Pea Protein vs. Whey for Weight Loss & Body Composition

Let’s take a look at pea protein vs. whey, how they are both made, what they have in common, and how you can use these supplements to aid in weight loss. 

How is Pea Protein Powder Made? 

In order to make pea protein, dried peas are ground into a flour, mixed with water, and then most of the fat, fiber, and starch is removed. The powder that remains is what we know as the supplement of pea protein isolate.

So, if you’re considering buying pea protein, make sure it says “pea protein isolate” on the ingredients list to ensure you’re actually getting pea protein and not just powdered peas and fillers. 

How is Whey Protein Powder Made? 

Ever heard of little miss muffet who was eating her curds and whey? Well, when you add acid to milk, which is something you have to do to make cheese, it curdles and separates. The solid portions are called the curds and the liquid is the whey. 

The liquid actually used to be discarded after the curds were extracted to make cheese, but scientists eventually discovered that liquid could be dried into a powder to produce a substance packed with high quality, highly absorbable protein. That’s how whey protein powder was born. 

So, how do these two compare? Pea protein and whey protein powder are actually much more similar than you would think, but they both come with their own set of benefits and downsides. 

Whey Protein 101

Whey is the most popular protein powder supplement on the market and for good reason. It’s cheap, versatile, tastes great, is highly absorbable and has one of the highest contents of muscle-building amino acids of any other food. According to science, it’s one of the most effective forms of post workout nutrition for recovery and altering body composition.

Whey protein is available in three forms: isolate, concentrate, and hydrolysate. The most common forms available being isolate and concentrate. So let’s take a closer look at whey isolate vs. concentrate.

Whey Isolate

Whey isolate is the most popular form of whey on the market and is more processed in order to remove most of the fat and lactose. Thus, it can be 90-96% protein per serving and is much more friendly to those who do not do well with lactose. Without all of the extra ingredients and filler, this makes whey isolate more absorbable as well. 

Whey hydrolysate removes virtually all ingredients of whey except the protein and is even predigested for the consumer making it extremely easy to digest. However, given this extensive processing, it can be very expensive. 

Whey Concentrate

The cheapest form of whey protein to manufacture is the whey concentrate, which contains more fat and lactose than whey isolate. The problem with whey concentrate is that the actual protein content varies widely, from 35% protein to 80% protein per serving. The rest is usually a cheap filler like maltodextrin. 

So, if you’re getting your whey concentrate for a bargain, it’s likely on the lower end of the aforementioned protein range, so be sure to check your labels. Those with lactose intolerance also tend to have tummy problems when they consume whey protein concentrate. 

Pea Protein 101

With more and more consumers exploring plant-based alternatives, pea protein has slowly grown in popularity and demand recently. While hemp, rice, and soy are other plant-based proteins out there, pea is slightly better than all of these when compared to the highly popular whey protein.

It is pretty high in iron and contains more micronutrients compared to most other plant-based protein powders. It also has an impressive profile of amino acids when compared to similar products from different sources. 

What are Amino Acids and Why Are They Important for Body Composition?

Different types of amino acids in a Venn diagram: Essential amino acids, Non-essential amino acids, Conditionally essential amino acids, and Branched chain amino acids (BCAAs)

Protein sources that contain all 9 essential amino acids, meaning amino acids the body can’t make itself and thus must get from food, are referred to as complete proteins. If any protein source lacks all 9, it is called an incomplete protein. Most animal protein sources are complete; however, a common question is whether pea protein (or similar plant-based protein powders) is also complete.

This is an especially pressing question when asked by active individuals because the content of branched chain amino acids (or BCAAs) is important. That’s because those are the amino acids that are not only essential, but are the most responsible for muscle growth and body composition changes. So, when looking at pea protein vs. whey, how do their amino acid profiles differ?

Pea Protein Amino Acid Profile

Pea vs. whey graph showing different type and amount of amino acids and protein quality

About 85% of pea protein powder is protein, and it is a good source of all branched chain and essential amino acids, with the exception of one: methionine. However, since pea protein powder is high in the same satiating, muscle-building amino acids as whey, research shows that it can be as effective as whey at building muscle. This makes pea protein one of the best plant-based protein powders out there. 

Whey Protein Amino Acid Profile

A whey protein isolate contains 90% protein by weight, making it the purest protein available. Remember, pea protein is about 85% protein, so they aren’t too different in that regard. 

Approximately 60% of the amino acids found in whey protein are essential chain amino acids. The amino acid that is of particular interest is leucine, which is a branched, essential chain amino acid that is uniquely identified for its ability to stimulate muscle growth. Whey protein is about 11% leucine, which is quite high. You may be surprised to know, however, that pea protein is about 9% leucine, which makes both sources comparable in their ability to grow muscles. 

Pea Protein Pros and Cons

Pros

Great for Vegans and Milk-Sensitive Individuals 

If you are someone who does not consume animal products, but still wants a protein supplement that gives you the amino acids you need, pea protein powder is a great option. As an additional benefit, it is an excellent alternative to milk if you are someone who cannot tolerate milk or dairy products well.

Does pea protein cause gas? This is something you may be wondering. The answer is no. In order to manufacture pea protein, most of the elements of the peas are removed, including the soluble fiber that causes that dreaded legume gas.

Affordable

Most plant-based versions of animal-based protein supplements like whey protein tend to be more expensive for sourcing reasons. However, you’ll be happy to know that pea protein is comparably priced to whey protein powder. 

Cons

Acquired Taste

What can a ground powder of peas possibly taste like? If some of you are thinking “not very good” then you’re not alone. True, you can definitely taste the peas when consuming the powder by itself which is something that may take getting used to for some. To help with this, you can blend your pea protein in smoothies or combine it with other protein. 

Low in Methionine

Methionine is one of the essential amino acids and, although pea protein has some small amounts of it, the amount is low when compared to whey. However, if you’re a meat-eater who just doesn’t do dairy, you should have no problem getting enough methionine from animal products.

Alternatively, if you are a vegan or vegetarian, you might want to combine your pea protein powder with rice protein. Although rice protein doesn’t have nearly the impressive amount of essential amino acids that pea does, it is notoriously high in methionine. In fact, the mixture of pea and rice protein powder has an amino acid profile so similar to whey, it’s called in the fitness world “the vegan’s whey.” The combination is also more palatable than the pea protein by itself. 

Whey Protein Pros and Cons

Pros

Control Hunger

The hormone ghrelin, which produces hunger and tells your brain you are full, has been shown to be reduced by drinking whey protein. This makes whey protein the perfect tool for fighting cravings and overeating, especially when you consider that it’s shelf-stable, portable and quick to prepare. 

Heart Healthy

A study conducted by Iowa State University showed that young adults with hypertension could lower their blood pressure by adding whey protein shakes to their diets. Another study showed that drinking whey protein could lower triglycerides and raise your good cholesterol, when consumed regularly. 

Absorbs Quickly

Whey is particularly effective when eaten after training, due to its rapid digestion

Cons

Not Suitable for Dairy Allergies

Even though most of the lactose is removed in whey protein isolate and even hydrolysate, dairy allergies stem from the proteins in milk. This means that whey protein would not be safe to consume if you have a dairy allergy or if whey causes GI distress in general. In this case, this is when you would want to opt for a pea protein powder. 

Too Much Can Cause Stomach Issues

Some body composition goals require a very high protein intake, so many choose to turn to protein powder to help them meet these needs. However, most people find that more than 50 grams of protein from whey gives them major stomach discomfort, likely due to the load of isolated amino acids.

How to Use Pea and Whey Protein for Weight Loss

When examining pea protein vs. whey for weight loss, is one better than the other? The fact is, you can use whey protein for weight loss in the same way you can use pea protein for weight loss. As we covered, both are surprisingly similar from a nutrition standpoint. Also, both contain high amounts of protein, which we’ve already discussed helps with making you feel full. Some studies even show pea protein as performing slightly better than whey at fighting cravings. 

Before we go on, it must be pointed out that protein powder is a supplement, meaning it should be used to supplement the food in your diet, not as a replacement. Generally speaking, food is going to be more satiating than protein powder and contain nutrients that both types of protein powder lack like antioxidants, minerals and fiber. 

Thus, try to get no more than 30% of your protein needs from protein powder and get the rest from sources of lean protein like low fat dairy, poultry, seafood and legumes. It should also be noted that, no matter how much protein you consume, you need to be in a calorie deficit to lose weight. 

Quick Tips to Prevent Overeating with Protein Powder

Now, if you want to use protein for weight loss, here are some methods you can try to prevent overeating:

• Drink a protein shake before going out to eat, so you don’t go overboard on the oversized portions

• Have a protein shake between meals as a low-calorie snack

• Blend your protein into a nutrient-dense smoothie by adding in low-fat milk or soy milk along with some frozen fruits for a low-calorie, grab-and-go breakfast

The Bottom Line on Pea and Whey Protein

When considering supplementing with pea protein vs. whey protein, although they come from very different sources, they have many of the same benefits and even a similar amino acid profile. When choosing a protein shake for resistance training, you may want to blend pea protein with rice protein so that you can get all of the essential amino acids found in whey.

Otherwise, pea protein is a wonderful substitute for whey if you adhere to a plant-based diet or are just sensitive to milk products. When using pea protein for weight loss, science has shown its effectiveness at preventing overeating. 

Neither whey nor pea protein can cause weight loss on their own, so make sure you are also eating a balanced diet rich in lean proteins, whole grains, and plenty of fruits and vegetables.