The basic building blocks of the human body.
It constitutes about 20% of our total body weight.
Makes the Muscle, hair, skin and connective tissue.
Needed for our immune system, to synthesize neurotransmitters and for the creation and signalling of hormones.
Although our bodies are good at “recycling” protein, we use up protein constantly, so it is important to continually replace it.
Proteins tend to be large molecule made up of several building blocks called amino acids. There are 20 different amino acids which are linked together to form peptides, which are small chains of amino acids. The peptides are then linked together to form polypeptides. One or more polypeptide chains twisted into a 3D shape forms a protein.
Our body can make 11 of them from other compounds already in the body. That leaves nine amino acids that we must get from our diet. Those 9 amino acids are called “Essential Amino Acids.”
Non Essential and Essential Amino Acids
The 11 non-essential amino acids are called “non-essential” because our body can build them from chemicals already present in it. They are very important and our body requires them for several functions.
The remaining nine essential amino acids are called “essential” because our body cannot manufacture them and we have to get them from foods that contain these amino acids.
Why do we need Protein?
Protein is very important molecules in our cells. They are involved in virtually all cell function. There is different kind of protein. Each protein within the body has a specific function as mentioned below-
Antibodies- are specified proteins involved in defending the body from antigens (foreign invaders).
Contractile proteins- are responsible for movement. Examples include actins and myosin. These proteins are involved in muscle contraction and movement.
Enzymes- are protein that facilitates biochemical reactions. Examples include the enzymes lactase and pepsin. Lactase breaks down the sugar lactose found in milk. Pepsin is a digestive enzyme that works in the stomach to break down protein in food.
Hormonal Protein- is messenger proteins that help to coordinate certain bodily activities. For example, Insulin regulates glucose metabolism by controlling the blood- sugar concentration.
Structural Protein- is fibrous and stringy and provides support. For examples Collagen and Elastin provide support for connective tissues such as tendons and ligaments.
Transport Protein- are carrier proteins that move molecules from one place to another around the body. Examples include haemoglobin that transports oxygen through the blood.
Protein Keeps You Satisfied Longer
People who eat more protein tend to be satisfied with less food. A research carried out by “Centre for Diabetes and Endocrinology, Department of machine, University College London” has established that high protein intake in humans includes the releases of anorectic hormone “peptide YY” or “PYY” Which in turn leads to satiety.
Making healthy protein choices is more about the fats that accompany the proteins and the preparation methods than it is about the actual protein.
This means looking for protein sources that are lower in saturated fats, higher in healthier unsaturated fats and prepared in healthy ways. These are commonly referred to as LEANPROTEINS.
This means looking for protein sources tend to contain most of the Essential Amino Acids needed to build new protein in our bodies. They are thus also called COMPLETE PROTEINS. However, protein from such sources as vegetables, fruits and grains tend to lack one or more essential amino acids and are thus called INCOMPLETEPROTEIN.
Of course, fish and chicken may not always be healthy. Fish sticks or fried chicken are not good protein choices because the cooking methods add unhealthy fats and extra calories.
Therefore, deciding the healthy PROTEIN PACKAGE is about balancing the body’s need for both ‘complete’ and ‘lean’ proteins.
Given the constraints of food choices and tastes, getting the correct protein package (low on saturated fat, high on all essential amino acids) often means supplementing our daily diet with a healthy protein supplement.
How much protein do we need each day?
Our protein needs depend on our age, size, and activity level. ICMR recommends the following protein intake for different life stages for Indian population.
Adults – 1.0 gm/kg body weight/day
Children – 1.5 gm/kg body weight/ day
Pregnant/ Lactating women – 1.75 gm/kg body weight/ day
What about Vegetarians?
Proteins from plant sources do not contain all essential amino acids. This means that a diet based on plant protein requires the right combination of protein sources to get enough of all of the essential amino acids. Supplementation with a good lean protein can help.
Do people who exercise need more protein?
People who engage in endurance exercise (such as long distance running) or heavy resistance exercise (such as body-building) benefit from additional protein in their diets.
It is estimated that strength-training athletes need to consume 1.5-2.0 g/kg body weight/day of protein. The increased protein requirement is because during the initial 10-12 days of training. There is a small increase in protein breakdown. Less body protein is broken down if the amount of protein in the diet is increased at this time. After about 12 days of training. Protein balance is restored, and the body is likely to start building extra protein into the muscles if strength training continues.
Other conditions requiring increased protein intake.
Dietary protein requirement is enhanced by such condition as infections, immobilization, surgery, burns, and other injuries frequent intestinal infection by living in polluted atmosphere, chronic amoebiasis, indigestion due to irregular eating schedules, and living in intestinal worm infested areas also increase the need for protein.
Protein at different life stages
The protein intake needs of the human body change at different life stages. To be fit healthy, it is important to take into account the extra demands placed on our body by these changes.
Children’s food needs vary widely, depending on their growth and their level of physical activity. Like energy needs, a child’s total protein, Vitamin and minerals requirements increase with age. Ideally, children should be accumulating stores of protein in preparation for the rapid growth spurt experienced during adolescence.
Children entering their teenage years
The growth spurt as children move into adolescence needs plenty of energy and nutrients. For girls, this generally occurs around 10 to 11 years of age, while for boys it occurs later, at around 12 to 13 years. Protein rich foods that are high in energy should be preferred as they do not lead to excess weight build-up.
Older teenagers and young adults
Moving away from home, starting work and the changing lifestyle that accompanies the late teens and early 20s can cause dietary changes that are not always conducive to good health. The need for performance enhancement and building over all endurance results in higher protein intake requirement. Also this is the time to established healthy eating habits that will be carried on into later life.
Pregnant & Lactating women
A pregnant woman should concentrate on increasing her nutrient intake, rather than her calorie intake, particularly in the first and second trimesters. Breastfeeding mother also need about 75 per cent more protein than normal.
Thinning of the bones is common in post menopausal women because of hormone related changes. Phytoestrogens, which occur naturally in protein rich sources like Soy have beneficial impact on bone health and also negate other post menopausal symptoms.
Many people eat less as they get older; this can make it harder to ensure our diet has enough variety to include all the protein we need. Protein supplementation can help balance nutrient intake and maintain muscle mass. It is also important for and maintains muscle mass. It is also important for good bone and heart health.