Section Menu

Proteins: Are They All Equal?

Are all proteins equal? Curious about how proteins are scored? Our recent update compares scoring methods that study how the body absorbs amino acids. Check out that blog here: PDCAAS to DIAAS: A new way to look at protein quality.

Agropur Ingredients believes in investing time and attention into up & coming industry members. Through our internship program, we give students hands-on experience and knowledge that will help guide them into a successful career. Ultimately we hope our investment serves as an avenue to create a food industry that continues to improve year after year. For more information on available internship opportunities please contact

Content by Josh Garsow, Viterbo University Dietetics Student. Some additions made by Aaron Martin, Nutrition Innovation Manager.

Protein is now an established trend. As with many established trends, sensationalism overshadows actual education on the health trend, making it difficult for consumers to interpret the value of the product and decipher which label claims are important to them. Educating your customers on the basics can help consumers make quality-based decisions and will help them differentiate your product from other health and wellness products.  Consider the following an example of basic protein education.

What are Amino Acids?

Amino acids are the building blocks that make up a protein. Various amino acid scoring methods (PDCAAS, DIAAS) help determine protein equality. There are essential amino acids and nonessential amino acids. Non-essential amino acids can be synthesized by the human body. Essential amino acids must be obtained through diet.  It is from these 9 essential amino acids we can categorize complete and incomplete proteins.

Complete vs. Incomplete Proteins

Complete proteins include foods that contain all 9 essential amino acids in sufficient amount. Complete or high biological value proteins are typically animal-derived foods and some plant-based foods, such as dairy products, eggs, fish, meats, soy, quinoa, buckwheat and chia seeds.

Incomplete proteins include foods that do not contain all the essential amino acids or a sufficient amount of them for the body. Foods that are incomplete proteins include nuts and seeds, legumes, grains, and vegetables. Incomplete proteins are not inferior to complete proteins but need to be paired with another protein source to contain sufficient amounts of essential amino acids.  These pairings are known as complementary proteins. Some examples of said pairings include rice and beans, spinach salad with nuts and seeds, peanut butter with whole-grain bread and many more.

Not all Protein is Equal

There are many other differences between proteins beyond essential amino acids. Protein sources react differently in the body based on unique absorption rates and differing levels of both essential and non-essential amino acids.

The unique amino acid composition of proteins affects how the body is able to utilize them for growth, recovery & maintenance. The absorption rate will affect how quickly the amino acids are broken down and available to be used in the body.  To get the most out of the protein ingested-look for a higher ratio and amount of essential amino acids compared to non-essential amino acids. Essential amino acids provide a more favorable rate of protein synthesis and recovery.

One study stated milk protein was more effective in muscle repair following exercise compared to soy protein. In a long-term study, milk protein promoted more lean muscle mass growth over the 12 weeks of resistance training compared to soy protein. Milk is more effective for promoting lean muscle growth because of whey and casein proteins.   Compared to soy, whey and casein contain a greater ratio of essential amino acids and are metabolized more effectively in human tissue for growth and repair.  Whey protein promotes a rapid rise of amino acids whereas casein delivers a “slow and steady” level of amino acids in the bloodstream. The result is both fast and slower-acting protein – a perfect punch for switching on muscle growth.

Don’t dismiss plant proteins yet.  Milk proteins are heavily researched and proven effective – however, pea protein has been the focus of some promising muscle building and recovery research as well.  A study in 2015 published in the Journal of the International Society of Sports Nutrition concluded both Pea and Whey protein obtained similar recovery benefits in young, healthy males.  Pea protein can offer a hypoallergenic product from plants – free of any allergen-containing items. Pea protein is also high in critical branched chained amino acids; although not as high compared to whey, an increased level of branched chained amino acid initiates the muscle recovery and building process (more on this below).  Plant-based options can be an effective and suitable protein source for those wishing to stick to plant nutrition.

Protein Quality & Quantity

More is not always better when it comes to protein. There are many circumstances that the body needs can be met with lower amounts compared to higher dosages. For instance, a person that finished resistance training would need more protein for muscle repair compared to someone that is sedentary during the day. Beyond quantity, timing is also a factor.  Daily protein needs should not be met in one sitting but instead be consumed throughout the day.

Benefits of Essential Amino Acids on Muscle Building

Not all protein sources have the equivalent amount of essential amino acids. As research shows, foods with complete proteins stimulate muscle protein synthesis better than incomplete proteins. There are a group of amino acids known as BCAA’s (branch chain amino acids) which consist of leucine, isoleucine, and valine. These 3 amino acids make up about 35% of all muscle tissue and are critical to stimulate protein synthesis and inhibit the breakdown of muscle cells.

One essential amino acid, Leucine, has been shown to be the key activator of muscle protein synthesis in both exercising or sedentary individuals. It has been shown that proteins rich in leucine that is digested rapidly would be the most beneficial to stimulate the building of skeletal muscle.  That being said, foods high in leucine, along with containing all nine essential amino acids, are the best for muscle growth.

For instance, eating 1 cup of cottage cheese has 2.9g of leucine and all 9 essential amino acids compared to black beans with 1.2g leucine; 1.2g is still is high but black beans don’t have all the essential amino acids.  Without a complementary pairing, the black beans won’t stimulate anabolism as effectively. Some other foods that are high in leucine include whey protein isolate, skinless chicken breast, tofu, canned tuna, skim milk, peanut butter, and quinoa.


  • Animal-derived proteins such as dairy and meats offer more bang for the money because of higher amounts of essential amino acids compared to soy, pea and rice are needed at higher amounts, but they do have other benefits.
  • If choosing to ingest vegan proteins (non-animal) make sure to eat a variety of sources in sufficient amounts to obtain enough essential amino acids to stimulate maximum recovery and growth.  This might be 25g -30 g of pea protein or other plant-based source opposed to 20 g of whey protein isolate.
  • Exercising individuals have increased protein needs, the best sources are complete proteins and contain all BCAA’s from whole foods such as dairy, eggs, red meat, chicken, fish, and whey protein.
  • More is not always better! Distribute protein intake evenly throughout the day by including meals and snacks with high-quality protein.
  • Combine sources of proteins to provide a balance amount of amino acids and allow for longer anabolic response of protein throughout the day. Examples of which are Whey + Pea protein, Whey + Casein, Pea, Egg & Whey, and many others.



Learn more about TJ’s internship and journey at Agropur during the summer of 2020.


Learn more about Claire’s internship and journey at Agropur during the summer of 2020.