Consumers want more protein. But is more always better? Not according to science. Science tells us that the quality of the protein is just as important as the amount of protein.
Not all proteins are created equal. When we talk about protein quality, we can’t simply rely on the number of grams on a label; we need to dig into the molecular makeup of those proteins.
Protein is a macromolecule composed of smaller units called amino acids. These amino acids have different structures, acting like building blocks that can be combined in various ways to form unique protein structures with distinct functionalities. Some of these building blocks or amino acids can only be sourced in the diet, classifying them as essential. They are also essential to building important structures like muscle and tissue, and play a role in enzymes, hormones and the immune system.
Understanding protein quality is about looking beyond quantity to see which proteins your body can truly put to work.
What Is Protein Quality?
Quality can be defined in several ways in foods, from texture and flavor to its origins and functionality. At its core, protein quality is a measure of the amino acids a protein source provides and how bioavailable those nutrients are to the human body.
Protein quality metrics rank the proteins based on the content of the essential amino acids present from that dietary source. Therefore, quality measurements include amino acid composition, digestibility of the essential amino acids, and the human population requirement for the essential amino acids per gram of protein consumed.
While there are hundreds of amino acids in nature (some sources cite more than 700), only about 20 make up the building blocks of protein. Of those, nine are considered essential. They include:
- Histidine
- Isoleucine
- Leucine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valine
High-quality proteins deliver these essential amino acids in the right proportions and, just as importantly, in a form your body can digest and absorb efficiently. While protein quantity is important, it’s a protein’s quality that determines its ability to deliver the individual nutrients in sufficient amounts.
That’s where scientific scoring systems come in. Tools like the Protein Digestibility Corrected Amino Acid Score (PDCAAS) and Digestible Indispensable Amino Acid Score (DIAAS) help assess not only whether a protein has the right amino acids, but also whether those amino acids are actually bioavailable to the body. Recently, there is a move towards DIAAS for protein quality as it measures ileal protein after the small intestine. This is because not much amino acid digestion happens in the large intestine.
RELATED: What is DIAAS? Updated Digestibility Scores Explained
Digestibility plays a critical role in protein quality because two products might list the same number of protein grams on their labels, yet contribute very differently toward the recommended daily allowance (RDA) depending on how digestible and usable that protein actually is. A lower-quality protein may technically meet the gram requirement but fall short in terms of what the body can absorb and utilize.
Are Some Essential Amino Acids “More” Essential?
If sufficient amounts of essential amino acids are not consumed through our diets, key biological functions can decline.
A major clinical concern as people age is a condition called sarcopenia, which refers to the gradual loss of muscle mass. Skeletal muscle wasting occurs at a rate of 1–2% beginning at age 50 and may impact 45% of older adults. Exercise and dietary protein intake are both important to stimulate protein synthesis and tip the balance over muscle degradation. Over time, muscle loss can seriously affect physical function and mobility, reduce quality of life, and increase the risk of developing metabolic and cardiovascular diseases. It’s also associated with a higher risk of mortality in older adults.
While all essential amino acids are important for overall health, three of the nine are considered branched chain amino acids (BCAA) which specifically target muscle growth and recovery: Leucine, Isoleucine and Valine.
Leucine draws special attention for its ability to aid in GLP-1 secretion, appetite suppression, wound healing, endurance, immune function and regulating blood sugar.
Comparing Protein Sources: Whey vs. Plant-based
Several forms of protein used in food formulations — including whey, soy and pea proteins — claim to contain all nine essential amino acids, including BCAA, suggesting they also might be equal in quality.
However, just because a protein source may contain all nine nutrients does not mean it contains them in sufficient amounts to benefit the body or that those nutrients can be digested or properly absorbed.
When comparing common protein sources, whey and soy often top the list. Looking at the big picture, whey protein contains higher concentrations of essential amino acids than soy, including 72% more Leucine, 100% more Isoleucine and 109% more Lysine.
| Essential Amino Acids | Whey | Soy |
|---|---|---|
| Histidine | 1.4 (-7%) | 1.5 |
| Isoleucine* | 3.8 (+100%) | 1.9 |
| Leucine* | 8.6 (+72%) | 5.0 |
| Lysine | 7.1 (+109%) | 3.4 |
| Methionone | 1.8 (+500%) | 0.3 |
| Phenylalanine | 3.2 (+28%) | 2.5 |
| Threonine | 5.4 (+135%) | 2.3 |
| Tryptophan | 1.5 (+25%) | 1.2 |
| Valine* | 3.5 (+59%) | 2.2 |
Per 100 grams
*Branched chain amino acid
To obtain the same amount of leucine as whey, a person would need to consume 1.72 times the amount of soy-based protein, and at least twice as much to obtain similar amounts of Isoleucine and Lysine. Methionine, which also aids in protein synthesis, tissue growth and detoxification, would require five times as much soy protein to achieve the same levels.
As a reminder, however, even though a food contains a nutrient, it doesn’t mean it is fully bioavailable. The PDCAAS and DIAAS digestibility scores mentioned earlier play a significant role in ensuring those nutrients are taken up by the body. When comparing whey protein with common plant-based alternatives, the disparity between essential amino acid bioavailability is even more significant.
PDCAAS & DIAAS for Isolated Proteins in Foods
| Food | PDCAAS | DIASS |
|---|---|---|
| Whey Protein (WPI) | 1.00 | 1.18 |
| Soy Protein (SPI) | 0.98 | 0.90 |
| Pea Protein (PPC) | 0.89 | 0.82 |
| Rice Protein (RPC) | 0.42 | 0.37 |
Source (Rutherfurd SM, Moughan PJ.)
Explore a Different Whey
Protein is trending, and science proves that whey protein outshines alternative proteins for nutrition and the benefits to the human body. But consumers and formulators alike also care about flavor, texture and functionality. That’s where whey protein really shines, delivering cleaner flavors and textures that require no or fewer masking agents.
So, why choose whey protein from Grande Custom Ingredients Group over other whey proteins?
Grande WPCrisp® is one example. It delivers high-quality protein fortification with a clean, neutral flavor and consistent texture that sets it apart from other protein crisps. Unlike many crisp ingredients that can taste bitter, grainy, or have unpredictable expansion, Grande WPCrisp offers reliable crunch and uniform appearance — ideal for bars, cereals, clusters and snacks where protein content matters as much as the eating experience.
RELATED: How Are Whey Protein Crisps Made?
Made without chemical modifications or harsh processing, it’s a natural, clean-label ingredient that supports high protein claims without compromising taste or label appeal. Grande carefully manages its production to minimize denaturing during heating, and our milk is sourced with the strictest end-to-end visibility and control.
For formulators looking to create better-for-you snacks that consumers actually want to eat, Grande WPCrisp and other whey ingredients from Grande Custom Ingredients Group offer dependable, real-dairy solutions.
Protein quality starts with its nutritional content and bioavailability, but it doesn’t stop there. Explore the Grande difference for yourself and request a sample of Grande WPCrisp today.
