Basic Facts About Protein

Protein is the building material for the structure of the body. Protein is broken down into amino acids. Amino acids are the basis for synthesis of the body: bone, muscle, skin and brain. Moreover, amino acids are used to make nucleic acids, which form the genetic code as well as the molecules. These molecules store energy within the body. Diets lacking in proteins result in stunted growth in children. Proteins are the building blocks of enzymes, hormones and antibodies, all of which are essential in many biological processes. Some of these amino acids are deemed essential amino acids as they cannot be synthesized from other materials and thus must be part of the diet. Protein is abundant in dairy products, soybeans, meat and cereal; which are all constituents of a healthy balanced diet. In an average healthy person, proteins constitute about 15% of the body weight.

Role of protein in body

1. Proteins are necessary for growth. Fats and carbohydrates cannot be substituted for proteins, as they do not contain nitrogen.
2. The human body is constantly undergoing ‘wear and tear’, which is repaired by proteins.
3. Proteins supply raw materials for the formation of digestive juices, hormones, plasma proteins, hemoglobin, vitamins, and enzymes.
4. Each gram of protein supplies 4 kcal (17 kJ) of energy.
5. Proteins function as buffers, helping to maintain the pH of plasma, cerebrospinal fluid, intestinal secretions, etc, at a constant level.
6. Proteins aid transport of nutrients (e.g., lipoproteins) and drugs. Drugs bind to specific sites on the protein molecule; when combinations of drugs are administered, their effects depend on whether the protein-binding site is already utilized of free.

Understanding the importance of proteins is critical, because a failure to eat foods that contain these essential amino acids can lead to deficiency and adverse health effects. These effects can include fatigue, allergies, loss of memory, and even heart disease.

Foods rich in protein

Meat, fish eggs, milk and cheese are widely known to be good sources. Legumes such as beans, peanuts, peas and soy bean-derived foods, etc., are the best plant sources. Strict vegetarians depend upon these sources. Many cereals contain protein. Fruits and vegetables are only fair sources. Some of these sources are complementary. For example, cereal proteins are not especially high quality. But if they are combined with the proteins found in milk, the deficiencies in the cereal proteins are made up in the milk proteins. Cereal with milk is therefore a much better protein source than cereal alone.

Daily protein requirement

The Recommended dietary Allowance (RDA) is 0.75 grams per kilogram of body weight per day, which is 45-60 grams per day for an adult. Children require 1-2 gm/kg/day, with younger children and infants needing the most. Under conditions of hyper metabolism, the body will increase protein breakdown. The amount of breakdown may increase fourfold and protein breakdown in such patients may reach as much as 2-4 gm/kg/day. But this situation is uncommon and most patients under stress require no more than 1-1.25 gm/kg/day, about 50% more than the RDA.