As proteins, carbohydrates, fats, vitamins, minerals, salt and water are nutritious elements and so they are important in our diet: A balance of these elements in diet keeps healthy. Different are the functions of these elements.
- Protein : It is an organic compound of hydrogen, carbon, oxygen and. nitrogen. It also contains sulfur, iron, phosphorous and iodine. It produces tissues and new cells. As it forms the basic framework of every cell and so of the organism, it is described as the 'stuff of life'. Protein comes from two sources-plants and animals. This is found in milk, meat, fish, egg, pulse, wheat, paneer, curd, butter, barley, gram, pease, fruits, soya bean, banana, etc. Protein develops the body, repairs the breaks of the body through Metabolism: It makes $75 \%$ of solid parts of the body. Deficiency of proteins cause lack of growth.
- Carbohydrate : It is an organic compound of carbon, oxygen and hydrogen. These are important elements which produces energy in food. Carbohydrates are found in sugarcane, potato, rice, maize, honey, wheat, - barley, grapes, banana, fruits and vegetables etc.
It produces energy in the body and helps the growth of body. it supplies more than 50% of the energy contents and of most diet. The main end product of carbohydrate digestion is glucose at 100 mg per ml. Extra glucose, if any, is converted into glycogen in liver, Deficiency of Carbohydrate cause weakness.
- Fat : Like carbohydrate, it is also organic compound of carbon, hydrogen and oxygen but in fact oxygen is less than that of carbohydrate. It is major source of energy. Its main decomposer are glycerol and fatty acids. It forms tissues. Owing to fat the body appears smooth. It is found in coconut, groundnut, badam, mustard oil, ghee, butter, milk, etc. Deficiency of fat causes weakness.
- Vitamin : Vitamins are complicated organic compounds. These control the functions regarding energy. Vitamins preventive of diseases.
It does not produce energy but it behave like catalyst for production of energy. Nearly 20 types of vitamins have been invented but 6 (Vitamin $A, B, C, D, E$ and $K$ ) are very important. On account of the deficiency of vitamin several diseases are caused. Vitamins are found in milk, egg, meat, green vegetable, butter, A.D. oil, corn, pulse, groundnut, tomato, fruits, etc.
- Mineral Salt : It is an inorganic of food. It plays a vital role in preserving the physical integrity of cells and, tissues which help the maintenance of good health. Deficiency of mineral salt causes several diseases like Gout, Goiter etc. Calcium, phosphorus, potassium, sodium, iron, iodine, sulpher etc. are main mineral salt. These built teeth, bones; helps in blood clotting & makes balance of acid-base in the body.
- Water : Water is essential for life, it is base of life. Without water no living beings can exist. This makes 60 to $90 \%$ of protoplasm, works as solvent for many compound, helps carry the essential materials in the different parts of the body the eliminate the excretory products from the body. It controls the temperature of the body and participate in respiration etc.
