Proteins are present throughout the body, providing structure and helping create important substances required for good health. This nutrient is a necessary component of the human diet. The body cannot store proteins as it does fats and carbohydrates, so consuming enough every day is essential to good health.
Protein is considered one of the building blocks of the human body. Structurally, protein is a chain made up of different amino acids. There are many amino acids that combine in many different ways to form many different types of proteins. Twenty-two amino acids have been identified as crucial to human health, and nine of these must be consumed through your diet.
Functions
Found in every cell of the body, protein plays a role in the production of hormones, enzymes and other important substances. The role of the proteins are numerous, complex and varied. The protein hemoglobin is necessary for proper oxygenation of the blood, while the proteins making up antibodies help fight infection. Enzymes are a type of protein involved in many sequences required for proper body function, including digestion. Hormones are another class of proteins, helping to send messages throughout the body. Proteins also help build your muscles, skin and bone.
Dietary Protein
Two types of dietary protein exists -- complete and incomplete. Complete proteins, found in animal products, contain all nine amino acids that your body can't make on its own. Examples of complete protein foods include lamb, beef, chicken, fish and dairy products, such as milk and cheese. Incomplete proteins are plant-based foods such as vegetables, fruits, grains, legumes, nuts and seeds. You can combine two incomplete proteins, such as eating rice and beans, to consume all nine amino acids, thereby creating a complete protein meal. Other combinations are peanut butter and bread, and macaroni and cheese.
Recommendations
Most adults need about 60 g of protein a day. Three oz. of chicken contains about 21 g of protein, and you can add a 1 cup of low-fat milk to the meal for an additional 8 g of protein. For children, protein needs depend on weight; about a 1/2 g of protein is necessary for every pound of weight. For a child who is 40 lbs., 20 g of protein per day is necessary.
