Health benefits of proteins include production and smooth functioning of enzymes and hormones and a proper cellular and muscular health. They facilitate molecular transportation, cell repair, and regeneration and provide mechanical and structural support to the bones and skin. Consumption of adequate protein ensures strong immune defense, efficient signaling of nerves and impulses, healthy hair, and maintenance of fluid balance in the body. Protein can also turn into an energy provider when required by the body. 
Proteins are a group of biological compounds which are present in every live cell, organ, and tissue of the body. It is there in the form of enzymes, antibodies, hormones, and much more. Meaning ‘first’ or ‘of prime importance’ in Greek, proteins participate in every cellular process occurring in the body. They are responsible for the formation, regulation, repair, and protection of the body of each organism. They execute a range of functions within living beings including catalysis of enzymes, DNA replication communication, and coordination within the cells, molecular transportation from one location to another. 
Sources of Protein
Good sources of proteins are not hard to find for both vegetarians and non-vegetarians. Vegetarians can choose from nuts, seeds, soy products like tofu, dairy products, and legumes including a variety of beans such as pinto beans, kidney beans, garbanzo beans, and split peas. Meat eaters can choose from eggs, turkey, cooked lean meat, and fish. 
Types of Protein
Proteins can be classified into three main groups: 
Globular Proteins: Globular proteins work in the water environment as antibodies and enzymes.
Membrane Proteins: Membrane proteins work in the cell membrane and perform functions like membrane transport and signaling. 
Fibrous Proteins: Fibrous proteins are structured proteins which are found in muscles, bones, ligaments such as keratin which is present in the nails, hair or collagen which is present in the skin.
What are Amino Acids?
Proteins consist of multiple chains of amino acids and are considered the building blocks of our life. Digestion or breaking down of protein yields a range of amino acids which is utilized by our body for overall growth, repairing tissues and break down of food. 
Types of Amino Acids
Amino acids can be divided into three groups: 
Essential Amino Acids: These amino acids cannot be synthesized by the body and must be provided through the food.There are nine essential amino acids namely histidine, isoleucine, leucine, lycine, methionine, phenylalanine, threonine, tryptophan, valine.
Non-essential Amino Acids: These amino acids are formed by the body either from the breakdown of proteins or from the essential amino acids. Alanines, asparagine, aspartic acid, glutamic acid are non-essential amino acids.
Conditional Amino Acids: These amino acids are essential only during stress or sickness. Conditional amino acids are arginine, cysteine, glutamine, glycine, ornithine, proline, serine, and tyrosine.
Nutritional Value of Proteins
The amount of amino acid present in proteins determines their nutritional value which may vary for different foods. For instance, soy products and animal proteins contain all essential amino acids whereas; the plant proteins are generally deficient in few amino acids. It is advisable for the people following strictly vegetarian or vegan diet to include and combine various foods with a range of amino acids to fulfill their daily requirement. 
Health Benefits of Proteins
Amazing health benefits of proteins include a better muscular health, stronger immune system, healthy hair, and many more.
Improved Muscular Health
Proteins play an important role in muscle contraction and coordination. They are present in the muscle tissues in the form of many microfilaments and provide muscle structure. Muscle growth depends on the adequacy of proteins in the body. It is extremely important to create a balance between the rate of muscle protein synthesis and the breakdown of these muscle proteins. The rate of breakdown of muscle proteins varies depending upon specific conditions, for example, the requirement of protein is different during old age when the breakdown of muscles accelerates and is different for strength trainers who would also need to consider perfect timing along with the amount of protein intake.     
Stronger Immune System
Proteins are vital to building a stronger immune system.The body runs a mechanism of self-defense and protects itself from various infections and diseases with the help of antibodies. These antibodies are specific proteins which have the ability to detect foreign elements also known as antigens. The body responds to the antigens by the production of specific antibodies and deactivates it. 
Improved Nervous System
Another important task performed by proteins is the smooth functioning of nervous system. The nervous system of the body is activated whenever it is triggered and in turn, responds with an appropriate reaction. The receptor sites present in the nervous system, which are accountable for the prompt response comprise of protein complexes. These receptor proteins assist in the transmission of nerve signals within the cells and regulate the central nervous system. 
Balancing and regulation of fluids present in the body is another critical task performed by the proteins attributing to their effect on osmosis. As water is drawn towards the protein, better the quantity of proteins within a cell, more balanced would be the water content present in it. Drop in the levels of proteins results in a fluid imbalance which may lead to the deviation of acidity or ‘ph’ value in the body from the normal range. Fluid imbalance in the blood may result in leakage of fluid in the blood vessels, which may get accumulated in the tissues causing edema. Fluid balance in the body is also important for other functions such as the functioning of muscles and nerve cells. 
Proteins can also benefit the body by being a source of energy. Consumption of the diet which fails to provide enough energy to the body such as during starvation or weight-loss programs causes the body to use its own functional proteins in order to compensate. As the body does not store extra proteins, enzymes, and muscle proteins break down to yield amino acids to provide energy or synthesize glucose and ensure a continuous supply of energy to the cells. 
Proteins help in maintaining healthy hair and protects them from damage. Studies conducted in this regard have advocated the role of proteins as a modulator of hair growth. Attributing to these beneficial effects, proteins are widely used in the manufacturing of hair care products such as conditioners.  
Enzymes are protein catalysts which play an important role in all the biochemical processes and reactions occurring in the body. Without altering themselves, these enzymes accelerate the rate of all the chemical events. The performance of the chemical processes depends upon the measure of enzymes present in the body. A slower rate of reactions and processes indicate a deficit of necessary enzymes in the body. Various protein hormones such as insulin, growth hormone, and glucagon also comprise of amino acids which play an important role in various functions operating in the body.
Another major task performed by proteins is the transportation and storage of various substances across the cell membranes. This is vital for smooth flow of blood and nourishment of the body. For instance, a passage of oxygen in the red blood cells is done by an important protein called hemoglobin. Another protein called ferritin is responsible for storing iron and blood in the liver.
Proteins are also responsible for extending mechanical support and strength to various tissues which suffer from constant wear and tear such as skin. Collagen is an important and abundant fibrous protein which provides strength to the cells, tissues, and organ such as skin which needs to be revitalized on a continuous basis. A study conducted on UV-irradiated subjects has revealed positive results of collagen with respect to restoration of dermal collagen protein synthesis. The healthy, low wrinkled, and youthful appearance of the skin largely depends on the levels of collagen protein in the body.  
Cell & Tissue Regeneration
Renewal and restoration of cells and tissues are extremely vital for the maintenance of the healthy body. The body needs a constant supply of amino acids for the formation of proteins that manufacture new cells and tissues such as nails, hair, and skin. The cells present in the digestive system, skin, and blood do not last for more than a couple of weeks and begin to perish. That’s the time for the creation and replenishment of new and healthy cells to replace the deceased ones. This process of revival of new cells and tissues performed by proteins help sustain good health. Proteins are also used for manufacturing of cell regenerative medicines.  
Improved Bone Health
As already mentioned, the body contains a structured protein called collagen which helps in providing structural scaffolding to the cells. Collagen also helps in sustaining bone health. Individuals doing heavy exercises and athletes working out for multiple hours depend upon the body’s ability to produce collagen in order to prevent the joints from injury and keep them healthy and strong. A recent study conducted in this regard has advocated the efficacy of collagen protein in the treatment of inflammatory conditions such as osteoarthritis.  
Digestion & Absorption of Proteins
Digestion of proteins is extremely vital for the absorption of amino acids in the body. Enzymes such as pepsin activated by the gastric juices start the digestion of proteins in the stomach. The process of digestion continues and finishes in the small intestine along with the absorption of peptides and amino acids in the bloodstream. 
How much Protein is Recommended?
Regular consumption of a diet with a balanced proportion of nutrients provides enough proteins without any additional protein supplementation. The recommended dose of daily protein requirement varies with individual health and age. However, 2-3 servings of food rich in proteins are enough to satisfy the daily requirement of most of the adults. For example, 1 egg or 1 ounce of cheese or ½ cup cooked beans makes one serving. For infants and older children, protein requirement grows with their age.  
As a guide, dietary recommendation for protein intake is 0.75 grams/kg for women and 0.84 grams/kg for men. For special cases such as old age, pregnancy, lactation, athletes, and weight trainers, the protein requirement may differ from the normal values. 
As stated, protein-rich foods should be consumed adequately on a daily basis as the body does not store it. In absence of sufficient proteins in the diet, the body is at an enhanced risk of protein deficiency. Fluid retention, anemia, shrinkage of muscular tissue are some of the signs of protein deficiency. Protein-energy malnutrition or PEM is used to refer to a range of protein deficiency conditions such as kwashiorkor and marasmus.   
Side Effects of Protein
Weight Gain: High-protein, low-carbohydrate diets are usually proposed for people seeking weight loss. However, negligence in tracking the calorie intake during this regime can cause the amino acids to get converted into fatty acids resulting in weight gain. Focusing only on the protein-rich diet may also lead to the deficiency of other essential nutrients in the body. 
Cardiovascular Problems: High protein diet can aggravate the conditions of heart diseases and cholesterol problems raising it to unhealthy levels. It can also contribute to other medical complications such as gout and can be tough on kidneys. 
Ammonia: Ammonia is a derivative of protein metabolism. Ammonia is very hazardous to the body and hence the body naturally converts it into urea. Kidneys accumulate the urea and flush it out of the body through urine. The protein consumed in excess of daily requirements puts extra strain on the kidney to detoxify the body. 
Heavy Weight Trainers: People who perform strenuous exercises do not need to add additional protein to their diet for extra muscle growth. In reality, the muscle growth happens not by extra protein intake but as a result of muscle exercise which leads to stimulation of muscle tissue.
Bone Health: A diet high in protein may also prove detrimental to the bone health as stated by some researchers. Recent studies have suggested that appropriate intake of calcium along with protein is necessary for healthy bones. Certain ongoing studies also have found that high protein diet increases urinary calcium and may lead to bone resorption. It is generally advised to increase the intake of fruits and vegetables rather than decreasing the protein sources. 
Extremely low intake of carbohydrates with high-protein diet may result in medical complications like muscle wastage and accumulation of ketones in the body.
Proteins are the major life force and structural components present in all the cells of the body. They are the macronutrients which contain nitrogen. If monitored carefully, protein-rich diet along with low carbohydrate intake may assist in weight loss. Along with the quantity of the protein, it is also very important to choose right quality of protein. Quality of proteins refers to the number of amino acids provided by that protein. Animal proteins are easy to digest and hence contribute more in providing the required amino acids to the body. For this reason, they are also referred to as complete dietary protein. Plant proteins, on the other hand, are difficult to digest and lack in one or more amino acids and hence are referred to as incomplete proteins. Insufficiency of protein in the body affects all organs and overall growth and development. It is always advisable to choose a balanced diet with an adequate amount of proteins along with other nutrients to ensure a healthy body and revitalized mind. 
Eat proteins, stay healthy!