Nutrition Information And Protein

Protein belongs to a class of nutrient called macronutrients, which are nutrients of which your body requires large amounts. Macronutrients also provide your body with energy in the form of calories. Dietary intake of the three macronutrients -- carbohydrates, fat and protein -- will help your body stay healthy.

Amino Acids

Proteins are composed of smaller units called amino acids. The order in which amino acids combine together determines what type of protein is made. There are a total of 20 amino acids. Nine of these amino acids are called essential amino acids because your body cannot make them and they must be consumed through the foods you eat. The remaining 11 amino acids are called nonessential amino acids. Because your body has the ability to make them, you do not need to consume nonessential amino acids in your diet.

Types

Proteins are classified into two types based on their amino acid profile. Proteins that contain all of the nine essential amino acids as well as some of the 11 nonessential amino acids are called complete proteins. A protein that is low in one or more of the essential amino acids is called an incomplete protein. Because they provide you with all of the essential amino acids, complete proteins are generally considered higher-quality proteins. Most proteins that come from animal sources, such as meat, fish, poultry dairy and eggs, are complete proteins, whereas most proteins from plant sources, such as nuts and beans, are incomplete proteins. It is important to note, however, that incomplete proteins are just as essential to a healthy diet as complete proteins.

Functions

Proteins play several important roles in your body. Collagen, which is the most abundant protein in your body, provides structural support to your bones, blood vessels, teeth and skin. Proteins also act as enzymes, which ensure that chemical reactions are able to take place. Proteins help maintain fluid balance and help alter the pH of your body fluids to maintain acid-base balance as well. Proteins also act as transport mechanisms to carry substances, such as oxygen, waste products and vitamins through your blood. Proteins are also needed to create antibodies, which help your immune system fight off potentially harmful substances.

Daily Needs

There are two ways to determine your daily protein needs. The first way is based on body weight. Adults generally require 0.8 g of protein per 0.45 pounds of body weight. If you are a 150-pound adult, your protein needs would be approximately 55 g per day.

The other way to calculate protein needs is based on your calorie intake. Protein, which provides 4 calories per gram, should account for between 10 and 35 percent of your daily calories. Using this method, someone on a 2,000-calorie-per-day diet would need 50 g to 175 g of protein daily.