Protein is a fundamental amount of the human diet and can be found in a variety of foods. Protein is used by the body to both build and repair muscle tissue. It is a primary nutritional source for bodybuilders, athletes, and people concerned about their wellness.
Components of Protein
Like other macronutrients, protein is made up of hydrogen, carbon, oxygen, and most importantly, nitrogen. Nitrogen is important because it helps the body maintain an anabolic or muscle-building state (Schwarzenegger, 1998).
Some foods contain complete protein and offer all of the amino acids which are required to build muscle. This is also important because the body requires essential amino acids from outside sources to optimally build muscle. While the body produces some amino acids on its own, it requires outside amino acids to work effectively. These “ideal protein foods” are eggs, milk, fish, and various vegetables.
Best Types of Protein
But what are some of the best sources of protein? Our bodies metabolize and utilize different foods in different ways. The following information from Schwarzenegger (1998) provides the amount of protein (percentage by weight) and net utilization of that protein source. Ultimately, it explains how much protein is present in a food and how much of it can be used by the body to build muscle.
Food % Protein by Weight % Net Protein Utilization
Eggs 12% Protein by Weight – 94% Net Protein Utilization
Milk 4% Protein by Weight – 82% Net Protein Utilization
Fish 18-25% Protein by Weight – 80% Net Protein Utilization
Cheese 22-36% Protein by Weight – 70% Net Protein Utilization
Brown Rice 8% Protein by Weight 70% Net Protein Utilization
Meat/Fowl 19-31% Protein by Weight 68% Net Protein Utilization
Soybean Flour 42% Protein by Weight 61% Net Protein Utilization
It is obvious that eggs contain the greatest amount of usable protein with milk as the second most usable source. It is important to realize that just because a food contains a substantial amount of protein, that protein is not always usable by the body. Specifically, cheese has considerably more protein by weight than milk, yet milk protein can be better used by the body to build muscle.
Ultimately, not all foods are the same. It is clear that some are much better than others for protein utilization. It is a common misconception to ingest a food believing it to be healthy when in fact a healthier (and perhaps tastier food) exists.
It is reason that it becomes important to understand which common foods have substantial amounts of protein and a substantial amount of usable protein. For building muscle, maintaining weight and building a balanced and protein-rich diet, eggs, fish, and milk are prime choices and excellent sources of practical protein.