Whey Protein Isolate

Whey protein is very popular in fitness minded circles. As such, it is available from many different brands and in many different forms. While the ingredients may seem to blend together, they all have slightly different effects.

What Is It?

Whey protein isolate [1] is a powdered protein used either as a supplement or food additive. This is the more processed version of whey protein concentrate that has undergone additional treatment to remove almost all traces of lactose, carbohydrate, and fat. Whey protein isolate is at least 90 percent protein, in direct contrast to whey protein concentrate which is between 30 and 80 percent protein depending on quality.

The additionally processing denatures the proteins which doesn’t change the way they act on our muscles, but is thought by some authorities to make this form of whey inferior to whey protein concentrate due to the limitation of the biologic activity of some peptides found in whey.

What Is Its Biological Role?

Whey protein is one of two proteins that comes from milk, the other being casein. Proteins in general have a wide variety of functions in the body, but whey and casein protein are known to specifically aid in muscle growth and repair.[2]

This is why they are favored as the protein source for shakes and nutritional bars. When we consume protein, our stomach acid breaks the protein molecules down into their building blocks known as peptides. By the time the peptides make it into the small intestine they have undergone yet another reduction, into the even smaller building blocks we call amino acids.

Amino acids are the essential protein building, and what our body uses to complete the biochemical reactions for which we need protein. The small intestine is lined with special cells that can carry amino acids through the intestinal lining and into the bloodstream, where they can be transported throughout the body to areas where they are needed most.

How quickly these amino acids reach the bloodstream and are able to effect change depends on the particular protein source, as different types of protein are broken down at different rates during the digestive process. Whey protein breaks down fairly quickly and can be easily absorbed by the body.

Once the proteins are broken down into amino acids and can work in the body, however, they don’t stick around for long. Due to their high sulfur content they are flushed out of the body quite quickly compared to other source, though not before their special amino acid content allows them to increase the body’s rate of protein synthesis.

How Does It Help Bodybuilders and People Who Work Out?

Whey protein isolate is a favorite for bodybuilders and lean athletes alike. After an intense workout, whey isolates are an excellent choice as a recovery drink. The protein hits the body quickly, and assists in the body’s natural repair process that heals and grows the muscles.

It doesn’t stay in the body quite as long as other protein, so is better as a post-workout drink than pre-workout. Isolates compared to other whey protein produced also contain very few calories because of their extremely high protein content.

What Foods Contain It?

Whey protein isolate is not naturally occurring; rather, as a synthesized food additive it is found in processed foods. This can range from protein powders and nutritional bars to baked goods.

How Much Of It Do You Need?

There is no officially recognized recommendation for whey isolate consumption, though it can be a healthful part of your total protein intake.[3] Your daily protein requirements depend of your size, amount of muscle, and activity level.

If consuming whey protein isolate in powdered form as the main ingredient in a protein shake or as part of a nutritional bar, the best advice to follow the serving size information on the packaging. This is because protein shakes mixes and bars do not always contain the same ratios of ingredients, and so total protein consumption and serving sizes may vary.

Are There Risks Associated With Consuming Too Much Of It?

A consistent diet that is so high in protein and so low in carbohydrates that it becomes unbalanced can cause health complications. The biggest concern is liver damage as your liver struggles to filter all of the protein wastes out of your body in the absence of other nutrients. It should be noted that this concern applies to all sources of protein, not just whey protein isolate.

Are There Risks Associated With Consuming Too Little Of It?

Whey protein isolate is not considered a necessary part of a healthful, balanced diet. If you avoid consuming it you will not experience any adverse affects, as long as you are diligent in ensuring you meet your daily protein requirements from other sources.

Final Take

A favorite for protein shake lovers, whey protein isolate may make a good addition to your diet and exercise regime.


[1] Dr. Seltzer, Charlie. Whey Concentrate vs Isolate: What’s The Difference?. Builtlean.com, 2016.

[2] Dr. Axe, Josh. Casein Protein vs Whey Protein: The Benefits of Protein Powder Draxe.com, 2015.

[3] WebMD. Daily Protein Requirements: Are You Getting Enough?. Webmd,com, 2016.