We eat several times a day. It is therefore necessary to know what these foods contain. It is also necessary to know what will happen if we do not get enough of these food constituents. This will help us to select better food items. Nutrients in food Foods contain nourishing substances called Nutrients. There are five main types of nutrients: Carbohydrates, proteins, fats, vitamins and minerals. All of these ingredients supply energy to keep the body going. Vitamins and minerals are required in very small amounts. They do not supply energy but they are very important for thousands of processes going on in the body function smoothly and efficiently. Energy We get energy from food. Our body uses food as energy, just as a motor car uses petrol. We need some basic energy for our bodily functions e.g. beating of heart, breathing through lungs, digestive processes etc. Over and above this we need energy to do our work. If physical work is more, we need more energy and hence need to eat more food. Body energy is measured in kilocalories. Sometimes it is simply called calories. An adult resting in bed needs about 1500 calories as basic energy. Another 100 to 1300 calories are required for his usual physical activity, giving a total of about 2600 - 2800 calories for a normal man. Energy is supplied to the body through carbohydrates, proteins and fats. Carbohydrates These are most common energy sources in the foods of people all over the world. Cereals like rice, wheat, millet, and ragi contain lot of carbohydrates in the form of digestive starches. Potatoes and bananas also have starches. One gram of carbohydrate provides the body with 4 calories of energy. Proteins Proteins are very important to us. Every cell in every part of our body -- muscle, bone, brain, skin & hair -- contains proteins. Proteins are the building blocks of the body. When something gets worn out or used up, proteins do the repair and replacement jobs. One gram of protein gives 4 kilocalories of energy if used as energy. But to burn protein like this as energy is a waste. It is better to eat through carbohydrate to give us the required energy and spare proteins to do the special jobs which only they can carry out. Fats and Oils Fat is burnt in the body as fuel. Fat gives much more energy than carbohydrate or protein. It gives 9 kilocalories per gram burnt, against 4 kilocalories given per gram by either carbohydrates or proteins. Fat is a concentrated form of energy. Its inclusion in the diet increases the calorific value of the diet. Vitamins Vitamins are required in very small quantities. They correct deficiency diseases. (As against illnesses caused by infections).Vitamins are also very important for the proper functioning of the body. Vitamins take part in many vital body processes. Minerals These are minerals or salt. Common salt or sodium chloride is one of the most important minerals required by the body. It is necessary, among other things to regulate blood pressure. Teeth and bones contain calcium which we get in milk and fish. Iron is required to make the red blood cells and also to build muscles. It is found in green leafy vegetables, meat, eggs, raisins, dates etc. Vitamins and minerals come mostly from fruits, raw vegetables and green leafy vegetables. If a good diet is eaten every day, consisting of all these 5 constituents in required quantities, there is no need to buy expensive tonics and special foods. Water Body also requires plenty of water every day. Almost two thirds of our bodies are made up of water. Many chemical processes in the body require water. Water also regulates the body temperature. Drinking 8 glasses of water / 1.5 to 2 liters of water per day is a good practice. We get water both by drinking it and from many food items. Milk is 80 to 90 % water, meat, eggs & potatoes are 70 % water. Fruits and vegetables are mostly water too.
Please Rate this Article 5 out of 54 out of 53 out of 52 out of 51 out of 5
Not yet Rated
