The main difference between whey protein isolate and whey protein concentrate is protein content.

Whey protein concentrate is the most common form of whey protein, and has the biggest variation in terms of its content. A product can be labeled "concentrate" so long as 35 to 80% of it's content by weight is protein.  

Whey protein isolate, meanwhile, must be at least 90% protein. 

Each type of whey protein can play a role in an athlete's diet. In this article, we'll discuss the pros and cons of both.

Why Protein Intake Matters More Than You Think

Protein might be the most misunderstood macronutrient. You probably know it as an important part of building muscle, but it also plays an essential role in fat loss, recovery, aging, and even bone health.

While the majority of protein should come from whole food sources like beef, chicken, fish, eggs, dairy, and vegan sources like rice and beans, most people struggle to get enough protein in their diets.

Enter protein powders.

The Role of Protein Powder in Your Diet

While it's classified as a supplement, a good protein powder is essentially the same thing as eating a whole food, it's just delivered in a concentrated, more convenient form.

Before you buy just any old protein, the value of good protein powder depends on a few very important variables.

Sourcing helps determine the quality of a protein, and, in particular, whey protein is considered the gold standard because it has all of the amino acids your body needs to fuel muscle gain, fat loss, and recovery.

Understanding that whey is good is the easy part. But, before you grab any old whey powder, the details will make all the difference in ensuring your giving your body what it needs...and not being ripped off.

What is Whey Protein?

Whey is derived from milk and was originally a byproduct of the cheese-making process (enzymes are added to milk to separate the liquid from curds). Then, supplement makers realized that the “waste” could be used as a high-quality, valuable protein.

Because created whey is a multi-step process of removing the protein from milk, you have many different variations. 

Most research on protein powders has found that whey protein is the best way to go for weight loss and muscle building. Whey protein contains an ideal mix of essential amino acids. And when consumed, whey protein delivers results.

For instance, a study in The Journal of Nutrition compared to soy protein to whey protein. Participants whose diets included whey protein for 23 weeks had less body fat and a smaller waist than those who chose soy.

In fact, dieters who included whey protein in their eating plan doubled their fat loss compared with those who ate the same number of calories but didn't drink any shakes.

(If you’re looking for a non-dairy protein powder, research suggests that pea protein is very similar to whey, which is why if you are on a plant-based diet, pea protein isolate is your best option).

Whey protein is primarily offered as two different variations: whey protein concentrate and whey protein isolate. Knowing the difference (and what to look for on a label) will go a long way to ensuring you get the most out of your protein supplements.

What is Whey Protein Concentrate?

Whey protein concentrate is the most basic form of whey protein. By law, being labeled as concentrate means that the product needs to be at least 35% to 80% protein by weight. So, if you scoop out 100g of protein powder it can be called concentrate if anywhere between 35 and 80g of that is protein.

There is not much else to a whey protein concentrate. If you want an idea of how whey concentrate is created, here’s a good visual: If you imagine whey falling off a conveyor belt into buckets, all you need to do is filter out impurities, dehydrate it, flavor it chocolate, and call it “Delicious Chocolate Whey Concentrate.” (Coming soon to a supplement store near you!). Some supplement companies may do more than that to their concentrate products, but it is not required.

With such a simple process, concentrates also tend to be the cheapest sources of protein supplementation. This doesn’t mean the product is bad, but it does mean that it’s not the highest purity for a protein powder.

What Is Whey Protein Isolate?

Whey protein isolate, on the other hand, is a more pure form of protein. In order to be an isolate, the supplement must be more than 90% protein by weight.

Going back to our 100g example, if you scoop out 100g of whey isolate you will get over 90g of protein, which shows you what a significant difference it is compared to concentrate.

Whey isolates tend to have a higher price relative to concentrates for four reasons:

1) Protein quality: Because it’s a more pure form a protein, you get a higher protein-to-calorie ratio

2) Protein purity: Whey protein isolate filters out the rest of the macronutrients, meaning you have fewer carbs, sugar, and fat

3) Digestion: The micronutrition is upgraded as well, meaning things like lactose are removed. In general, whey protein isolate has less than 1% lactose, meaning it's easier on your stomach if you have any dairy sensitivities.

4) Improved mixability. Because of reasons 3 and 4, whey protein isolate has better solubility, which tends to make it a smoother, better tasting protein smoothie.

What About Whey Protein Hydrolysate?

Hydrolysate is a protein that is enzymatically and acid-treated to reduce particle size and destroy “quaternary protein structures.” (That’s a mouthful; but it means say bye-bye to any bioactive immunoglobulins, which can help support immune function.).

The origin of hydrolysis in dietary protein arose from a need to make baby formulas non-allergenic. Due to low particle size, hydrolysates are very water-soluble, but they offer a very bitter taste. This is because the amino acid proline is no longer being constrained in a protein structure and it being free to assault your tastebuds with incredible bitterness.

Hydrolysates are absorbed more quickly than isolates, but there’s no research to suggest that the faster speed has any added benefit for muscle gain, fat loss, or recovery. In other words, you’ll spend more money on hydrolysates for an unknown and unqualified benefit.

What’s the Best Whey Protein for You?

Both whey protein concentrate and whey protein isolate have proven benefits, but whey protein isolate is a more pure form of whey protein and has a guaranteed level of quality.

If you buy a concentrate, it's possible that you're taking a protein that is only 30% protein by weight. Whereas if you use whey protein isolate, you're guaranteed a minimum of 90% protein by weight.

For that reason, whey protein isolate is a safer route because you're less likely to provide your body with deceiving levels of proteins and amino acids you need to help support your goals. 

If you do choose to go with a concentrate, try to look for brands that are NSF Certified for Sport, which does a 3rd-party analysis to help guarantee quality. 

Related: What About Collagen Protein - Is It Useful?