by Jeff S. Volek, Ph.D., R.D.
Selecting a whey protein supplement can be daunting, considering the vast number of companies selling whey in different forms.
The two most common forms are whey concentrate and whey isolate
The main difference is that isolates are more pure than concentrates, meaning other non-protein components have been partially removed to “isolate” the whey protein. Many concentrates are 80% protein, which means on a dry basis, 80% of the total weight is protein. As an example, 100g of whey concentrate contains about 400 calories, 82g of protein along with about 9g of carbohydrates (about half is lactose), 6g of fat and 150 mg of cholesterol.
Whey isolates are typically about 92% protein (dry basis), meaning you get more protein per equivalent dose. The same 100g of whey isolate delivers less calories (about 370 calories), but with more protein (92g) and considerably less total carbohydrate, lactose, fat and cholesterol.
Most whey concentrates and isolates are available as intact proteins, but either can be also hydrolyzed
Hydrolysates have been partially broken down by exposing the protein to heat, acid or enzymes that break apart the bonds linking amino acids. This makes it taste more bitter, but also allows it to absorb more rapidly than a concentrate or isolate. Concentrates and isolates are already fast-digesting, so a hydrolysate, which digests minimally faster, may not be worth the taste tradeoff and extra cost for the small benefit.
Whey protein in any of its forms has an excellent digestibility and amino acid profile. Since isolates and hydrolyzed proteins are more expensive, most whey supplement makers add very little of them to their formulas, if any.
As long as you don’t mind the few extra grams of carbohydrates and fat, and you’re not lactose intolerant, whey concentrates are the most economical choice and are clearly the best selling form of whey protein on the market.
