The amount of muscle mass that you gain is directly proportional to the amount of protein you take into your system. The average daily intake should be around 400 grams of protein a day if your goal is to build substantial muscle mass. No matter what food you eat, its not possible to take so many grams with food alone. 125 - 157 grams is about the average that you can get through food and still eat healthy. So it makes sense to supplement your diet with protein powder.
Protein powder is a supplement and should be used as one. That means that you use it to compliment and supplement your diet and not replace it. Protein powder is also more cheaper that a meal that has the same amount of grams per serving. Also powder cannot give you other nutrients that whole food can, so make sure you use the power as pure supplement. The bulk of your dietary protein should in from fish, meats, chicken and eggs. Protein has amino acids that are important to building and maintaining muscles if you combine it with a diet and exercise plan. It also helps the production of red blood cells and boosts your immune system and gives you strong hair and healthy skin.
Be carefully when choosing protein powder though because some powder will have bad ingredients like aspartame, fructose and artificial colors. Chose one that has natural ingredients and not artificially sweetened. Make sure you do your research before you buy any powders and make sure that the brand is trusted and other people are using it etc.Thus there is a need to supplement your diet with protein powders when you are doing some vigorous weight training.This helps to build muscle mass that has a high metabolic value.