How m­uch?

The answer is probably less than you think. If you eat a two-egg omelet with cheese, you've probably had as much protein as you need all day. Most adults need only two or three servings, and a serving is fairly small: two or three ounces of fish; one egg; a few spoonfuls of peanut butter; an ounce of cheese; half a cup of beans. Few adults actually need protein supplements [source: Medline].

Whey Protein at Work in Your Body

­is vital to your body's function. It helps your cells grow, replace themselves and repair themselves. In fact, protein is a component of every major body system and every fluid except bile and urine.

Your body makes some proteins on its own, from the 12 amino acids it can produce. The other nine amino acids you must get from dietary protein. Whey protein is one such source, and it provides all nine amino acids. Basically, it works in your body the same way, say, a steak does.

However, you absorb whey protein much faster than you would absorb a steak. The faster your body gets the protein, the more quickly it can start building new muscle. And most whey protein is low-fat or fat-free, whereas a steak is not.

The amount of protein the body needs depends on the body. Opinions vary as to how best to calculate it, but you should take into account your body weight, your body fat composition, your activity level and your nutritional goals. A good rule of thumb is 0.8 grams of protein for every kilogram of body weight (.08 g per 2.2 pounds) -- but 150 percent to 200 percent of that amount if you're an athlete in training [source: Definition of Wellness].

What if you consume more than that? The protein you don't need doesn't get stored as muscle-in-waiting. Your body breaks it down into amino acids, then into fatty acids and sugars. These chemicals travel to the liver, which converts them into cholesterol and fat.

Read on for a look at the potential benefits of whey protein.