Whey protein is arguably the most popular sports nutrition supplement these days. It has been shown to augment muscle protein synthesis, support fat burning, boost the immune system, improve insulin sensitivity and decrease appetite.
Whey protein comes in three main forms, but today we are focusing on 2: isolate and concentrate. Both forms contain whey protein. Whey isolate, which is made from whey concentrate, undergoes further processing which yields an end product with more protein per unit than whey concentrate. This processing results in a product that differs from whey concentrate in several important ways.
Pushing the liquid portion of milk through a filter creates whey protein. The material left behind is dried and forms whey protein concentrate. Concentrate contains varying amounts of fat and carbohydrates in the form of lactose. The percentage of protein varies from about 30% to about 80%, and includes a variety of protein breakdowns, many of which have significant biologic activity and health benefits.
It might be difficult to choose what type of protein supplement to choose, and how much to take. Because your body needs protein after a workout to recover, the most quickly absorbed is the best choice. Protein Isolates are more rapidly absorbed than concentrates. They contain a higher amount of protein per serving. This is important for people who are calorie restricting and want to consume as much real food as possible. While 5 grams of carbs (per serving of whey concentrate) may not seem like a lot, 2 shakes a day can mean a half of an apple. It is easy on the stomach too, especially if lactose intolerance is an issue. Concentrates contain significant amounts of lactose, so for those concerned with that, Protein Isolate is the better choice.
To sum it up, Weigh Protein Isolates contain more than 90% protein contents with minimal lactose and virtually no fat. The advantage of a good WPI is that it contains more protein and less fat, lactose, and ash then concentrates on a gram for gram basis. It absorbs more quickly into the body, and therefore it is the better choice post-workout.