Whey Protein vs. Plant Protein: A Complete Guide

Whey Protein vs. Plant Protein: A Complete Guide

Whey Protein vs. Plant Protein: A Complete Guide

If you’re considering adding protein powder to your health and wellness regimen, you might be wondering where to start. A trip to your local health food store will reveal a variety of choices ranging from common whey proteins and soy proteins to newer options like collagen, brown rice, hemp, or pea protein. 

Different protein supplements have different nutrient profiles. Each can be more or less useful, depending on your fitness goals, personal health, and how well your body processes the ingredients and turns them into usable fuel. 

For example, if you’re vegetarian or vegan and looking for a plant protein, products with whey, egg, milk, and collagen are off-limits. If you’re on a paleo diet, you might be limited to collagen or egg protein options. If your goal is weight loss, you’ll likely want something with fewer total calories than someone looking to build muscle or bulk up.

Let’s review the various options, specifically whey protein vs. plant protein, to help you determine which one is the right choice for you.

Protein Powder Basics

Whey Protein vs. Plant Protein:  Close-up image of protein powder in a scoop

The common goal behind just about all types of protein powders on the market is to get more usable protein into your system and, in some way, optimize your health. For some, the goal might be weight loss, fat loss, or muscle gain. For others, it could be to improve athletic performance or post-surgical nutrition. To that end, nearly all commercial protein powders contain the nine essential amino acids, making them complete sources of protein. 

Amino acids are the building blocks of protein in your body, and while your body can produce many of them on its own, there are nine essential amino acids that have to be sourced through your diet. They include:

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

Branched-chain amino acids (BCAAs) are the most important of the nine essentials when it comes to building and retaining skeletal muscle mass. Specifically, the three BCAAs are ​​valine, leucine, and isoleucine, all of which are quite high in pea protein. 

It’s important to maintain adequate protein intake as we age or start a new physical activity routine to avoid injury or muscle loss over time. As such, choose a protein that caters to your particular health status and goals.

Also, when choosing your protein source, a good place to start is to distinguish between animal protein and plant protein. While animal proteins naturally contain all nine essential amino acids, there are only a few plant-based sources that are considered complete proteins. Here’s a quick breakdown of each option.

Plant Protein Powders

Single-source plant proteins that offer a complete essential amino acid profile include soy, chia, hemp, amaranth, buckwheat, and quinoa. That’s why you’ll often see soy protein powders with no other protein ingredients. (The others are a little less commonly available on their own, although hemp proteins are growing in popularity). 

If you’re wary of soy, there are other vegan protein options. There are combinations of seeds, grains, and/or legumes, which together create the complete protein you’re looking for. For example, it’s common to see pea and rice protein combined into a single formula to get all nine essentials. 

Animal-Sourced Protein Powders

The most popular and easily accessible form of animal-based protein powder is whey protein. Whey protein powders come in two forms: whey protein isolate and whey protein concentrate. Whey is a dairy product, a byproduct of cheese production that’s powdered and dried for commercial use. 

Whey protein concentrate is closer to a whole food than isolate, meaning it contains other naturally occurring components beyond pure protein. While for some, a product closer to a whole food is more appealing, one of the components in concentrate is lactose. So if you’re lactose-intolerant, whey concentrate isn’t for you. 

Whey protein isolate, on the other hand, goes through a longer process that extracts nearly everything that isn’t protein, leaving the isolated protein behind. For some, this additional processing is enough to prevent bloating or other dairy-related symptoms. But for others, whey is off the table due to undesirable digestive reactions. 

There are some completely lactose-free whey products such as ioWhey, which has been processed to increase protein absorption and lower digestive discomfort. 

Whey Protein vs. Plant Protein: Performance

Woman working out with heavy ropes

When we refer to performance, we’re talking about how the protein powder you choose performs in your body and your own personal performance. Everybody needs to consume enough protein to reach their performance goals, but since everyone is different and everyone has different goals, the amount of protein you need can change. 

Factors that determine your protein needs include:

  • Activity level
  • Age
  • Goals (weight loss, weight gain, rehabilitation after an injury, maintenance, etc.)

For example, bodybuilders will need more protein — and other sources of calories — during their bulking phase for muscle protein synthesis. Conversely, they’ll likely cut down on protein and all other calorie sources during their cutting phase. As you can see, needs can change over time even when it’s just for one person. Let’s review how activity level, age, and health goals impact the type of protein you should choose.

Activity Level and Age

The recommended daily allowance (RDA) for protein is 0.8 grams per kilogram of bodyweight. But that’s just the minimum for a sedentary person to avoid getting sick or protein deficient. This calculation isn’t aimed at optimizing your health or building muscle mass. In fact, some dieticians recommend twice that number for the average adult under 50 years of age. It seems that more research is needed on the topic of “adequate” vs. “optimal.”

The American College of Sports Medicine (ACSM) recommends adding more protein than the RDA after the age of 50 in order to account for decreasing efficiency in protein synthesis that comes with age (from 0.8 to 1 gram per kilogram). 

The ACSM also recommends that active adults who lift weights or engage in other strength training activities increase their protein intake to 1.2-1.7 grams per kilogram and include a high-protein shake or meal within one hour of resistance training. Studies show that the window immediately following a hard workout is the most effective time to aid your body in building muscle

When it comes to choosing which type of protein is more suitable for a more active lifestyle, the jury is still out. One pilot study comparing the use of whey protein vs. plant protein (pea) during eight weeks of high-intensity training showed virtually no difference in outcomes between the two proteins.

Your Goals

When it comes to setting a health goal and choosing protein supplements to help you accomplish it, the contents of the product are just as important as whether you choose a plant or whey protein powder. 

If you want your protein shake to be a meal replacement, you might consider a nutrient-dense option that has a full spectrum of antioxidants, vitamins, and minerals. If you’re looking for post-workout fueling, then a simple protein-only formula could work. 

For a fat loss goal, you’ll want a product that limits total carbohydrates, has low or no sugar, and relatively low calorie count. And since your protein shake will likely replace a meal, you’ll want to consider one with more nutrients.

For a muscle-building goal, you’ll want to focus on the protein supplementation directly after your workout to support muscle recovery and growth over time. The nutrient density of the protein powder you choose will depend on whether you’re looking to have more than one shake per day and whether you’re replacing meals. 

Ideally, you’ll be using a highly bioavailable source of protein immediately after a workout in order to get the biggest bang for your buck. The Journal of Food Processing & Technology conducted a study comparing ioWhey to standard whey isolate. The results showed that increased performance and increased lean muscle mass for the ioWhey group far exceeded the control group taking non-optimized whey.

If you’re replacing meals, make sure the product you choose has adequate fat and carbs, or that you add them yourself when you blend up your drink.

Plant Protein vs. Whey Protein: Digestion

Whey Protein vs. Plant Protein:  Woman scooping green protein powder out of a glass jar

How your body handles various food ingredients will help you narrow down your choices. We mentioned the lactose issue with certain whey proteins, but some plant sources of protein can also cause digestive discomfort. However, many protein powder companies add in digestive enzymes with the goal of helping make their products more digestible, whether they’re animal-based or plant-based. Unfortunately, this approach can have a significantly negative impact on the taste profile of the protein powder, making it a less-than-ideal tactic. Furthermore, there is limited evidence that enzymes actually improve absorption.

That said, sometimes the additives intended to increase nutritional benefits can have their own side effects. For example, many protein powders on the market now (especially the plant-based ones) contain prebiotics and probiotics alongside the enzymes for digestion. 

If you don’t digest FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) very well, some of those prebiotics can cause bloat and gassiness for you. Furthermore, legumes naturally contain FODMAPs. While the processing of soy and pea protein filters out much of the FODMAP content, you’ll need to see for yourself if you can use legume-based protein powders.

Absorption and Assimilation

Athletic man wearing headphones and holding a water bottle

Whatever you choose, the way your body processes and assimilates the contents will determine how well it performs for you. If your protein powder moves right through you without being adequately absorbed for use, then your chances of muscle growth and fitness gains won’t be very high. Studies show that animal proteins like whey are more readily used by the body than most plant proteins. 

However, certain formulations of plant proteins and the addition of certain individual amino acids can improve the absorption of plant protein. And since plants are a more sustainable food source for our planet, advancements will likely continue to improve the absorption of plant-based proteins.

Case in point: ioWhey and ioPea proteins are specially formulated for optimal absorption with several clinical trials showing that ioPea is even more easily absorbed than non-optimized whey protein.

Your Body, Your Protein

Now that you’ve learned more about your options for whey protein vs. plant protein, it’s time to find out what’s best for you. You may be an omnivore interested in top-quality whey protein that doesn’t contain lactose. Or you might be leaning toward a plant-based option like a pea or brown rice protein. 

As you begin testing things out, listen to your body and pay attention to what it’s telling you. Notice how your gut feels after your protein shake, and notice how your body feels after a workout with or without your supplement. You might find that your initial instincts about which type of protein would work for you were right on, or you might be surprised at what your body needs. Learn more about how Ingredient Optimized proteins stack up with our list of human clinical studies and preclinical research