Whey Protein vs Plant Protein

Whey protein is generally considered the gold standard for muscle growth due to its ideal amino acid profile and rapid absorption. But with more people following plant-based diets, vegan protein powders are gaining popularity. This article compares whey protein vs plant protein to help you make an informed decision about which option may be best for you!

General comparison: whey protein vs plant protein

Macronutrient comparison

This table shows the macronutrient comparison of whey and plant protein powders per 30-gram serving:

Protein PowderCaloriesProteinFatCarbs
Whey protein concentrate110-12025-30 grams0-2 grams1-5 grams
(0-3.5 grams of lactose)
Brown rice protein12025 grams0.5 gram4 grams
(1 gram of fiber)
Pea protein12027 grams0.5 gram2 grams
(0 grams of fiber)
Soy protein isolate12025 grams1.5 grams1.5 grams
(0 grams of fiber)
Hemp protein12012 grams2 grams13 grams
(11 grams of fiber)

Other comparison factors

This table shows other factors we have considered in our comparison. We explain more in-depth below.

WheyBrown RicePeaSoyHemp
EAAsAdequate in all 9 EAAsLow in lysineLow in methionineAdequate in all 9 EAAsLow in lysine & leucine
Protein serving for 3 grams of leucine28-29 grams38-41 grams37-42 grams38-44 grams60-75 grams
Rate of digestionFastMediumMediumMediumMedium
BioavailabilityHighLowMediumHighLow
Allergy & intolerance considerationsMilk; may contain a small amount of lactoseFree of common allergensFree of common allergensSoyFree of common allergens
Calories per 25 grams of protein110-120110-120110-120110-120250
Cost per 25 grams of protein$1.00-$2.00< $1.00< $1.00< $1.00> $2.00
Taste & textureNeutral flavor; mixes well with a smooth texture; may have more additives or artificial ingredientsMay have an earthy, grassy, or nutty taste; more; may have a chalky or gritty textureMay have an earthy, grassy, or nutty taste; more; may have a chalky or gritty textureMay have an earthy, grassy, or nutty taste; more; may have a chalky or gritty textureMay have an earthy, grassy, or nutty taste; more; may have a chalky or gritty texture

How they’re made: whey & plant-based protein powders

Whey protein powder

Whey is a type of protein present in milk. Whey is separated from the curd during the cheese-making process. It is heated, microfiltered, pasteurized, and dried to make whey protein powder (1, 2).

Whey protein powder has varying levels of processing and filtering to create the following varieties: whey protein hydrolysate, whey protein isolate, and whey protein concentrate.

The amount of processing affects the calories, protein, fat, and carbohydrates (including lactose) as seen in the table below (3). Nutrition facts are per 30-gram serving:

Whey Protein TypeCaloriesProteinFatCarbs
Hydrolysate11030 grams0 grams1 gram
(0-0.5 gram of lactose)
Isolate11028 grams1 gram2 grams
(0-1 gram of lactose)
Concentrate12025 grams2 grams3-5 grams
(2-3.5 grams of lactose)

Plant protein powder

Brown rice protein powder is made by grinding rice grains and adding an enzyme to help separate the starch from the protein (4).

Pea protein powder is made from golden or yellow split peas. The process involves mechanically removing the outer shells and grinding the dry peas into a fine powder (5).

Soy protein powder is made from soybean meal that remains after the soybeans have been dehulled and defatted. The soybean meal is soaked in water, acid, or alcohol to remove the sugar and fiber so that only the protein portion is left (6).

Hemp protein powder is made by dehulling the outer shells and pressing the hemp hearts to remove the fat. The remaining product is then ground into a fine powder (7).

Despite each processing type leaving mostly protein in the final product, plant protein powders can vary in protein, fat, and carbohydrates as shown in the table below. Nutrition facts are per 30-gram serving:

Plant Protein TypeCaloriesProteinFatCarbs
Brown Rice12025 grams0.5 gram4 grams
(1 gram of fiber)
Pea12027 grams0.5 gram2 grams
(0 grams of fiber)
Soy12025 grams1.5 grams1.5 grams
(0 grams of fiber)
Hemp12012 grams2 grams13 grams
(11 grams of fiber)

Protein & amino acids

Most protein powders have a similar amount of protein per serving but vary in their amino acid profile.

For optimal muscle growth and repair, it’s important to choose a protein powder that is a complete protein which means it contains all nine essential amino acids (EAAs) in adequate amounts. Of the essential amino acids, leucine is the most important for muscle growth.

Leucine is heavily involved in muscle protein synthesis (MPS), and 3-4 grams are needed for maximal MPS after strength training. This equates to around 30 grams of protein, though it varies depending on the protein source due to the varying amount of leucine.

Here is a breakdown of the essential amino acid content in whey and common plant protein powders, along with the amount of protein needed to get 3-4 grams of leucine (4, 8):

Protein TypeContain all EAAs in adequate amounts?Amount of protein for 3 grams of leucineAmount of protein for 4 grams of leucine
WheyYes28-29 grams37-38 grams
Brown riceNo, low in lysine38-41 grams50-55 grams
PeaNo, low in methionine37-42 grams49-56 grams
SoyYes38-44 grams51-59 grams
HempNo, low in lysine & leucine60-75 grams80-100 grams

Digestion & bioavailability

There are a couple of things to consider when reviewing the digestion of whey protein vs plant protein powders. First is the rate of digestion or the time it takes the body to break it down into molecules it can absorb. The second includes factors that may decrease protein utilization.

Rate of digestion

Whey protein is fast-digesting while plant protein is considered medium-digesting as noted below (egg white and casein protein are included for comparison):

  • Fast-digesting: (8-10 g/hr): whey hydrolysate/isolate/concentrate
  • Medium-digesting (4-7 g/hr): egg white, brown rice, pea, soy, hemp
  • Slow-digesting (3 g/hr): micellar casein

Fiber and fat can impact the rate of digestion. The processing of plant-based protein powder removes most of the starch, fiber, and fat, though some types, like hemp, may still have a small amount of fiber and fat since it is less processed. Whey protein doesn’t contain fiber or starch but may contain fat.

Bioavailability of protein

Bioavailability is the ability of your body to digest, absorb, and use nutrients from food. Since most plant proteins are low in one or more essential amino acids, their bioavailability is lower than whey.

The protein digestibility-corrected amino acid score (PDCAAS) is a method used to compare how well a particular food meets the amino acid requirements for humans and the digestibility of the protein in it.

The digestible indispensable amino acid score (DIAAS) is another method for measuring protein digestibility. It is considered more accurate than PDCAAs because it measures the amino acids that make it to the ileum, which is the last portion of the small intestine. Amino acids that don’t make it to the ileum are assumed not to be adequately digested and therefore unusable by the body (9, 10).

The table below compares the PDCAAs and DIAAS of whey protein vs plant protein:

Protein TypePDCAAS (0.00 to 1.00)DIAAS (0 to > 100)
Whey isolate1.00109
Whey concentrate1.0085-97
Soy isolate0.9890-91
Pea0.8970-82
Rice0.4237-47
Hemp0.6354

Allergies & intolerances

Milk allergy

Whey protein is not safe for people with a milk allergy.

Lactose intolerance

Some people don’t make enough of the enzyme lactase needed to digest lactose, a sugar found in milk. As a result, they may experience bloating, gas, and general stomach discomfort. Most whey protein is low in lactose, especially isolate and hydrolysate forms, so people with lactose intolerance may tolerate it just fine.

Research shows that around 12 grams of lactose can be consumed in one sitting or up to 24 grams throughout the day without experiencing symptoms (11, 12).

For reference, here is the amount of lactose per 30-gram serving in whey protein powder:

  • Whey concentrate: up to 3.5 grams
  • Whey isolate: 1-3 grams
  • Whey hydrolysate: 0-0.5 grams

Soy, nut, peanut, sesame, & wheat allergies

Some plant protein powders are free of common allergens, including pea, rice, hemp, quinoa, and most seed proteins.

Soy, tree nuts, and peanuts are common allergens that may be found in plant protein powders. Sesame seeds and wheat are other allergens that may be cross-contaminated, so always read the nutrition facts label.

Taste & texture of whey protein vs plant protein

Most people prefer the texture and taste of whey protein compared to plant protein.

Whey protein tends to have a smooth texture and a neutral flavor.

Plant protein can have a grainy texture and an earthy, grassy, nutty, or bitter flavor. Sometimes an emulsifier, like sunflower or soy lecithin, is added to help the powder dissolve and blend more easily which can help create a smoother texture.

Both whey and plant protein powders are available in flavored varieties which may help the palatability. If you avoid certain sweeteners, gums, thickeners, or artificial ingredients, check the ingredients label first.

You can also experiment with adding protein powder to different foods or blending it with various liquids to achieve your preferred taste and texture.

Cost of whey protein vs plant protein

The cost of protein powders may vary based on the source, level of processing, filler ingredients, and specialized qualities or certifications like organic, gluten-free, grass-fed, keto, paleo, etc.

Generally, most protein powders cost around $0.75-$1.75 per 30-gram serving. That comes out to around $11.35-$26.50 per pound.

If the cost per gram of protein is important to you, we have sorted the cost per 25 grams of protein below:

  • < $1.00: soy isolate, pea, brown rice
  • $1.00-$2.00: whey hydrolysate, whey isolate, whey concentrate, brown rice & pea blend
  • > $2.00: goat whey concentrate, hemp

Who can benefit from protein powder?

Protein powder is most beneficial for people with higher protein needs or who generally have difficulty eating enough protein daily.

The optimal protein intake for most people is 1-1.2 g/kg body weight per day, while those engaging in increased physical activity or who otherwise have higher protein needs benefit from 1.4-2.2 g/kg body weight per day to promote the maintenance of lean body mass, muscle growth, performance improvement, and improved body composition (13, 14, 15).

Overall, protein powder is a convenient way to consume protein, especially for active people who want to easily time their protein intake around their workouts for optimal muscle building.

Best protein powder for muscle growth

Whey protein, soy protein, and a blend of brown rice protein + pea protein are considered the best options for those focusing on building muscle, maintaining muscle, and preventing muscle loss since they contain adequate amounts of the essential amino acids, including leucine.

If you want to narrow it down to the top protein source for muscle growth, whey protein is frequently shown to promote greater MPS than other protein sources, so it’s the best choice for those who tolerate it (16).

Best protein powder for weight loss

Protein needs for weight loss

To lose weight you must consume fewer calories than you expend between your body’s maintenance activities, like breathing, digesting, and repairing, and the calories you burn from being physically active. 

When you eat fewer calories, you are at greater risk of losing muscle mass, so your protein intake becomes more important than usual.

To maintain your muscle when you are eating in a calorie deficit, there are recommendations for eating around 2.2 g/kg body weight of protein per day, though your individual needs may range from 1.6-2.8 g/kg (17).

The protein powders with the fewest calories per gram of protein are whey, brown rice, pea, and soy.

Whey, brown rice, pea, and soy protein powder contain around 110-120 calories per 25 grams of protein. Hemp protein powder contains around 250 calories per 25 grams of protein.

Final thoughts

While whey protein and plant protein can provide similar benefits for muscle building and help you meet your protein needs, there are differences in protein content, calories, rate of digestion, allergens, cost, taste, and texture that you’ll want to consider.

Considering all factors, our overall pick is whey protein, if tolerated, followed by brown rice and pea protein blend and soy protein. We hope this article helps you choose the best option to meet your needs!

Comparison of whey protein vs plant protein, including digestion, micronutrients, protein profile (EAAs & BCAAs), muscle building ability & cost.

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Photo of Collette Sinnott, RD, LD

Collette is a registered dietitian and has over a decade of experience working with athletes, children & adults on tube feeding, and people with chronic health conditions. She has been writing about food and nutrition since she was in high school and has a passion for sharing evidence-based information, especially on the topics of protein and the importance of maintaining muscle mass for healthy aging.

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