Whey protein is derived from cow’s milk and is taken to add additional protein into an existing diet. Getting enough protein in your diet is very important even if you don’t train. Protein is used by the body to aid in repair and recovery amongst many other vital functions. Whey protein is most commonly taken by gym goers to support recovery and development of new muscle tissue whilst it is also a supplement of choice for vegetarians who simply use it to support a meat free diet. Just remember that eggs, steak, chicken, salmon, dairy, nuts and grains are all excellent sources of protein. If you are focused heavily on what you eat and are passionate in the kitchen then don’t waste your money. If however you are on the go all of the time and have little time for food prep then perhaps a good whey protein supplement is for you. Whey protein is most commonly taken in powder form and mixed into milk or water to create a drink although it can be purchased in bars which some find easy and convenient after a workout.

Bodybuilders may supplement their diets with protein for reasons of convenience, lower cost (relative to meat and fish products), ease of preparation, and to avoid the concurrent consumption of carbohydrates and fats. Additionally, some argue that bodybuilders, by virtue of their unique training and goals, require higher-than-average quantities of protein to support maximal muscle growth.However, there is no scientific consensus for bodybuilders to consume more protein than the recommended dietary allowance. Protein supplements are sold in ready-to-drink shakes, bars, meal replacement products (see below), bites, oats, gels and powders. Protein powders are the most popular and may have flavoring added for palatability. The powder is usually mixed with water, milk or fruit juice and is generally consumed immediately before and after exercising or in place of a meal. The sources of protein are as follows and differ in protein quality depending on their amino acid profile and digestibility:

• Whey protein contains high levels of all the essential amino acids and branched-chain amino acids. It also has the highest content of the amino acid cysteine, which aids in the biosynthesis of glutathione. For bodybuilders, whey protein provides amino acids used to aid in muscle recovery. Whey protein is derived from the process of making cheese from milk. There are three types of whey protein: whey concentrate, whey isolate, and whey hydrolysate. Whey concentrate is 29–89% protein by weight whereas whey isolate is 90%+ protein by weight. Whey hydrolysate is enzymatically predigested and therefore has the highest rate of digestion of all protein types.
• Casein protein (or milk protein) has glutamine, and casomorphin.

Some nutritionists have suggested that higher calcium excretion may be due to a corresponding increase in protein-induced calcium absorption in the intestines.

Whey protein is commonly marketed as a dietary supplement, and various health claims have been attributed to it in the alternative medicine community. Although whey proteins are responsible for some milk allergies, the major allergens in milk are the caseins. It is sold as a nutritional supplement.

Whey is the primary ingredient in most protein powders, which are used primarily by athletes and bodybuilders to obtain the necessary amounts of protein for muscle building/maintenance on a daily basis. Whey protein has a high level of leucine, one of the three branched-chain amino acids, making it ideal for muscle growth and repair.Whey is pasteurized, just like any milk, to assure that no harmful bacteria are breeding in the liquid. It is heated to 70–80 °C (158–176 °F) and is then cooled back down to 4 °C (39 °F). Studies have shown that this process of using extreme temperatures eliminates 99.7% of bacteria without coagulating the protein into a solid mass. Next, the whey must be filtered, and so is loaded into a massive web of ceramic filters and stainless steel turbines. These machines work to separate out the lactose as well as the fats, leaving a liquid of 90% whey protein.

Hydrolysates are whey proteins that are predigested and partially hydrolyzed for the purpose of easier metabolizing, but their cost is generally higher. Highly hydrolysed whey may be less allergenic than other forms of whey, due to the fact that the short chain peptides obtained by hydrolysis are less antigenic, because of the elimination of sequential epitopes.

Native whey protein is extracted from skim milk, not obtained as a byproduct of cheese production, and is produced as a concentrate and isolate.