Protein Quality vs Quantity: Why There’s More to Protein Than Grams

Protein quantity has historically been the measure of product effectiveness in the supplement and functional food industry. But as alternative protein sources become available, manufacturers and consumers alike are starting to realize that there’s more to protein than grams. In this post, we break down the difference between protein quantity and quality and its implications for manufacturers.

Amino Acid Profile

Amino acids are required for the synthesis of body protein and other important nitrogen-containing compounds, such as creatine, peptide hormones, and some neurotransmitters.

There are 20 amino acids, 9 of which are considered essential amino acids:

  • Histidine
  • Isoleucine,
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

A protein source is considered complete when it provides all of the essential amino acids in relatively equal quantities.

When it comes to protein supplements and functional foods, the completeness of the protein source’s amino acid profile is just as important as the quantity of protein being consumed. That’s because a large quantity of protein with an incomplete profile doesn’t provide all of the acids required for the synthesis of muscle protein.

With the exception of soy, most plant-based proteins are an example of a protein source with an incomplete amino acid profile.

Traditional whey and native whey protein (NWP) both have complete amino acid profiles. However, NWP has higher levels of key acids. For example, NWP has up 17% higher levels of leucine, which is vital in muscle synthesis.

NWP is also far more efficient for muscle cells than amino acids added directly to a traditional whey protein. Its higher bioavailable leucine and unique amino acid composition help to trigger and support muscle protein synthesis.

Protein Availability

Providing high-quality protein with the right ratio of essential amino acids (EAA) is key. However, these nutrients need to be digested to be available and effective for your muscle cells.

Protein availability is measured by three values:

  • Chemical Index: Protein capacity to provide to the body all the amino acids in the right proportions to support good body functions.
  • Digestibility: Proportion of protein available for the body after digestion; it takes into consideration what is rejected (waste – protein not being used by the body).
  • PDCAAS: Indicator of the available ideal amino acid profile that can be used by the body. Calculated by multiplying the Chemical Index by Digestibility.

The higher the protein source’s protein availability, the more protein your body will utilize. This means the quantity of protein your body can digest is more important than the number of grams on a product label.

In a study of these indexes, NWP exceeded traditional whey protein isolate in every category, meaning it has more of what your body uses and less of what it can’t process.

While plant-based protein was not part of the study, research indicates that Pea protein has a PDCAAS of 90 and rice protein has a PDCAAS of 41.

Protein Purity

In the same way that protein availability affects the amount the body can process, protein purity affects how effectively the body can utilize it.

A small serving at a high purity level can provide the same benefits as a large serving at a lower purity level.

For example, NWP has a higher purity level of 95% on a dry basis and superior bioavailability. Studies have shown that 15g of NWP activates the same level of muscle protein synthesis as 30g of other proteins. That means consumers can achieve equal or better protein synthesis with half the serving size.

In other words, you can eat less protein and achieve the same results.

This represents a fundamental shift in the way customers think about consuming protein. While traditional protein sources rely on quantity and price, NWP moves the focus to quality and effectiveness.

Processing Method

While protein quality is often associated with the nutrition of the end product, the differences actually begin with the raw ingredients and how they are processed.

The processing methods used to manufacture protein ingredients have a significant impact on the quality of the protein. Let’s examine how the three main types of supplemental protein are made.

Traditional Whey Protein Manufacturing

Traditional whey protein is the most common ingredient in protein powders because of its good amino acid profile. It is produced as a byproduct of cheese manufacturing and undergoes extensive processing, including:

  1. Multi-site Heat Treatments
  2. Chemical Reactions
  3. Enzymatic Reactions
  4. Filtrations
  5. Drying

This heavy processing alters the quality and chemistry of the protein. The result is a powder containing protein, but one likely to contain production residues, sugar, fats, bacteria and a slew of hard-to-pronounce chemicals. This alters its original form and nutritional benefits.

Manufacturing processes like these also raise concerns for consumer health

Extensive processing can make traditional whey protein more difficult to digest. Consumers of whey protein frequently report side effects such as bloating, gas and stomach cramps. And studies have shown high consumption of processed whey can cause digestive distress, nausea, loss of appetite, acne, headaches and fatigue.

Despite strong nutritional benefits, years of science and longstanding popularity in the supplements market, consumers have raised concerns about the above health findings around traditional whey. Personal beliefs and lifestyle choices like vegetarianism and veganism are also pushing consumers to reconsider protein sources. This has led many to turn to alternatives like plant-based powders and NWP.

Plant-Based Protein Manufacturing

The first place many consumers turn when looking for an alternative protein is of the plant-based variety. The assumption here is that these proteins are more natural and less processed because they come from plants. But the truth is more complicated.

Extracting protein from plants in a solid state is extremely difficult. As a result, isolated plant proteins are heavily-processed with heat treatment and chemical agents.

While it’s not the case for all plant proteins, some distributors confirm that the processing of plant protein is not always local. Plants are grown in the US but then shipped to China. There, the protein is extracted with solvents that aren’t approved for use in the US, and then shipped back to the states for powder manufacturing.

Regardless of where the protein is manufactured, the process is intense. The extraction of plant proteins can introduce chemical and processing residue that damages protein quality.

NWP Manufacturing

Compared to traditional whey and plant proteins, NWP manufacturing is far more minimal. Case in point, whereas traditional whey protein processing requires multiple steps, native whey requires only three:

  1. Milk preparation pasteurization
  2. Cold membrane filtration
  3. Drying

The process is extremely gentle, using only cold filtration from milk and drying. And some manufacturers will even go a step further by only using milk sourced from farms near the manufacturing plant.

Regardless, the result is a cleaner whey protein with no added chemicals, and derived from a single ingredient: milk. This minimal processing preserves the quality of the protein and its nutritional benefits.


As the data above makes clear, the quality of a protein source is of equal or greater importance to the quantity of protein consumed. And as cleaner, higher quality protein sources become readily available, consumers and manufacturers alike are starting to take notice.