Vegan Protein vs Whey: What’s Better for the Older Adult? 

Vegan Protein vs Whey: What’s Better for the Older Adult? 

“Vegan Protein vs Whey: What’s Better for the Older Adult?” was written by Daria Zajac, RDN & edited/reviewed by Aly Bouzek, MS, RDN. 

Protein is a popular topic within the older adult population because protein plays a vital role in the body as we age. You may have even heard of different types of protein including vegan protein and whey protein.

But have you ever wondered the real differences between them? If so, this is the article for you because we are about to dive into the details of all things protein

Protein 101 

Protein is made up of amino acids, the building blocks of protein. Amino acids all work together in different combinations to help our body function.


Some of protein’s main roles include:

  • Wound healing
  • Building and preserving muscle
  • Maintaining fluid balance 
  • Immune support

This is not an exhaustive list by any means, but it just shows that protein has a role in every part of our body.

There are 20 different amino acids.

However, only 9 of these amino acids are considered “essential.” This means that our bodies cannot produce them naturally, and instead we must get them from our food!

With all that being said, protein is such an important nutrient that should not be overlooked in anyone’s diet.

Older Adults and Protein Intake 

Since protein plays such a large role in our health, you may be wondering how much protein you need every day.

The answer really depends on the person.

Typically, a healthy adult would need between 0.8 – 1 grams of protein per every kilogram (kg)* of body weight. For example, a healthy 65-year-old male who weighs 175 pounds (79.5 kg), would need approximately 64 – 80 grams of protein per day.

Here’s the math if you’d like to follow along: 

0.8 grams x 79.5 kg = 63.6 grams (we rounded up to 64)

1 gram x 79.5 kg = 79.5 grams (we rounded up to 80)

Again, this individual would need 64 – 80 grams of protein per day. 

*Note: 1kg=2.2lbs

The general recommendation is 0.8 – 1 grams per kg of body weight, but newer research is suggesting that older adults need closer to 1 – 1.2 g of protein per kg of bodyweight. (1

If we were to follow these protein recommendations, then our above individual would instead need 80 – 95 grams of protein per day. 

There are also times when a person needs more or less protein in their diet due to a medical condition or disease progression. If you are interested in learning more, then head over to our article on Protein Requirements for Older Adults.  

Complete Protein vs Incomplete Protein

Meats, poultry, fish, dairy, and legumes are protein-rich food sources. Keep in mind, though, that not every protein source is created equally.

Animal sources of protein are considered complete protein sources because they have all 9 essential amino acids. Meat, poultry, fish, and dairy products are all considered complete.

On the other hand, if one or more of these 9 essential amino acids is missing, then the protein source is incomplete. Vegan (also known as plant-based) sources are usually incomplete protein sources.

Plant sources such as legumes, nuts, and seeds are typically incomplete.

There are some exceptions though. Quinoa, soy, hemp, buckwheat, and peas contain all 9 essential amino acids even though they are vegan sources of protein.


Bioavailability is how efficient our food is when it’s inside our bodies. Different foods have different uses for our bodies, and bioavailability helps  us determine which foods give us the “biggest bang for our buck.” 

In other words, when foods are consumed, how much of their nutrients can be used efficiently by our bodies. 

How Do We Measure Protein Bioavailability?

The Protein Digestibility Corrected Amino Acid Score (PDCAAS) is used to measure protein bioavailability.

The PDCASS considers the first limiting essential amino acid makeup of a food and then measures the number of amino acids that don’t get absorbed by the body/are excreted. (2)

When a food is assigned a PDCAAS score of 1, the food contains all 9 essential amino acids and is considered a high-quality protein.

Scores less than 1 mean that the protein source doesn’t have enough of one or more of the 9 essential amino acids and is a lower-quality protein. 

What is Vegan Protein?

Vegan protein is protein that comes from plant-based sources such as soy, peas, etc. This type of protein is most suitable for those that are lactose intolerant, have a dairy allergy, or simply want to follow a plant-based diet.

Vegan protein is absolutely a great alternative for those individuals mentioned, but we must acknowledge that plant sources of protein have a lower bioavailability compared to animal sources. 

Low bioavailability means that the protein in the plant-sources doesn’t get absorbed well, and we don’t get as much protein from that food compared to if we were eating animal-based protein. (3)

Types of Vegan Protein 

Let’s take a deeper look into common complete sources of vegan protein.

Vegan Protein


Soy is a versatile vegan protein source. Many people are turning to soy-based products because they are most comparable to animal protein sources, easy to cook, and can be easily made into other products!

Tofu, tempeh, miso, and soy sauce are products made from soybeans that you may already enjoy!

In addition to protein, soybeans also contain fiber, iron, calcium, and zinc making them a great nutrient-dense alternative for whey sources of protein. 


Peas have also gained popularity in the last few years, and rightfully so! 

They contain a variety of nutrients including fiber, potassium, iron, and vitamin C which can make it a great addition to your diet (whether you follow a vegan diet or not!).

Additionally, pea’s protein PDCAAS score is 0.64 – 0.93 because of its bioavailability and differences in extraction and filtering process between studies and products used. (3,4

Peas have also gotten so popular due to the fact that they can be isolated into a powder form that provides people with an alternative way of increasing their protein intake. Pea protein powder is a common plant-based protein choice. 

Hemp Seeds

Last, but not least, the hemp plant contains seeds that are commonly consumed for their nutrients, but they are also utilized to produce: 

  • hemp oil
  • hemp pasta
  • hemp milk
  • hemp protein powder

The hemp seeds themselves can be eaten raw, cooked, or roasted. 

Hemp seeds are very high in omega-3 fatty acids, which our bodies cannot make on their own. Dietary intake of omega 3’s is essential to help combat health issues like high blood pressure and high cholesterol. 

So, not only do hemp seeds provide protein and omega-3 fatty acids, but they also provide fiber, iron, potassium, and magnesium – making them a great addition to any smoothie or salad.  

All About Whey Protein 

Let’s switch gears now, from vegan protein to whey protein. What is whey protein?

Whey Protein

Ever wonder what the liquid portion of your yogurt is? That’s whey! 

Whey protein is found naturally in dairy products like milk, cheese, yogurt, and cottage cheese.

It’s considered an animal-based source of protein and is not typically suited for those with dairy allergies or those following a strict vegan diet.

Whey is a complete protein and has a PDCAAS score of 1.  

How is Whey Protein Extracted?

The extraction process of whey is quite complex. But put simply: whey is extracted using heat and specific enzymes during the cheese-making process, and then dried to form a powder for you to enjoy.

Many consumers have turned to whey protein powder to meet their daily protein intake since it is easily digested and utilized by the body. It can simply be added to water or milk to make a protein shake on-the-go. 


Milk provides calcium, protein, potassium, phosphorus, vitamin B12 and fortified vitamin A and D. Providing at least 8 grams of protein per cup, milk contains all important nutrients for the older adult. 

You can add it as a base into smoothies, shakes, cereal, and even into your morning coffee to boost your protein intake.


Made through fermenting milk, yogurt provides the nutrients that it contains from milk, but it’s also a probiotic!

Probiotics are proving to have a huge impact on our digestive system because they help to maintain a healthy gut by fighting off bad bacteria and help us digest our foods.  

Yogurt can be eaten in so many ways:

  • plain
  • added to smoothies
  • acai bowls
  • oatmeal
  • even desserts!

It’s so versatile, you really cannot go wrong!

Vegan Protein vs Whey: What’s Better for the Older Adult?

There are a few things to keep in mind when we talk about vegan protein vs whey protein.  

Individual preference is ultimately the most important factor. This is because if you don’t like eating a certain food, then you probably won’t be eating it! The protein from the food won’t make it into your body, so it’s a good idea to choose foods you like. 

Let’s look at the science of vegan protein vs whey protein.

Vegan Protein vs Whey Research

Vegan Protein vs Whey for Muscle Building

A literature review of studies done on vegan vs whey protein over the last decade emphasizes that whey protein is more easily digested than vegan protein and is readily available to use after absorption compared to vegan sources of protein. (4)

Since whey protein is available for our body to digest and use faster than vegan protein, it can stimulate muscle building quicker than vegan protein sources. 

Volek et al. conducted a study where supplementing with vegan vs whey protein was tested on the effect of lean body mass.

Their results found that whey protein and resistance training combined, ultimately led to increased muscle gain compared to soy (vegan) supplementation. (5)

However, other studies within the literature review concluded that vegan vs whey protein supplementation may not matter at protein intake greater than 30 grams. (4)

Why We Need More Research on Vegan Protein vs Whey

Much of the research that exists on vegan vs whey protein is on younger adults and the male population. The results cannot be generalized to the older adult population (65 years+), so we need more research on this topic as it relates to older adults. 

Also, most of the research is on vegan vs whey protein powders and not necessarily studying the effects of whole-food protein sources.

One specific article within the literature review mentions that since there are such large differences in the amino acid compositions of vegan vs whey protein sources, it’s hard to conclude of any one source being better than the other. (6)

Vegan Protein vs Whey: Conclusion

So, while there is no clear answer as to whether one protein source is better, there are a few key points to remember when it comes to vegan vs whey protein:

  • Eat food you enjoy 
  • Have a variety of protein sources in your diet
  • No one food will give you all the nutrients your body needs
  • If you aren’t meeting your protein needs through food, consider experimenting with vegan or whey protein powder
  • Consult your doctor and registered dietitian before making any changes to your diet


  1. Bauer J, Biolo G, Cederholm T, et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE study group. J Am Med Dir Assoc. 2013;14(8):542-59. doi: 10.1016/j.jamda.2013.05.021.  
  2. Schaafsma G. The protein digestibility-corrected amino acid score. J Nutr. 2000;130(7):1865S-7S. doi: 10.1093/jn/130.7.1865S.   
  3. Berrazaga I, Micard V, Gueugneau M, Walrand S. The role of the anabolic properties of plant- versus animal-based protein sources in supporting muscle mass maintenance: a critical review. Nutrients. 2019;11(8):1825. doi: 10.3390/nu11081825.  
  4. Putra C, Konow N, Gate M, York CG, Mangano KM. Protein source and muscle health in older adults: a literature review. Nutrients. 2021;13(3):743. doi: 10.3390/nu13030743
  5. Volek JS, Volk BM, Gómez AL, et al. Whey protein supplementation during resistance training augments lean body mass. J Am Coll Nutr. 2013;32(2):122-35. doi: 10.1080/07315724.2013.793580. 
  6. Gorissen SHM, Crombag JJR, Senden JMG, et al. Protein content and amino acid composition of commercially available plant-based protein isolates. Amino Acids. 2018;50(12):1685-1695. doi: 10.1007/s00726-018-2640-5. 

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