Proteins: The Building Blocks of our Body

(At least 10,000 different proteins make us what we are)

Overview

Class I & II Protein

Around the world, billions of people don’t get sufficient protein daily. The amount of food from the ‘Protein Foods Group’ we need to eat depends on our age, sex, and level of physical activity. Most people don’t eat enough food from this group. Protein is also a source of energy like carbohydrates but its main role in the body is growth and repair. Children, teens and pregnant women require sufficient protein for growth and development. We all contain a significant amount of protein in our body. For example, a 80 kg human being is made up of 12.8 kg of protein i.e. 16%.

Complete Protein vs Incomplete Protein

Proteins from meat and other animal products are known as complete protein whereas Proteins from plant products are incomplete proteins. Vegetarian people need to be aware of the fact that their body do not get all the amino acids. People who don’t eat meat, fish, poultry, eggs, or dairy products need to eat a variety of protein-containing foods each day in order to get all the amino acids. Proteins from one plant product don't contain all the amino acids our body needs. But another plant product may have the amino acids that the first one is missing. To get complete protein from plants, we need to eat a variety of plant foods. For instance, eating rice with beans or peanut butter with bread will give us complete protein. Protein from animal sources supply us all the amino acids we need. 

What are Amino Acids & its Types

Amino Acids

Protein foods are broken down into parts called amino acids during digestion because the basic structure of protein is a chain of amino acids. Protein is made up of 20 amino acids, some of which our body can make and others we have to obtain from food. Our bodies make amino acids in two different ways, either from scratch, or by modifying others. Amino acids needed in our body to make new protein. Amino acids are of three types. They are Essential, Nonessential and Conditional.

• Essential amino acids cannot be made by our body, so, must be supplied by food. They do not need to be eaten at one meal. The balance over the whole day is more important. All animal foods, as well as two plant sources i.e. soy protein and quinoa that provides all the necessary amino acids required by the body for good health hence these are called essential amino acids.
• Nonessential amino acids are made by the body from essential amino acids or in the normal breakdown of proteins.
• Whereas Conditional amino acids are needed in times of illness and stress.

In which part Protein is found in our body?

Protein is found all over our body i.e. in muscle, bone, skin, hair. In fact, proteins are found in every living cell of our body. 

Role played by protein in our body

• It makes up the enzymes that power many chemical reactions and the hemoglobin that carries oxygen in our blood.
• Protein helps in repairing cells and make new ones.
• Inside cells, proteins perform many functions, for example helps to break down food for energy, building structures, break down toxins etc.
• Our bodies need protein and amino acids to produce important molecules in our body like enzymes, hormones, neurotransmitters, and antibodies.
• Consuming protein can also increase levels of the hormone glucagon, and glucagon helps in controlling body fat. (Glucagon is released when blood sugar levels goes down. This causes the liver to break down stored glycogen into glucose for the body).
• Protein can also help in liberating free fatty acids from the adipose tissue. This is another way to get fuel for cells and this way our body fat do something useful for us instead of hanging lazily around our midsection.

How to choose protein rich foods

• Some protein rich foods are healthier than others. I am saying this because protein never comes alone in a single food. What comes along with the protein, matters. We can find anything i.e. healthy fats or harmful ones, beneficial fiber or hidden salt. With this knowledge we can make a difference for health. 
• For example: 100 grams boiled lamb and mutton is a great source of protein i.e. about 25 grams worth. But it also delivers about 9 grams of saturated fat. Generally an adult eats a 2,000 calorie per day diet, that means he is taking more than 60 percent of the recommended daily intake for saturated fat.
• Another example 100 grams steak has only about 1.5 grams of saturated fat, but it’s loaded with sodium 1,200 milligrams worth, or about 500 milligrams more than the daily sodium max. 100 grams of fish salmon has about 20 grams of protein and is naturally low in sodium, and contains only 1 gram of saturated fat. Salmon and other fatty fishes are also excellent sources of omega-3 fats (good for our heart). 
• Alternatively, a cup of cooked lentils provides about 18 grams of protein and 15 grams of fiber, and it has virtually no saturated fat or sodium. 

Sources where from we can get?

Protein Rich Foods

100 grams of most protein-rich foods contains 28 grams of protein. For example 100 grams meat, fish or poultry or four large eggs or 100 grams cooked Lentils or 4 tablespoons of peanut butter. Low fat dairy products is also a good source of protein. Whole grains contain more protein than refined or "white" products. Other good sources of protein include, Pinto beans, black beans, kidney beans, split peas, or garbanzo beans, Nuts and seeds, including almonds, hazelnuts, mixed nuts, peanuts, sunflower seeds, or walnuts. (bot note that nuts are also high in fat). Good sources of protein includes: Fish and shellfish, Poultry, Red meat (beef, pork, lamb), Eggs, Nuts, Peanut butter, Nut butters, Seeds, Beans, Peas, Lentils, Soy products (tofu, soya chunks, vegetarian burgers), Milk and Milk products (cheese, cottage cheese, yogurt).

Recommended Daily Allowance

The Institute of Medicine recommends that adults get a minimum of 0.8 grams of protein for every kilogram of body weight per day (or 8 grams of protein for every 20 pounds of body weight). It sets a wide range for acceptable protein intake which is anywhere from 10% to 35%t of calories per day. For example, a person on a 2000 calorie diet could eat 100 grams of protein, which would supply 20% of his total daily calories. In the United States, the recommended daily allowance of protein is 46 grams per day for women over 19 years of age, and 56 grams per day for men over 19 years of age.

Deficiency of protein

• When our body doesn’t get enough protein, it might break down muscle for the fuel it needs. 
• Protein malnutrition leads to the condition known as kwashiorkor. (We have read this already in our school text book.)
• Lack of protein can cause growth failure, loss of muscle mass, decreased immunity, weakening of the heart and respiratory system etc.

What happens if one have too much protein?

Extra protein in our body converts into sugar or fat. However, protein isn’t as easily or quickly converted as carbohydrates, because the thermic effect (the amount of energy require to digest, absorb, transport and store protein) is a lot higher than that of carbohydrates. Because 30% of the protein’s energy goes toward digestion, absorption, and assimilation, while only 8% of carbohydrate’s energy and 3% of fat’s energy do the same.

Role of Protein in weight loss

Protein Shakes for weight loss

Weight gain is a result of the energy taken in being more than the energy burnt off through metabolism or activity, irrespective of the source of the energy (calories). Protein helps to make us feel full after eating i.e. we get satiety. So, including a protein-rich food at each meal can help those people who are trying to lose or maintain their weight. Nevertheless, excessively high protein diets are not recommended, especially those omitting other food groups, such as breads and cereals or dairy products. 

Role of Protein in the life of teenagers, Pregnant, breastfeeding women and Athletes 

• During the adolescent phase protein requirement are high for teenagers to cover both energy requirements and support the growing body.
• Sufficient Protein needed for Pregnant and breastfeeding women in order to support the changes in the mother and foetal growth.
• As protein aids the repair of body tissues, and keeps our immune systems healthy, it helps in recover from illness and can increase resistance to infection for seek people.
• Athletes with heavy training require extra protein to cover the energy costs of their training and to assist in the repair and recovery process after exercise. 
• Strength athletes, who are interested in gaining muscle size and function, require more protein in the early stages of very intensive resistance exercises.