CBSE Class 12 Physical Education Sports And Nutrition Notes Set 04

Sports and Nutrition

Balanced Diet and Nutrition

A balanced diet is that which contains the proper amount of each nutrient. A balanced diet consists of all essential food constituents i.e. protein, carbohydrates, fats, vitamins and minerals in correct proportion.

Nutrition is the science that deals with food and its uses by the body. Food supplies the energy for every action our body undertakes, from eating bananas to running a race. Food also provides material that our body needs to build and repair its tissues and to regulate the functions of its organs and systems. The chemicals in food which our body needs and are essential for the growth and replacement of tissues are called nutrients.

Macro and Micro Nutrients

Macro Nutrients

The macro nutrients include carbohydrates, proteins and fats.

Carbohydrates

Carbohydrates are the main source of energy in all activities that we do. The elements of carbohydrates are carbon, hydrogen and oxygen. Carbohydrates are organic compounds which are important for our digestive process. They require less water in the diet for being digested. There primary function is to provide energy to the body, especially to the brain and nervous system.

There are two main types of carbohydrates i.e. simple carbohydrates and complex carbohydrates.

Proteins

Proteins are the basic constituents of our cells. They are large molecules, so they cannot get directly into our blood. So, proteins in our food are turned into amino acid by our digestive system. The human body needs 20 different amino acids to maintain good health and normal functioning, out of which 11 are manufactured by the body. So, 9 remaining amino acids sholuld be available from the proteins in our diet. Proteins form tissues, repair the broken tissues, regulate balance of water and oxygen etc. They are body building foods. Foods rich in proteins are eggs, meat, fish and dairy products as well as pulses, nuts and cereals.

Fats

Fats contain hydrogen, carbon and oxygen. These are the most concentrated source of energy in food. Fats have a very high energy content. Foods rich in fats are butter, oil, sausage, cheese, fish, chocolate, olives and nuts. If we do not take enough exercise on a regular basis, we become overweight or even ill. Many fats are unhealthy, such as trans-fats in deep fried foods.

Micro Nutrients

Micro nutrients are vitamins, minerals and secondary plant compounds.

Vitamins

Vitamins are compounds of carbon which are essential for the normal growth and working of the body. They are required in very small quantities. Many of them can be stored in the body for months or even years but others need to be freshly absorbed every day. There are two groups of vitamins i.e. fat soluble and water soluble:

• (i) Fat Soluble Vitamins: These vitamins are composed of carbon, hydrogen and oxygen and are soluble in fats, such as vitamin A, vitamin D, vitamin E and vitamin K. The fat soluble vitamins are
  • Vitamin A: This is essential for normal growth of the body. Deficiency of vitamin A leads to night blindness and also affects the kidneys, nervous system and digestive system. Sources are milk, curd, ghee, egg yolk, fish, tomato, papaya, green vegetables, orange, spinach, carrot and pumpkin.
  • Vitamin D: This is essential for the formation of healthy teeth and bones. The presence of this vitamin in the body enables the body to absorb calcium and phosphorus. Its deficiency causes rickets, softness of bones and teeth diseases. Sources are egg yolk, fish, sunlight, vegetables, cod liver oil, milk, cream and butter.
  • Vitamin E: This is essential in increasing the fertility among men and women as well as proper functioning of adrenal and sex glands. Its deficiency causes weakness in muscles and heart. Sources are green vegetables, sprouts, coconut oil, dry and fresh fruits, milk, meat, butter and maize.
  • Vitamin K: This is helpful in the clotting of blood. Its deficiency causes anaemia and blood does not clot easily. Sources are cauliflower, spinach, cabbage, tomato, potato, wheat, egg and meat.
• (ii) Water Soluble Vitamins: These vitamins are composed of nitrogen and sulphur and are soluble in water, such as vitamin B complex and vitamin C.
  • Vitamin B Complex: There are 12 vitamins in this group; some of them are B₁, B₂, B₃, B₆ and B₁₂. They are necessary for growth, proper functioning of heart, liver, kidney and maintaining smooth skin. Its deficiency causes Beri-Beri disease, Pellagra and also decreases immunity. Sources are wheat, milk, nuts, peas, egg yolk and sprouts.
    • Vitamin B₁ (Thiamin): It helps to release energy from foods, promotes normal appetite, and is important in maintaining proper nervous system function.
    • Vitamin B₂ (Riboflavin): It helps to release energy from foods, promotes good vision and maintains a healthy skin. It also helps to convert the amino acid tryptophan (which makes up protein) into niacin.
    • Vitamin B₃ (Niacin): It works with other B-complex vitamins to metabolise food and provides energy for the body. Vitamin B₃ is involved in energy production, normal enzyme function, digestion, promoting normal appetite, healthy skin and nerves.
    • Vitamin B₆ (Pyridoxine): It is a key factor in protein and glucose metabolism as well as in the formation of haemoglobin. Haemoglobin is a component of red blood cells which carries oxygen. Vitamin B₆ is also involved in keeping the lymph nodes and thymus gland healthy.
    • Vitamin B₁₂ (Cobalamin): It aids in the building of genetic material, production of normal red blood cells, and maintenance of the nervous system.
  • Vitamin C: It is also called Ascorbic acid and is a water-soluble vitamin. It cannot be stored in the body. Most plants and animals can produce their own vitamin C but humans cannot. Vitamin C is needed for proper growth, development, and healing of wounds. It is used to make the collagen tissue for healthy teeth, gums, blood vessels and bones. Deficiency of vitamin C causes scurvy.

Minerals

Minerals contain elements needed by our body in small quantities. But these are essential for proper growth and functioning of the body. A shortage of minerals can have severe effects on health. For instance, a long-term shortage of foods containing iodine in people leads to thyroid gland diseases. Some of the important minerals are

• (i) Iron: It is important for the formation of haemoglobin. Its deficiency leads to anaemia. Its sources are meat, eggs and dry fruits.
• (ii) Calcium: It is needed for the formation of strong bones, teeth and also for clotting of blood and muscle contraction. Its deficiency causes rickets and asthma. Its sources are milk, cheese and oranges.
• (iii) Phosphorus: It is required for development of strong bones and teeth and also for making energy. Its sources are egg, fish, meat and unpolished rice.
• (iv) Potassium: It is important for growth and keeping cells and blood healthy. Its deficiency weakens the muscles of the body. Its sources are carrot, beet root, onion, tomato, orange and mango.
• (v) Sodium: It is needed for the proper functioning of the nervous system. Its sources are milk and milk products, meat and eggs.
• (vi) Iodine: It is essential for proper thyroid function. Its deficiency causes goitre and sources are seafood and salt.
• (vii) Fluorine: It is important to make the enamel (polish) of the teeth hard and prevents dental caries.
• (viii) Copper: It is helpful in formation of red blood cells, connective tissue and nerve fibre formation and functioning.
• (ix) Zinc: It is required for insulin production and also for functioning of male prostate, digestion and metabolism.

Food components, whether they are nutritive (providing calories) or non-nutritive (not providing calories), are present in a multitude of food and beverages.

Non-nutritive components of food not only provide a flavour to foods but they are also used to preserve foods (in jams or jellies), provide body bulk and texture (in ice-cream and baked goods), enhance other flavours (e.g. salty) and aid in fermentation (in breads and pickles).

The nutritive components of diet are proteins, carbohydrates, fats, vitamins and minerals.

Non-nutritive components do not contribute to the energy, calories or nutrition of the body. Some non-nutritive components are essential for the body while others harm the body. Colour compounds, flavour compounds, food additives, plant compounds, water and roughage or fibre are some non-nutritive components of diet.

Nutritive and Non-Nutritive Components of Diet

Food components, whether they are nutritive (providing calories) or non-nutritive (not providing calories), are present in a multitude of food and beverages.

Non-nutritive components of food not only provide a flavour to foods but they are also used to preserve foods (in jams or jellies), provide body bulk and texture (in ice-cream and baked goods), enhance other flavours (e.g. salty) and aid in fermentation (in breads and pickles).

The nutritive components of diet are proteins, carbohydrates, fats, vitamins and minerals.

Non-nutritive components do not contribute to the energy, calories or nutrition of the body. Some non-nutritive components are essential for the body while others harm the body. Colour compounds, flavour compounds, food additives, plant compounds, water and roughage or fibre are some non-nutritive components of diet.