Whey protein, commonly used in protein supplementation, is a by-product of the cheese manufacturing process. In simple terms, whey protein is derived from the remaining solids in the liquid left after cheese coagulates from cow's milk. Like most animal-based proteins – dairy in this case – whey is a complete protein that contains all nine essential amino acids (these amino acids can not be biosynthesized by the body and must be taken from dietary sources). Whey protein, either in its concentrate, isolate, or sometimes in hydrolysate (rarely) form is used as protein bodybuilding supplements, meant to saturate the skeletal muscle cells with amino acids to prevent protein catabolism and help them improve their repair and recovery rate after training .
Natural or dietary proteins can be found in a host of food types. When thinking protein, most people think meat or animal-based products, for good reason: meat is an excellent source of complete proteins, although it also contains relatively high concentrations of fat and cholesterol. This is highly dependent on the type of meat; turkey breast has 17% protein content per weight, but is very low in fat while beef can contain up to 35% protein per weight, but just as much in fat. But meat is strictly the only source of protein available. Some vegetables, particularly legumes such as beans, chick peas, etcetera, contain high levels of proteins and almost no fat, making them favorites of vegetarians and vegans who may need to pay closer attention to their protein intake.
Unfortunately, vegetable proteins are not complete; they do not contain all nine essential amino acids necessary to good health. This is easily counter-through protein combining, a practice in which several types of foods will be eaten together to ensure that all amino acids are presents; a good example of that that ubiquitous rice and bean dishes.
Natural protein and Whey protein have different uses, and under no circumstances should supplements, such as whey protein supplement, be used to completely replace dietary protein sources.
Dietary protein sources should meet everyone's – including athletes and bodybuilders – baseline protein needs. Protein obtained through food is highly bioavailable, and contains a host of vitamins, enzymes, dietary fiber and other nutrients that are absolutely essential to good health that will not be available in supplements, no matter how good. Exception in very specific circumstances, no oneides athletes and bodybuilders should need protein supplementation.
Where whey protein supplements truly come into their own is to grow lean muscle mass. Whey supplements help bodybuilders and athletes saturate their skeletal muscle cells so as to allow them all the amino acids that they need to grow during the recovery period after workouts, as well as during sleeping periods. To maximize saturation, experts recommend that protein supplements be taken as close as possible to the training period; Opinions differ as to whether before or after is preferred. Whey protein supplements, commonly available as powder to be mixed with water, milk or juice, or in convenient low-carbohydrate bar form are ideal for this function, as they can be consumed at exactly the right time.