I try to keep a few things in mind as I review. There are 4 different kinds of protein bars: Whey, Protein Powder, Soy Protein, and Flaxseeds.
Whey is a natural substance from milk. It is the primary source of protein in the US. A gallon of milk contains 10 grams of protein (as opposed to the 20 to 30 grams that is found in most other kinds of protein bars). If you look at all the proteins in your body, most of them are present in whey. The whey protein is also one of the easiest to digest. It contains no lactose or caseins, which are the two main problems with most other protein bars.
Whey is the ideal kind of protein for your body because it can be easily absorbed and metabolized into energy rather than just being stored as fat in your body.
Whey is also a good source of essential amino acids, which are critical to the functioning of your body. For example, many essential amino acids are found in whey (proteins like lysine, arginine, isoleucine, leucine, valine, isoleucine, methionine, and glycine). Whey also contains calcium and magnesium. Whey protein has about 50 percent more of these two minerals than other types of proteins.