to build?” |
Bioavailability is like tracking a delivery truck. Match Rate™ is opening the box and finding exactly what you needed.
| Protein Source | Match Rate™ | Bioavailability (PDCAAS/DIAAS) | Notes |
| Whey Isolate | 48.5% | 1.00 / 1.14 | Very digestible, poor amino acid balance for muscle |
| Milk (Whole) | ~70–75% | 1.00 / 1.05 | Balanced animal protein, good digestibility |
| Chicken (White) | 81.4% | ~0.95 | Strong match, highly usable |
| Pea Protein | 54.2% | ~0.70–0.89 | Moderate digestibility, low methionine |
| Rice Protein | 46.8% | ~0.59 / ~0.37 | Penalized for low lysine in DIAAS |
| Soy (Tofu Firm) | 65.7% | ~0.91 | Best of the whole-food plant options |
| Quinoa | 82.6% | ~0.76 | Strong amino acid balance, moderate digestibility |
| NutriMatch™ | 96.2% | ~0.95 estimated | Plant-based blend engineered for muscle match |
NutriMatch™: Built for Muscle, Not Just Digestion
- Real-world amino acid precision
- Actual alignment with human muscle
- Less protein wasted, more results per gram
It’s clean, plant-based, and tuned to match you, not a child’s nutrition chart.
Conclusion: Time to Upgrade How We Think About Protein
Bioavailability metrics like PDCAAS and DIAAS had their place. They helped us fight protein deficiency in the 20th century.
But in the 21st? We need better.
If you’re focused on performance, recovery, or long-term health, you need more than “absorbable.” You need usable. Efficient. Smart.
You need Match Rate™.
